# This set of tests is not Perl-compatible. It checks on special features
# of PCRE2's API, error diagnostics, and the compiled code of some patterns.
# It also checks the non-Perl syntax that PCRE2 supports (Python, .NET, 
# Oniguruma). There are also some tests where PCRE2 and Perl differ, 
# either because PCRE2 can't be compatible, or there is a possible Perl 
# bug.

# NOTE: This is a non-UTF set of tests. When UTF support is needed, use
# test 5. 

#forbid_utf

# Test binary zeroes in the pattern

# /a\0B/ where 0 is a binary zero
/61 5c 00 62/B,hex
------------------------------------------------------------------
        Bra
        a\x00b
        Ket
        End
------------------------------------------------------------------
    a\x{0}b
 0: a\x00b

# /a0b/ where 0 is a binary zero
/61 00 62/B,hex
------------------------------------------------------------------
        Bra
        a\x00b
        Ket
        End
------------------------------------------------------------------
    a\x{0}b
 0: a\x00b

# /(?#B0C)DE/ where 0 is a binary zero
/28 3f 23 42 00 43 29 44 45/B,hex
------------------------------------------------------------------
        Bra
        DE
        Ket
        End
------------------------------------------------------------------
    DE
 0: DE

/(a)b|/I
Capturing subpattern count = 1
May match empty string
Subject length lower bound = 0

/abc/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3
    abc
 0: abc
    defabc
 0: abc
    abc\=anchored
 0: abc
    *** Failers
No match
    defabc\=anchored
No match
    ABC
No match

/^abc/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3
    abc
 0: abc
    abc\=anchored
 0: abc
    *** Failers
No match
    defabc
No match
    defabc\=anchored
No match

/a+bc/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3

/a*bc/I
Capturing subpattern count = 0
Starting code units: a b 
Last code unit = 'c'
Subject length lower bound = 2

/a{3}bc/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 5

/(abc|a+z)/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 2

/^abc$/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3
    abc
 0: abc
    *** Failers
No match
    def\nabc
No match

/ab\idef/
Failed: error 103 at offset 3: unrecognized character follows \

/(?X)ab\idef/
Failed: error 111 at offset 2: unrecognized character after (? or (?-

/x{5,4}/
Failed: error 104 at offset 5: numbers out of order in {} quantifier

/z{65536}/
Failed: error 105 at offset 7: number too big in {} quantifier

/[abcd/
Failed: error 106 at offset 5: missing terminating ] for character class

/[\B]/B
Failed: error 107 at offset 2: invalid escape sequence in character class

/[\R]/B
Failed: error 107 at offset 2: invalid escape sequence in character class

/[\X]/B
Failed: error 107 at offset 2: invalid escape sequence in character class

/[z-a]/
Failed: error 108 at offset 3: range out of order in character class

/^*/
Failed: error 109 at offset 1: nothing to repeat

/(abc/
Failed: error 114 at offset 4: missing closing parenthesis

/(?# abc/
Failed: error 118 at offset 7: missing ) after (?# comment

/(?z)abc/
Failed: error 111 at offset 2: unrecognized character after (? or (?-

/.*b/I
Capturing subpattern count = 0
First code unit at start or follows newline
Last code unit = 'b'
Subject length lower bound = 1

/.*?b/I
Capturing subpattern count = 0
First code unit at start or follows newline
Last code unit = 'b'
Subject length lower bound = 1

/cat|dog|elephant/I
Capturing subpattern count = 0
Starting code units: c d e 
Subject length lower bound = 3
    this sentence eventually mentions a cat
 0: cat
    this sentences rambles on and on for a while and then reaches elephant
 0: elephant

/cat|dog|elephant/I
Capturing subpattern count = 0
Starting code units: c d e 
Subject length lower bound = 3
    this sentence eventually mentions a cat
 0: cat
    this sentences rambles on and on for a while and then reaches elephant
 0: elephant

/cat|dog|elephant/Ii
Capturing subpattern count = 0
Options: caseless
Starting code units: C D E c d e 
Subject length lower bound = 3
    this sentence eventually mentions a CAT cat
 0: CAT
    this sentences rambles on and on for a while to elephant ElePhant
 0: elephant

/a|[bcd]/I
Capturing subpattern count = 0
Starting code units: a b c d 
Subject length lower bound = 1

/(a|[^\dZ])/I
Capturing subpattern count = 1
Starting code units: \x00 \x01 \x02 \x03 \x04 \x05 \x06 \x07 \x08 \x09 \x0a 
  \x0b \x0c \x0d \x0e \x0f \x10 \x11 \x12 \x13 \x14 \x15 \x16 \x17 \x18 \x19 
  \x1a \x1b \x1c \x1d \x1e \x1f \x20 ! " # $ % & ' ( ) * + , - . / : ; < = > 
  ? @ A B C D E F G H I J K L M N O P Q R S T U V W X Y [ \ ] ^ _ ` a b c d 
  e f g h i j k l m n o p q r s t u v w x y z { | } ~ \x7f \x80 \x81 \x82 \x83 
  \x84 \x85 \x86 \x87 \x88 \x89 \x8a \x8b \x8c \x8d \x8e \x8f \x90 \x91 \x92 
  \x93 \x94 \x95 \x96 \x97 \x98 \x99 \x9a \x9b \x9c \x9d \x9e \x9f \xa0 \xa1 
  \xa2 \xa3 \xa4 \xa5 \xa6 \xa7 \xa8 \xa9 \xaa \xab \xac \xad \xae \xaf \xb0 
  \xb1 \xb2 \xb3 \xb4 \xb5 \xb6 \xb7 \xb8 \xb9 \xba \xbb \xbc \xbd \xbe \xbf 
  \xc0 \xc1 \xc2 \xc3 \xc4 \xc5 \xc6 \xc7 \xc8 \xc9 \xca \xcb \xcc \xcd \xce 
  \xcf \xd0 \xd1 \xd2 \xd3 \xd4 \xd5 \xd6 \xd7 \xd8 \xd9 \xda \xdb \xdc \xdd 
  \xde \xdf \xe0 \xe1 \xe2 \xe3 \xe4 \xe5 \xe6 \xe7 \xe8 \xe9 \xea \xeb \xec 
  \xed \xee \xef \xf0 \xf1 \xf2 \xf3 \xf4 \xf5 \xf6 \xf7 \xf8 \xf9 \xfa \xfb 
  \xfc \xfd \xfe \xff 
Subject length lower bound = 1

/(a|b)*[\s]/I
Capturing subpattern count = 1
Starting code units: \x09 \x0a \x0b \x0c \x0d \x20 a b 
Subject length lower bound = 1

/(ab\2)/
Failed: error 115 at offset 6: reference to non-existent subpattern

/{4,5}abc/
Failed: error 109 at offset 4: nothing to repeat

/(a)(b)(c)\2/I
Capturing subpattern count = 3
Max back reference = 2
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 4
    abcb
 0: abcb
 1: a
 2: b
 3: c
    abcb\=ovector=0
Matched, but too many substrings
    abcb\=ovector=1
Matched, but too many substrings
 0: abcb
    abcb\=ovector=2
Matched, but too many substrings
 0: abcb
 1: a
    abcb\=ovector=3
Matched, but too many substrings
 0: abcb
 1: a
 2: b
    abcb\=ovector=4
 0: abcb
 1: a
 2: b
 3: c

/(a)bc|(a)(b)\2/I
Capturing subpattern count = 3
Max back reference = 2
First code unit = 'a'
Subject length lower bound = 3
    abc
 0: abc
 1: a
    abc\=ovector=0
Matched, but too many substrings
    abc\=ovector=1
Matched, but too many substrings
 0: abc
    abc\=ovector=2
 0: abc
 1: a
    aba
 0: aba
 1: <unset>
 2: a
 3: b
    aba\=ovector=0
Matched, but too many substrings
    aba\=ovector=1
Matched, but too many substrings
 0: aba
    aba\=ovector=2
Matched, but too many substrings
 0: aba
 1: <unset>
    aba\=ovector=3
Matched, but too many substrings
 0: aba
 1: <unset>
 2: a
    aba\=ovector=4
 0: aba
 1: <unset>
 2: a
 3: b

/abc$/I,dollar_endonly
Capturing subpattern count = 0
Options: dollar_endonly
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3
    abc
 0: abc
    *** Failers
No match
    abc\n
No match
    abc\ndef
No match

/(a)(b)(c)(d)(e)\6/
Failed: error 115 at offset 17: reference to non-existent subpattern

/the quick brown fox/I
Capturing subpattern count = 0
First code unit = 't'
Last code unit = 'x'
Subject length lower bound = 19
    the quick brown fox
 0: the quick brown fox
    this is a line with the quick brown fox
 0: the quick brown fox

/the quick brown fox/I,anchored
Capturing subpattern count = 0
Options: anchored
Subject length lower bound = 19
    the quick brown fox
 0: the quick brown fox
    *** Failers
No match
    this is a line with the quick brown fox
No match

/ab(?z)cd/
Failed: error 111 at offset 4: unrecognized character after (? or (?-

/^abc|def/I
Capturing subpattern count = 0
Subject length lower bound = 3
    abcdef
 0: abc
    abcdef\=notbol
 0: def

/.*((abc)$|(def))/I
Capturing subpattern count = 3
First code unit at start or follows newline
Subject length lower bound = 3
    defabc
 0: defabc
 1: abc
 2: abc
    defabc\=noteol
 0: def
 1: def
 2: <unset>
 3: def

/)/
Failed: error 122 at offset 0: unmatched closing parenthesis

/a[]b/
Failed: error 106 at offset 4: missing terminating ] for character class

/[^aeiou ]{3,}/I
Capturing subpattern count = 0
Starting code units: \x00 \x01 \x02 \x03 \x04 \x05 \x06 \x07 \x08 \x09 \x0a 
  \x0b \x0c \x0d \x0e \x0f \x10 \x11 \x12 \x13 \x14 \x15 \x16 \x17 \x18 \x19 
  \x1a \x1b \x1c \x1d \x1e \x1f ! " # $ % & ' ( ) * + , - . / 0 1 2 3 4 5 6 
  7 8 9 : ; < = > ? @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z [ 
  \ ] ^ _ ` b c d f g h j k l m n p q r s t v w x y z { | } ~ \x7f \x80 \x81 
  \x82 \x83 \x84 \x85 \x86 \x87 \x88 \x89 \x8a \x8b \x8c \x8d \x8e \x8f \x90 
  \x91 \x92 \x93 \x94 \x95 \x96 \x97 \x98 \x99 \x9a \x9b \x9c \x9d \x9e \x9f 
  \xa0 \xa1 \xa2 \xa3 \xa4 \xa5 \xa6 \xa7 \xa8 \xa9 \xaa \xab \xac \xad \xae 
  \xaf \xb0 \xb1 \xb2 \xb3 \xb4 \xb5 \xb6 \xb7 \xb8 \xb9 \xba \xbb \xbc \xbd 
  \xbe \xbf \xc0 \xc1 \xc2 \xc3 \xc4 \xc5 \xc6 \xc7 \xc8 \xc9 \xca \xcb \xcc 
  \xcd \xce \xcf \xd0 \xd1 \xd2 \xd3 \xd4 \xd5 \xd6 \xd7 \xd8 \xd9 \xda \xdb 
  \xdc \xdd \xde \xdf \xe0 \xe1 \xe2 \xe3 \xe4 \xe5 \xe6 \xe7 \xe8 \xe9 \xea 
  \xeb \xec \xed \xee \xef \xf0 \xf1 \xf2 \xf3 \xf4 \xf5 \xf6 \xf7 \xf8 \xf9 
  \xfa \xfb \xfc \xfd \xfe \xff 
Subject length lower bound = 3
    co-processors, and for
 0: -pr

/<.*>/I
Capturing subpattern count = 0
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 2
    abc<def>ghi<klm>nop
 0: <def>ghi<klm>

/<.*?>/I
Capturing subpattern count = 0
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 2
    abc<def>ghi<klm>nop
 0: <def>

/<.*>/I,ungreedy
Capturing subpattern count = 0
Options: ungreedy
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 2
    abc<def>ghi<klm>nop
 0: <def>

/(?U)<.*>/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: ungreedy
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 2
    abc<def>ghi<klm>nop
 0: <def>

/<.*?>/I,ungreedy
Capturing subpattern count = 0
Options: ungreedy
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 2
    abc<def>ghi<klm>nop
 0: <def>ghi<klm>

/={3,}/I,ungreedy
Capturing subpattern count = 0
Options: ungreedy
First code unit = '='
Last code unit = '='
Subject length lower bound = 3
    abc========def
 0: ===

/(?U)={3,}?/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: ungreedy
First code unit = '='
Last code unit = '='
Subject length lower bound = 3
    abc========def
 0: ========

/(?<!bar|cattle)foo/I
Capturing subpattern count = 0
Max lookbehind = 6
First code unit = 'f'
Last code unit = 'o'
Subject length lower bound = 3
    foo
 0: foo
    catfoo
 0: foo
    *** Failers
No match
    the barfoo
No match
    and cattlefoo
No match

/(?<=a+)b/
Failed: error 125 at offset 6: lookbehind assertion is not fixed length

/(?<=aaa|b{0,3})b/
Failed: error 125 at offset 14: lookbehind assertion is not fixed length

/(?<!(foo)a\1)bar/
Failed: error 125 at offset 12: lookbehind assertion is not fixed length

/(?i)abc/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: caseless
First code unit = 'a' (caseless)
Last code unit = 'c' (caseless)
Subject length lower bound = 3

/(a|(?m)a)/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 1

/(?i)^1234/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored caseless
Subject length lower bound = 4

/(^b|(?i)^d)/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/(?s).*/I
Capturing subpattern count = 0
May match empty string
Compile options: <none>
Overall options: anchored dotall
Subject length lower bound = 0

/[abcd]/I
Capturing subpattern count = 0
Starting code units: a b c d 
Subject length lower bound = 1

/(?i)[abcd]/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: caseless
Starting code units: A B C D a b c d 
Subject length lower bound = 1

/(?m)[xy]|(b|c)/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: multiline
Starting code units: b c x y 
Subject length lower bound = 1

/(^a|^b)/Im
Capturing subpattern count = 1
Options: multiline
First code unit at start or follows newline
Subject length lower bound = 1

/(?i)(^a|^b)/Im
Capturing subpattern count = 1
Compile options: multiline
Overall options: caseless multiline
First code unit at start or follows newline
Subject length lower bound = 1

/(a)(?(1)a|b|c)/
Failed: error 127 at offset 13: conditional group contains more than two branches

/(?(?=a)a|b|c)/
Failed: error 127 at offset 12: conditional group contains more than two branches

/(?(1a)/
Failed: error 126 at offset 4: malformed number or name after (?(

/(?(1a))/
Failed: error 126 at offset 4: malformed number or name after (?(

/(?(?i))/
Failed: error 128 at offset 3: assertion expected after (?(

/(?(abc))/
Failed: error 115 at offset 7: reference to non-existent subpattern

/(?(?<ab))/
Failed: error 142 at offset 7: syntax error in subpattern name (missing terminator)

/((?s)blah)\s+\1/I
Capturing subpattern count = 1
Max back reference = 1
First code unit = 'b'
Last code unit = 'h'
Subject length lower bound = 9

/((?i)blah)\s+\1/I
Capturing subpattern count = 1
Max back reference = 1
First code unit = 'b' (caseless)
Last code unit = 'h' (caseless)
Subject length lower bound = 9

/((?i)b)/IB
------------------------------------------------------------------
        Bra
        CBra 1
     /i b
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
First code unit = 'b' (caseless)
Subject length lower bound = 1

/(a*b|(?i:c*(?-i)d))/I
Capturing subpattern count = 1
Starting code units: C a b c d 
Subject length lower bound = 1

/a$/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1
    a
 0: a
    a\n
 0: a
    *** Failers
No match
    a\=noteol
No match
    a\n\=noteol
No match

/a$/Im
Capturing subpattern count = 0
Options: multiline
First code unit = 'a'
Subject length lower bound = 1
    a
 0: a
    a\n
 0: a
    a\n\=noteol
 0: a
    *** Failers
No match
    a\=noteol
No match

/\Aabc/Im
Capturing subpattern count = 0
Max lookbehind = 1
Compile options: multiline
Overall options: anchored multiline
Subject length lower bound = 3

/^abc/Im
Capturing subpattern count = 0
Options: multiline
First code unit at start or follows newline
Last code unit = 'c'
Subject length lower bound = 3

/^((a+)(?U)([ab]+)(?-U)([bc]+)(\w*))/I
Capturing subpattern count = 5
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3
  aaaaabbbbbcccccdef
 0: aaaaabbbbbcccccdef
 1: aaaaabbbbbcccccdef
 2: aaaaa
 3: b
 4: bbbbccccc
 5: def

/(?<=foo)[ab]/I
Capturing subpattern count = 0
Max lookbehind = 3
Starting code units: a b 
Subject length lower bound = 1

/(?<!foo)(alpha|omega)/I
Capturing subpattern count = 1
Max lookbehind = 3
Starting code units: a o 
Last code unit = 'a'
Subject length lower bound = 5

/(?!alphabet)[ab]/I
Capturing subpattern count = 0
Starting code units: a b 
Subject length lower bound = 1

/(?<=foo\n)^bar/Im
Capturing subpattern count = 0
Max lookbehind = 4
Contains explicit CR or LF match
Options: multiline
Last code unit = 'r'
Subject length lower bound = 3
    foo\nbarbar
 0: bar
    ***Failers
No match
    rhubarb
No match
    barbell
No match
    abc\nbarton
No match

/^(?<=foo\n)bar/Im
Capturing subpattern count = 0
Max lookbehind = 4
Contains explicit CR or LF match
Options: multiline
First code unit at start or follows newline
Last code unit = 'r'
Subject length lower bound = 3
    foo\nbarbar
 0: bar
    ***Failers
No match
    rhubarb
No match
    barbell
No match
    abc\nbarton
No match

/(?>^abc)/Im
Capturing subpattern count = 0
Options: multiline
First code unit at start or follows newline
Last code unit = 'c'
Subject length lower bound = 3
    abc
 0: abc
    def\nabc
 0: abc
    *** Failers
No match
    defabc
No match

/(?<=ab(c+)d)ef/
Failed: error 125 at offset 11: lookbehind assertion is not fixed length

/(?<=ab(?<=c+)d)ef/
Failed: error 125 at offset 12: lookbehind assertion is not fixed length

/(?<=ab(c|de)f)g/
Failed: error 125 at offset 13: lookbehind assertion is not fixed length

/The next three are in testinput2 because they have variable length branches/

/(?<=bullock|donkey)-cart/I
Capturing subpattern count = 0
Max lookbehind = 7
First code unit = '-'
Last code unit = 't'
Subject length lower bound = 5
    the bullock-cart
 0: -cart
    a donkey-cart race
 0: -cart
    *** Failers
No match
    cart
No match
    horse-and-cart
No match

/(?<=ab(?i)x|y|z)/I
Capturing subpattern count = 0
Max lookbehind = 3
May match empty string
Subject length lower bound = 0

/(?>.*)(?<=(abcd)|(xyz))/I
Capturing subpattern count = 2
Max lookbehind = 4
May match empty string
Subject length lower bound = 0
    alphabetabcd
 0: alphabetabcd
 1: abcd
    endingxyz
 0: endingxyz
 1: <unset>
 2: xyz

/(?<=ab(?i)x(?-i)y|(?i)z|b)ZZ/I
Capturing subpattern count = 0
Max lookbehind = 4
First code unit = 'Z'
Last code unit = 'Z'
Subject length lower bound = 2
    abxyZZ
 0: ZZ
    abXyZZ
 0: ZZ
    ZZZ
 0: ZZ
    zZZ
 0: ZZ
    bZZ
 0: ZZ
    BZZ
 0: ZZ
    *** Failers
No match
    ZZ
No match
    abXYZZ
No match
    zzz
No match
    bzz
No match

/(?<!(foo)a)bar/I
Capturing subpattern count = 1
Max lookbehind = 4
First code unit = 'b'
Last code unit = 'r'
Subject length lower bound = 3
    bar
 0: bar
    foobbar
 0: bar
    *** Failers
No match
    fooabar
No match

/This one is here because Perl behaves differently; see also the following/I
Capturing subpattern count = 0
First code unit = 'T'
Last code unit = 'g'
Subject length lower bound = 73

/^(a\1?){4}$/I
Capturing subpattern count = 1
Max back reference = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 4
    aaaa
No match
    aaaaaa
No match
    
/Perl does not fail these two for the final subjects. Neither did PCRE until/
/release 8.01. The problem is in backtracking into a subpattern that contains/
No match
/a recursive reference to itself. PCRE has now made these into atomic patterns./
No match

/^(xa|=?\1a){2}$/
    xa=xaa
 0: xa=xaa
 1: =xaa
    ** Failers
No match
    xa=xaaa
No match

/^(xa|=?\1a)+$/
    xa=xaa
 0: xa=xaa
 1: =xaa
    ** Failers
No match
    xa=xaaa
No match

/These are syntax tests from Perl 5.005/I
Capturing subpattern count = 0
First code unit = 'T'
Last code unit = '5'
Subject length lower bound = 38

/a[b-a]/
Failed: error 108 at offset 4: range out of order in character class

/a[]b/
Failed: error 106 at offset 4: missing terminating ] for character class

/a[/
Failed: error 106 at offset 2: missing terminating ] for character class

/*a/
Failed: error 109 at offset 0: nothing to repeat

/(*)b/
Failed: error 109 at offset 1: nothing to repeat

/abc)/
Failed: error 122 at offset 3: unmatched closing parenthesis

/(abc/
Failed: error 114 at offset 4: missing closing parenthesis

/a**/
Failed: error 109 at offset 2: nothing to repeat

/)(/
Failed: error 122 at offset 0: unmatched closing parenthesis

/\1/
Failed: error 115 at offset 2: reference to non-existent subpattern

/\2/
Failed: error 115 at offset 2: reference to non-existent subpattern

/(a)|\2/
Failed: error 115 at offset 6: reference to non-existent subpattern

/a[b-a]/Ii
Failed: error 108 at offset 4: range out of order in character class

/a[]b/Ii
Failed: error 106 at offset 4: missing terminating ] for character class

/a[/Ii
Failed: error 106 at offset 2: missing terminating ] for character class

/*a/Ii
Failed: error 109 at offset 0: nothing to repeat

/(*)b/Ii
Failed: error 109 at offset 1: nothing to repeat

/abc)/Ii
Failed: error 122 at offset 3: unmatched closing parenthesis

/(abc/Ii
Failed: error 114 at offset 4: missing closing parenthesis

/a**/Ii
Failed: error 109 at offset 2: nothing to repeat

/)(/Ii
Failed: error 122 at offset 0: unmatched closing parenthesis

/:(?:/
Failed: error 114 at offset 4: missing closing parenthesis

/(?<%)b/
Failed: error 124 at offset 3: unrecognized character after (?<

/a(?{)b/
Failed: error 111 at offset 3: unrecognized character after (? or (?-

/a(?{{})b/
Failed: error 111 at offset 3: unrecognized character after (? or (?-

/a(?{}})b/
Failed: error 111 at offset 3: unrecognized character after (? or (?-

/a(?{"{"})b/
Failed: error 111 at offset 3: unrecognized character after (? or (?-

/a(?{"{"}})b/
Failed: error 111 at offset 3: unrecognized character after (? or (?-

/(?(1?)a|b)/
Failed: error 126 at offset 4: malformed number or name after (?(

/[a[:xyz:/
Failed: error 106 at offset 8: missing terminating ] for character class

/(?<=x+)y/
Failed: error 125 at offset 6: lookbehind assertion is not fixed length

/a{37,17}/
Failed: error 104 at offset 7: numbers out of order in {} quantifier

/abc/\
Failed: error 101 at offset 4: \ at end of pattern

/abc/\i
Failed: error 101 at offset 4: \ at end of pattern

/(a)bc(d)/I
Capturing subpattern count = 2
First code unit = 'a'
Last code unit = 'd'
Subject length lower bound = 4
    abcd
 0: abcd
 1: a
 2: d
    abcd\=copy=2
 0: abcd
 1: a
 2: d
 2C d (1)
    abcd\=copy=5
 0: abcd
 1: a
 2: d
copy substring 5 failed (-47): unknown or unset substring

/(.{20})/I
Capturing subpattern count = 1
Subject length lower bound = 20
    abcdefghijklmnopqrstuvwxyz
 0: abcdefghijklmnopqrst
 1: abcdefghijklmnopqrst
    abcdefghijklmnopqrstuvwxyz\=copy=1
 0: abcdefghijklmnopqrst
 1: abcdefghijklmnopqrst
 1C abcdefghijklmnopqrst (20)
    abcdefghijklmnopqrstuvwxyz\=get=1
 0: abcdefghijklmnopqrst
 1: abcdefghijklmnopqrst
 1G abcdefghijklmnopqrst (20)

/(.{15})/I
Capturing subpattern count = 1
Subject length lower bound = 15
    abcdefghijklmnopqrstuvwxyz
 0: abcdefghijklmno
 1: abcdefghijklmno
    abcdefghijklmnopqrstuvwxyz\=copy=1,get=1
 0: abcdefghijklmno
 1: abcdefghijklmno
 1C abcdefghijklmno (15)
 1G abcdefghijklmno (15)

/(.{16})/I
Capturing subpattern count = 1
Subject length lower bound = 16
    abcdefghijklmnopqrstuvwxyz
 0: abcdefghijklmnop
 1: abcdefghijklmnop
    abcdefghijklmnopqrstuvwxyz\=copy=1,get=1,getall
 0: abcdefghijklmnop
 1: abcdefghijklmnop
 1C abcdefghijklmnop (16)
 1G abcdefghijklmnop (16)
 0L abcdefghijklmnop
 1L abcdefghijklmnop

/^(a|(bc))de(f)/I
Capturing subpattern count = 3
Compile options: <none>
Overall options: anchored
Subject length lower bound = 4
    adef\=get=1,get=2,get=3,get=4,getall
 0: adef
 1: a
 2: <unset>
 3: f
 1G a (1)
get substring 2 failed (-47): unknown or unset substring
 3G f (1)
get substring 4 failed (-47): unknown or unset substring
 0L adef
 1L a
 2L 
 3L f
    bcdef\=get=1,get=2,get=3,get=4,getall
 0: bcdef
 1: bc
 2: bc
 3: f
 1G bc (2)
 2G bc (2)
 3G f (1)
get substring 4 failed (-47): unknown or unset substring
 0L bcdef
 1L bc
 2L bc
 3L f
    adefghijk\=copy=0
 0: adef
 1: a
 2: <unset>
 3: f
 0C adef (4)

/^abc\00def/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 7
    abc\00def\=copy=0,getall
 0: abc\x00def
 0C abc\x00def (7)
 0L abc\x00def

/word ((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+
)((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+
)?)?)?)?)?)?)?)?)?otherword/I
Capturing subpattern count = 8
Contains explicit CR or LF match
First code unit = 'w'
Last code unit = 'd'
Subject length lower bound = 14

/.*X/IB
------------------------------------------------------------------
        Bra
        Any*
        X
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit at start or follows newline
Last code unit = 'X'
Subject length lower bound = 1

/.*X/IBs
------------------------------------------------------------------
        Bra
        AllAny*
        X
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: dotall
Overall options: anchored dotall
Last code unit = 'X'
Subject length lower bound = 1

/(.*X|^B)/IB
------------------------------------------------------------------
        Bra
        CBra 1
        Any*
        X
        Alt
        ^
        B
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
First code unit at start or follows newline
Subject length lower bound = 1

/(.*X|^B)/IBs
------------------------------------------------------------------
        Bra
        CBra 1
        AllAny*
        X
        Alt
        ^
        B
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Compile options: dotall
Overall options: anchored dotall
Subject length lower bound = 1

/(?s)(.*X|^B)/IB
------------------------------------------------------------------
        Bra
        CBra 1
        AllAny*
        X
        Alt
        ^
        B
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored dotall
Subject length lower bound = 1

/(?s:.*X|^B)/IB
------------------------------------------------------------------
        Bra
        Bra
        AllAny*
        X
        Alt
        ^
        B
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/\Biss\B/I,aftertext
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = 'i'
Last code unit = 's'
Subject length lower bound = 3
    Mississippi
 0: iss
 0+ issippi

/iss/I,aftertext,altglobal
Capturing subpattern count = 0
First code unit = 'i'
Last code unit = 's'
Subject length lower bound = 3
    Mississippi
 0: iss
 0+ issippi
 0: iss
 0+ ippi

/\Biss\B/I,aftertext,altglobal
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = 'i'
Last code unit = 's'
Subject length lower bound = 3
    Mississippi
 0: iss
 0+ issippi

/\Biss\B/Ig,aftertext
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = 'i'
Last code unit = 's'
Subject length lower bound = 3
    Mississippi
 0: iss
 0+ issippi
 0: iss
 0+ ippi
    *** Failers
No match
    Mississippi\=anchored
No match

/(?<=[Ms])iss/Ig,aftertext
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = 'i'
Last code unit = 's'
Subject length lower bound = 3
    Mississippi
 0: iss
 0+ issippi
 0: iss
 0+ ippi

/(?<=[Ms])iss/I,aftertext,altglobal
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = 'i'
Last code unit = 's'
Subject length lower bound = 3
    Mississippi
 0: iss
 0+ issippi

/^iss/Ig,aftertext
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3
    ississippi
 0: iss
 0+ issippi

/.*iss/Ig,aftertext
Capturing subpattern count = 0
First code unit at start or follows newline
Last code unit = 's'
Subject length lower bound = 3
    abciss\nxyzisspqr
 0: abciss
 0+ \x0axyzisspqr
 0: xyziss
 0+ pqr

/.i./Ig,aftertext
Capturing subpattern count = 0
Last code unit = 'i'
Subject length lower bound = 3
    Mississippi
 0: Mis
 0+ sissippi
 0: sis
 0+ sippi
 0: sip
 0+ pi
    Mississippi\=anchored
 0: Mis
 0+ sissippi
 0: sis
 0+ sippi
 0: sip
 0+ pi
    Missouri river
 0: Mis
 0+ souri river
 0: ri 
 0+ river
 0: riv
 0+ er
    Missouri river\=anchored
 0: Mis
 0+ souri river

/^.is/Ig,aftertext
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3
    Mississippi
 0: Mis
 0+ sissippi

/^ab\n/Ig,aftertext
Capturing subpattern count = 0
Contains explicit CR or LF match
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3
    ab\nab\ncd
 0: ab\x0a
 0+ ab\x0acd

/^ab\n/Igm,aftertext
Capturing subpattern count = 0
Contains explicit CR or LF match
Options: multiline
First code unit at start or follows newline
Last code unit = \x0a
Subject length lower bound = 3
    ab\nab\ncd
 0: ab\x0a
 0+ ab\x0acd
 0: ab\x0a
 0+ cd

/abc/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3

/abc|bac/I
Capturing subpattern count = 0
Starting code units: a b 
Last code unit = 'c'
Subject length lower bound = 3

/(abc|bac)/I
Capturing subpattern count = 1
Starting code units: a b 
Last code unit = 'c'
Subject length lower bound = 3

/(abc|(c|dc))/I
Capturing subpattern count = 2
Starting code units: a c d 
Last code unit = 'c'
Subject length lower bound = 1

/(abc|(d|de)c)/I
Capturing subpattern count = 2
Starting code units: a d 
Last code unit = 'c'
Subject length lower bound = 2

/a*/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0

/a+/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1

/(baa|a+)/I
Capturing subpattern count = 1
Starting code units: a b 
Last code unit = 'a'
Subject length lower bound = 1

/a{0,3}/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0

/baa{3,}/I
Capturing subpattern count = 0
First code unit = 'b'
Last code unit = 'a'
Subject length lower bound = 5

/"([^\\"]+|\\.)*"/I
Capturing subpattern count = 1
First code unit = '"'
Last code unit = '"'
Subject length lower bound = 2

/(abc|ab[cd])/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 3

/(a|.)/I
Capturing subpattern count = 1
Subject length lower bound = 1

/a|ba|\w/I
Capturing subpattern count = 0
Starting code units: 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P 
  Q R S T U V W X Y Z _ a b c d e f g h i j k l m n o p q r s t u v w x y z 
Subject length lower bound = 1

/abc(?=pqr)/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'r'
Subject length lower bound = 3

/...(?<=abc)/I
Capturing subpattern count = 0
Max lookbehind = 3
Subject length lower bound = 3

/abc(?!pqr)/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3

/ab./I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3

/ab[xyz]/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3

/abc*/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/ab.c*/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3

/a.c*/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 2

/.c*/I
Capturing subpattern count = 0
Subject length lower bound = 1

/ac*/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1

/(a.c*|b.c*)/I
Capturing subpattern count = 1
Starting code units: a b 
Subject length lower bound = 2

/a.c*|aba/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 2

/.+a/I
Capturing subpattern count = 0
Last code unit = 'a'
Subject length lower bound = 2

/(?=abcda)a.*/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'a'
Subject length lower bound = 1

/(?=a)a.*/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1

/a(b)*/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 1

/a\d*/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1

/ab\d*/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/a(\d)*/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 1

/abcde{0,0}/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'd'
Subject length lower bound = 4

/ab\d+/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3

/a(?(1)b)(.)/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 2

/a(?(1)bag|big)(.)/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'g'
Subject length lower bound = 5

/a(?(1)bag|big)*(.)/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 2

/a(?(1)bag|big)+(.)/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'g'
Subject length lower bound = 5

/a(?(1)b..|b..)(.)/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 5

/ab\d{0}e/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'e'
Subject length lower bound = 3

/a?b?/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    a
 0: a
    b
 0: b
    ab
 0: ab
    \
 0: 
    *** Failers
 0: 
    \=notempty
No match

/|-/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    abcd
 0: 
    -abc
 0: 
    ab-c\=notempty
 0: -
    *** Failers
 0: 
    abc\=notempty
No match

/^.?abcd/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Last code unit = 'd'
Subject length lower bound = 4

/\(             # ( at start
  (?:           # Non-capturing bracket
  (?>[^()]+)    # Either a sequence of non-brackets (no backtracking)
  |             # Or
  (?R)          # Recurse - i.e. nested bracketed string
  )*            # Zero or more contents
  \)            # Closing )
  /Ix
Capturing subpattern count = 0
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (abcd)
 0: (abcd)
    (abcd)xyz
 0: (abcd)
    xyz(abcd)
 0: (abcd)
    (ab(xy)cd)pqr
 0: (ab(xy)cd)
    (ab(xycd)pqr
 0: (xycd)
    () abc ()
 0: ()
    12(abcde(fsh)xyz(foo(bar))lmno)89
 0: (abcde(fsh)xyz(foo(bar))lmno)
    *** Failers
No match
    abcd
No match
    abcd)
No match
    (abcd
No match

/\(  ( (?>[^()]+) | (?R) )* \) /Igx
Capturing subpattern count = 1
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (ab(xy)cd)pqr
 0: (ab(xy)cd)
 1: cd
    1(abcd)(x(y)z)pqr
 0: (abcd)
 1: abcd
 0: (x(y)z)
 1: z

/\(  (?: (?>[^()]+) | (?R) ) \) /Ix
Capturing subpattern count = 0
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 3
    (abcd)
 0: (abcd)
    (ab(xy)cd)
 0: (xy)
    (a(b(c)d)e)
 0: (c)
    ((ab))
 0: ((ab))
    *** Failers
No match
    ()
No match

/\(  (?: (?>[^()]+) | (?R) )? \) /Ix
Capturing subpattern count = 0
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    ()
 0: ()
    12(abcde(fsh)xyz(foo(bar))lmno)89
 0: (fsh)

/\(  ( (?>[^()]+) | (?R) )* \) /Ix
Capturing subpattern count = 1
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (ab(xy)cd)
 0: (ab(xy)cd)
 1: cd

/\( ( ( (?>[^()]+) | (?R) )* ) \) /Ix
Capturing subpattern count = 2
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (ab(xy)cd)
 0: (ab(xy)cd)
 1: ab(xy)cd
 2: cd

/\( (123)? ( ( (?>[^()]+) | (?R) )* ) \) /Ix
Capturing subpattern count = 3
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (ab(xy)cd)
 0: (ab(xy)cd)
 1: <unset>
 2: ab(xy)cd
 3: cd
    (123ab(xy)cd)
 0: (123ab(xy)cd)
 1: 123
 2: ab(xy)cd
 3: cd

/\( ( (123)? ( (?>[^()]+) | (?R) )* ) \) /Ix
Capturing subpattern count = 3
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (ab(xy)cd)
 0: (ab(xy)cd)
 1: ab(xy)cd
 2: <unset>
 3: cd
    (123ab(xy)cd)
 0: (123ab(xy)cd)
 1: 123ab(xy)cd
 2: 123
 3: cd

/\( (((((((((( ( (?>[^()]+) | (?R) )* )))))))))) \) /Ix
Capturing subpattern count = 11
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (ab(xy)cd)
 0: (ab(xy)cd)
 1: ab(xy)cd
 2: ab(xy)cd
 3: ab(xy)cd
 4: ab(xy)cd
 5: ab(xy)cd
 6: ab(xy)cd
 7: ab(xy)cd
 8: ab(xy)cd
 9: ab(xy)cd
10: ab(xy)cd
11: cd

/\( ( ( (?>[^()<>]+) | ((?>[^()]+)) | (?R) )* ) \) /Ix
Capturing subpattern count = 3
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (abcd(xyz<p>qrs)123)
 0: (abcd(xyz<p>qrs)123)
 1: abcd(xyz<p>qrs)123
 2: 123

/\( ( ( (?>[^()]+) | ((?R)) )* ) \) /Ix
Capturing subpattern count = 3
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (ab(cd)ef)
 0: (ab(cd)ef)
 1: ab(cd)ef
 2: ef
 3: (cd)
    (ab(cd(ef)gh)ij)
 0: (ab(cd(ef)gh)ij)
 1: ab(cd(ef)gh)ij
 2: ij
 3: (cd(ef)gh)

/^[[:alnum:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [0-9A-Za-z]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:^alnum:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x00-/:-@[-`{-\xff] (neg)
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:alpha:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [A-Za-z]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:^alpha:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x00-@[-`{-\xff] (neg)
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/[_[:alpha:]]/I
Capturing subpattern count = 0
Starting code units: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 
  _ a b c d e f g h i j k l m n o p q r s t u v w x y z 
Subject length lower bound = 1

/^[[:ascii:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x00-\x7f]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:^ascii:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x80-\xff] (neg)
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:blank:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x09 ]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:^blank:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x00-\x08\x0a-\x1f!-\xff] (neg)
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/[\n\x0b\x0c\x0d[:blank:]]/I
Capturing subpattern count = 0
Contains explicit CR or LF match
Starting code units: \x09 \x0a \x0b \x0c \x0d \x20 
Subject length lower bound = 1

/^[[:cntrl:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x00-\x1f\x7f]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:digit:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [0-9]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:graph:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [!-~]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:lower:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [a-z]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:print:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [ -~]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:punct:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [!-/:-@[-`{-~]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:space:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x09-\x0d ]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:upper:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [A-Z]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:xdigit:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [0-9A-Fa-f]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:word:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [0-9A-Z_a-z]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:^cntrl:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [ -~\x80-\xff] (neg)
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[12[:^digit:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x00-/12:-\xff] (neg)
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:^blank:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x00-\x08\x0a-\x1f!-\xff] (neg)
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/[01[:alpha:]%]/IB
------------------------------------------------------------------
        Bra
        [%01A-Za-z]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: % 0 1 A B C D E F G H I J K L M N O P Q R S T U V W 
  X Y Z a b c d e f g h i j k l m n o p q r s t u v w x y z 
Subject length lower bound = 1

/[[.ch.]]/I
Failed: error 113 at offset 1: POSIX collating elements are not supported

/[[=ch=]]/I
Failed: error 113 at offset 1: POSIX collating elements are not supported

/[[:rhubarb:]]/I
Failed: error 130 at offset 3: unknown POSIX class name

/[[:upper:]]/Ii
Capturing subpattern count = 0
Options: caseless
Starting code units: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 
  a b c d e f g h i j k l m n o p q r s t u v w x y z 
Subject length lower bound = 1
    A
 0: A
    a
 0: a

/[[:lower:]]/Ii
Capturing subpattern count = 0
Options: caseless
Starting code units: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 
  a b c d e f g h i j k l m n o p q r s t u v w x y z 
Subject length lower bound = 1
    A
 0: A
    a
 0: a

/((?-i)[[:lower:]])[[:lower:]]/Ii
Capturing subpattern count = 1
Options: caseless
Starting code units: a b c d e f g h i j k l m n o p q r s t u v w x y z 
Subject length lower bound = 2
    ab
 0: ab
 1: a
    aB
 0: aB
 1: a
    *** Failers
 0: ai
 1: a
    Ab
No match
    AB
No match

/[\200-\110]/I
Failed: error 108 at offset 9: range out of order in character class

/^(?(0)f|b)oo/I
Failed: error 135 at offset 6: invalid condition (?(0)

# This one's here because of the large output vector needed

/(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\w+)\s+(\270)/I
Capturing subpattern count = 271
Max back reference = 270
Starting code units: 0 1 2 3 4 5 6 7 8 9 
Subject length lower bound = 272
     1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 ABC ABC\=ovector=300
 0: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 ABC ABC
 1: 1 
 2: 2 
 3: 3 
 4: 4 
 5: 5 
 6: 6 
 7: 7 
 8: 8 
 9: 9 
10: 10 
11: 11 
12: 12 
13: 13 
14: 14 
15: 15 
16: 16 
17: 17 
18: 18 
19: 19 
20: 20 
21: 21 
22: 22 
23: 23 
24: 24 
25: 25 
26: 26 
27: 27 
28: 28 
29: 29 
30: 30 
31: 31 
32: 32 
33: 33 
34: 34 
35: 35 
36: 36 
37: 37 
38: 38 
39: 39 
40: 40 
41: 41 
42: 42 
43: 43 
44: 44 
45: 45 
46: 46 
47: 47 
48: 48 
49: 49 
50: 50 
51: 51 
52: 52 
53: 53 
54: 54 
55: 55 
56: 56 
57: 57 
58: 58 
59: 59 
60: 60 
61: 61 
62: 62 
63: 63 
64: 64 
65: 65 
66: 66 
67: 67 
68: 68 
69: 69 
70: 70 
71: 71 
72: 72 
73: 73 
74: 74 
75: 75 
76: 76 
77: 77 
78: 78 
79: 79 
80: 80 
81: 81 
82: 82 
83: 83 
84: 84 
85: 85 
86: 86 
87: 87 
88: 88 
89: 89 
90: 90 
91: 91 
92: 92 
93: 93 
94: 94 
95: 95 
96: 96 
97: 97 
98: 98 
99: 99 
100: 100 
101: 101 
102: 102 
103: 103 
104: 104 
105: 105 
106: 106 
107: 107 
108: 108 
109: 109 
110: 110 
111: 111 
112: 112 
113: 113 
114: 114 
115: 115 
116: 116 
117: 117 
118: 118 
119: 119 
120: 120 
121: 121 
122: 122 
123: 123 
124: 124 
125: 125 
126: 126 
127: 127 
128: 128 
129: 129 
130: 130 
131: 131 
132: 132 
133: 133 
134: 134 
135: 135 
136: 136 
137: 137 
138: 138 
139: 139 
140: 140 
141: 141 
142: 142 
143: 143 
144: 144 
145: 145 
146: 146 
147: 147 
148: 148 
149: 149 
150: 150 
151: 151 
152: 152 
153: 153 
154: 154 
155: 155 
156: 156 
157: 157 
158: 158 
159: 159 
160: 160 
161: 161 
162: 162 
163: 163 
164: 164 
165: 165 
166: 166 
167: 167 
168: 168 
169: 169 
170: 170 
171: 171 
172: 172 
173: 173 
174: 174 
175: 175 
176: 176 
177: 177 
178: 178 
179: 179 
180: 180 
181: 181 
182: 182 
183: 183 
184: 184 
185: 185 
186: 186 
187: 187 
188: 188 
189: 189 
190: 190 
191: 191 
192: 192 
193: 193 
194: 194 
195: 195 
196: 196 
197: 197 
198: 198 
199: 199 
200: 200 
201: 201 
202: 202 
203: 203 
204: 204 
205: 205 
206: 206 
207: 207 
208: 208 
209: 209 
210: 210 
211: 211 
212: 212 
213: 213 
214: 214 
215: 215 
216: 216 
217: 217 
218: 218 
219: 219 
220: 220 
221: 221 
222: 222 
223: 223 
224: 224 
225: 225 
226: 226 
227: 227 
228: 228 
229: 229 
230: 230 
231: 231 
232: 232 
233: 233 
234: 234 
235: 235 
236: 236 
237: 237 
238: 238 
239: 239 
240: 240 
241: 241 
242: 242 
243: 243 
244: 244 
245: 245 
246: 246 
247: 247 
248: 248 
249: 249 
250: 250 
251: 251 
252: 252 
253: 253 
254: 254 
255: 255 
256: 256 
257: 257 
258: 258 
259: 259 
260: 260 
261: 261 
262: 262 
263: 263 
264: 264 
265: 265 
266: 266 
267: 267 
268: 268 
269: 269 
270: ABC
271: ABC

# This one's here because Perl does this differently and PCRE2 can't at present

/(main(O)?)+/I
Capturing subpattern count = 2
First code unit = 'm'
Last code unit = 'n'
Subject length lower bound = 4
    mainmain
 0: mainmain
 1: main
    mainOmain
 0: mainOmain
 1: main
 2: O

# These are all cases where Perl does it differently (nested captures)

/^(a(b)?)+$/I
Capturing subpattern count = 2
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1
    aba
 0: aba
 1: a
 2: b

/^(aa(bb)?)+$/I
Capturing subpattern count = 2
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbaa
 0: aabbaa
 1: aa
 2: bb

/^(aa|aa(bb))+$/I
Capturing subpattern count = 2
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbaa
 0: aabbaa
 1: aa
 2: bb

/^(aa(bb)??)+$/I
Capturing subpattern count = 2
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbaa
 0: aabbaa
 1: aa
 2: bb

/^(?:aa(bb)?)+$/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbaa
 0: aabbaa
 1: bb

/^(aa(b(b))?)+$/I
Capturing subpattern count = 3
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbaa
 0: aabbaa
 1: aa
 2: bb
 3: b

/^(?:aa(b(b))?)+$/I
Capturing subpattern count = 2
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbaa
 0: aabbaa
 1: bb
 2: b

/^(?:aa(b(?:b))?)+$/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbaa
 0: aabbaa
 1: bb

/^(?:aa(bb(?:b))?)+$/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbbaa
 0: aabbbaa
 1: bbb

/^(?:aa(b(?:bb))?)+$/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbbaa
 0: aabbbaa
 1: bbb

/^(?:aa(?:b(b))?)+$/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbaa
 0: aabbaa
 1: b

/^(?:aa(?:b(bb))?)+$/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbbaa
 0: aabbbaa
 1: bb

/^(aa(b(bb))?)+$/I
Capturing subpattern count = 3
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbbaa
 0: aabbbaa
 1: aa
 2: bbb
 3: bb

/^(aa(bb(bb))?)+$/I
Capturing subpattern count = 3
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbbbaa
 0: aabbbbaa
 1: aa
 2: bbbb
 3: bb

# ----------------

/#/IBx
------------------------------------------------------------------
        Bra
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
May match empty string
Options: extended
Subject length lower bound = 0

/a#/IBx
------------------------------------------------------------------
        Bra
        a
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: extended
First code unit = 'a'
Subject length lower bound = 1

/[\s]/IB
------------------------------------------------------------------
        Bra
        [\x09-\x0d ]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: \x09 \x0a \x0b \x0c \x0d \x20 
Subject length lower bound = 1

/[\S]/IB
------------------------------------------------------------------
        Bra
        [\x00-\x08\x0e-\x1f!-\xff] (neg)
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: \x00 \x01 \x02 \x03 \x04 \x05 \x06 \x07 \x08 \x0e \x0f 
  \x10 \x11 \x12 \x13 \x14 \x15 \x16 \x17 \x18 \x19 \x1a \x1b \x1c \x1d \x1e 
  \x1f ! " # $ % & ' ( ) * + , - . / 0 1 2 3 4 5 6 7 8 9 : ; < = > ? @ A B C 
  D E F G H I J K L M N O P Q R S T U V W X Y Z [ \ ] ^ _ ` a b c d e f g h 
  i j k l m n o p q r s t u v w x y z { | } ~ \x7f \x80 \x81 \x82 \x83 \x84 
  \x85 \x86 \x87 \x88 \x89 \x8a \x8b \x8c \x8d \x8e \x8f \x90 \x91 \x92 \x93 
  \x94 \x95 \x96 \x97 \x98 \x99 \x9a \x9b \x9c \x9d \x9e \x9f \xa0 \xa1 \xa2 
  \xa3 \xa4 \xa5 \xa6 \xa7 \xa8 \xa9 \xaa \xab \xac \xad \xae \xaf \xb0 \xb1 
  \xb2 \xb3 \xb4 \xb5 \xb6 \xb7 \xb8 \xb9 \xba \xbb \xbc \xbd \xbe \xbf \xc0 
  \xc1 \xc2 \xc3 \xc4 \xc5 \xc6 \xc7 \xc8 \xc9 \xca \xcb \xcc \xcd \xce \xcf 
  \xd0 \xd1 \xd2 \xd3 \xd4 \xd5 \xd6 \xd7 \xd8 \xd9 \xda \xdb \xdc \xdd \xde 
  \xdf \xe0 \xe1 \xe2 \xe3 \xe4 \xe5 \xe6 \xe7 \xe8 \xe9 \xea \xeb \xec \xed 
  \xee \xef \xf0 \xf1 \xf2 \xf3 \xf4 \xf5 \xf6 \xf7 \xf8 \xf9 \xfa \xfb \xfc 
  \xfd \xfe \xff 
Subject length lower bound = 1

/a(?i)b/IB
------------------------------------------------------------------
        Bra
        a
     /i b
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b' (caseless)
Subject length lower bound = 2
    ab
 0: ab
    aB
 0: aB
    *** Failers
No match
    AB
No match

/(a(?i)b)/IB
------------------------------------------------------------------
        Bra
        CBra 1
        a
     /i b
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'b' (caseless)
Subject length lower bound = 2
    ab
 0: ab
 1: ab
    aB
 0: aB
 1: aB
    *** Failers
No match
    AB
No match

/   (?i)abc/IBx
------------------------------------------------------------------
        Bra
     /i abc
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: extended
Overall options: caseless extended
First code unit = 'a' (caseless)
Last code unit = 'c' (caseless)
Subject length lower bound = 3

/#this is a comment
  (?i)abc/IBx
------------------------------------------------------------------
        Bra
     /i abc
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: extended
Overall options: caseless extended
First code unit = 'a' (caseless)
Last code unit = 'c' (caseless)
Subject length lower bound = 3

/123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890/IB
------------------------------------------------------------------
        Bra
        123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = '1'
Last code unit = '0'
Subject length lower bound = 300

/\Q123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890/IB
------------------------------------------------------------------
        Bra
        123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = '1'
Last code unit = '0'
Subject length lower bound = 300

/\Q\E/IB
------------------------------------------------------------------
        Bra
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    \
 0: 

/\Q\Ex/IB
------------------------------------------------------------------
        Bra
        x
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = 'x'
Subject length lower bound = 1

/ \Q\E/IB
------------------------------------------------------------------
        Bra
         
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = ' '
Subject length lower bound = 1

/a\Q\E/IB
------------------------------------------------------------------
        Bra
        a
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1
  abc
 0: a
  bca
 0: a
  bac
 0: a

/a\Q\Eb/IB
------------------------------------------------------------------
        Bra
        ab
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
  abc
 0: ab

/\Q\Eabc/IB
------------------------------------------------------------------
        Bra
        abc
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3

/x*+\w/IB
------------------------------------------------------------------
        Bra
        x*+
        \w
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P 
  Q R S T U V W X Y Z _ a b c d e f g h i j k l m n o p q r s t u v w x y z 
Subject length lower bound = 1
    *** Failers
 0: F
    xxxxx
No match

/x?+/IB
------------------------------------------------------------------
        Bra
        x?+
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0

/x++/IB
------------------------------------------------------------------
        Bra
        x++
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = 'x'
Subject length lower bound = 1

/x{1,3}+/B,no_auto_possess
------------------------------------------------------------------
        Bra
        x
        x{0,2}+
        Ket
        End
------------------------------------------------------------------

/x{1,3}+/Bi,no_auto_possess
------------------------------------------------------------------
        Bra
     /i x
     /i x{0,2}+
        Ket
        End
------------------------------------------------------------------

/[^x]{1,3}+/B,no_auto_possess
------------------------------------------------------------------
        Bra
        [^x]
        [^x]{0,2}+
        Ket
        End
------------------------------------------------------------------

/[^x]{1,3}+/Bi,no_auto_possess
------------------------------------------------------------------
        Bra
     /i [^x]
     /i [^x]{0,2}+
        Ket
        End
------------------------------------------------------------------

/(x)*+/IB
------------------------------------------------------------------
        Bra
        Braposzero
        CBraPos 1
        x
        KetRpos
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
May match empty string
Subject length lower bound = 0

/^(\w++|\s++)*$/I
Capturing subpattern count = 1
May match empty string
Compile options: <none>
Overall options: anchored
Subject length lower bound = 0
    now is the time for all good men to come to the aid of the party
 0: now is the time for all good men to come to the aid of the party
 1: party
    *** Failers
No match
    this is not a line with only words and spaces!
No match

/(\d++)(\w)/I
Capturing subpattern count = 2
Starting code units: 0 1 2 3 4 5 6 7 8 9 
Subject length lower bound = 2
    12345a
 0: 12345a
 1: 12345
 2: a
    *** Failers
No match
    12345+
No match

/a++b/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
    aaab
 0: aaab

/(a++b)/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
    aaab
 0: aaab
 1: aaab

/(a++)b/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
    aaab
 0: aaab
 1: aaa

/([^()]++|\([^()]*\))+/I
Capturing subpattern count = 1
Starting code units: \x00 \x01 \x02 \x03 \x04 \x05 \x06 \x07 \x08 \x09 \x0a 
  \x0b \x0c \x0d \x0e \x0f \x10 \x11 \x12 \x13 \x14 \x15 \x16 \x17 \x18 \x19 
  \x1a \x1b \x1c \x1d \x1e \x1f \x20 ! " # $ % & ' ( * + , - . / 0 1 2 3 4 5 
  6 7 8 9 : ; < = > ? @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 
  [ \ ] ^ _ ` a b c d e f g h i j k l m n o p q r s t u v w x y z { | } ~ \x7f 
  \x80 \x81 \x82 \x83 \x84 \x85 \x86 \x87 \x88 \x89 \x8a \x8b \x8c \x8d \x8e 
  \x8f \x90 \x91 \x92 \x93 \x94 \x95 \x96 \x97 \x98 \x99 \x9a \x9b \x9c \x9d 
  \x9e \x9f \xa0 \xa1 \xa2 \xa3 \xa4 \xa5 \xa6 \xa7 \xa8 \xa9 \xaa \xab \xac 
  \xad \xae \xaf \xb0 \xb1 \xb2 \xb3 \xb4 \xb5 \xb6 \xb7 \xb8 \xb9 \xba \xbb 
  \xbc \xbd \xbe \xbf \xc0 \xc1 \xc2 \xc3 \xc4 \xc5 \xc6 \xc7 \xc8 \xc9 \xca 
  \xcb \xcc \xcd \xce \xcf \xd0 \xd1 \xd2 \xd3 \xd4 \xd5 \xd6 \xd7 \xd8 \xd9 
  \xda \xdb \xdc \xdd \xde \xdf \xe0 \xe1 \xe2 \xe3 \xe4 \xe5 \xe6 \xe7 \xe8 
  \xe9 \xea \xeb \xec \xed \xee \xef \xf0 \xf1 \xf2 \xf3 \xf4 \xf5 \xf6 \xf7 
  \xf8 \xf9 \xfa \xfb \xfc \xfd \xfe \xff 
Subject length lower bound = 1
    ((abc(ade)ufh()()x
 0: abc(ade)ufh()()x
 1: x

/\(([^()]++|\([^()]+\))+\)/I
Capturing subpattern count = 1
First code unit = '('
Last code unit = ')'
Subject length lower bound = 3
    (abc)
 0: (abc)
 1: abc
    (abc(def)xyz)
 0: (abc(def)xyz)
 1: xyz
    *** Failers
No match
    ((()aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
No match

/(abc){1,3}+/IB
------------------------------------------------------------------
        Bra
        Once
        CBra 1
        abc
        Ket
        Brazero
        Bra
        CBra 1
        abc
        Ket
        Brazero
        CBra 1
        abc
        Ket
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3

/a+?+/I
Failed: error 109 at offset 3: nothing to repeat

/a{2,3}?+b/I
Failed: error 109 at offset 7: nothing to repeat

/(?U)a+?+/I
Failed: error 109 at offset 7: nothing to repeat

/a{2,3}?+b/I,ungreedy
Failed: error 109 at offset 7: nothing to repeat

/x(?U)a++b/IB
------------------------------------------------------------------
        Bra
        x
        a++
        b
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = 'x'
Last code unit = 'b'
Subject length lower bound = 3
    xaaaab
 0: xaaaab

/(?U)xa++b/IB
------------------------------------------------------------------
        Bra
        x
        a++
        b
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: ungreedy
First code unit = 'x'
Last code unit = 'b'
Subject length lower bound = 3
    xaaaab
 0: xaaaab

/^((a+)(?U)([ab]+)(?-U)([bc]+)(\w*))/IB
------------------------------------------------------------------
        Bra
        ^
        CBra 1
        CBra 2
        a+
        Ket
        CBra 3
        [ab]+?
        Ket
        CBra 4
        [bc]+
        Ket
        CBra 5
        \w*+
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 5
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3

/^x(?U)a+b/IB
------------------------------------------------------------------
        Bra
        ^
        x
        a++
        b
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Last code unit = 'b'
Subject length lower bound = 3

/^x(?U)(a+)b/IB
------------------------------------------------------------------
        Bra
        ^
        x
        CBra 1
        a+?
        Ket
        b
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Last code unit = 'b'
Subject length lower bound = 3

/[.x.]/I
Failed: error 113 at offset 0: POSIX collating elements are not supported

/[=x=]/I
Failed: error 113 at offset 0: POSIX collating elements are not supported

/[:x:]/I
Failed: error 112 at offset 0: POSIX named classes are supported only within a class

/\l/I
Failed: error 137 at offset 1: PCRE does not support \L, \l, \N{name}, \U, or \u

/\L/I
Failed: error 137 at offset 1: PCRE does not support \L, \l, \N{name}, \U, or \u

/\N{name}/I
Failed: error 137 at offset 1: PCRE does not support \L, \l, \N{name}, \U, or \u

/\u/I
Failed: error 137 at offset 1: PCRE does not support \L, \l, \N{name}, \U, or \u

/\U/I
Failed: error 137 at offset 1: PCRE does not support \L, \l, \N{name}, \U, or \u

/a{1,3}b/ungreedy
    ab
 0: ab

/[/I
Failed: error 106 at offset 1: missing terminating ] for character class

/[a-/I
Failed: error 106 at offset 3: missing terminating ] for character class

/[[:space:]/I
Failed: error 106 at offset 10: missing terminating ] for character class

/[\s]/IB
------------------------------------------------------------------
        Bra
        [\x09-\x0d ]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: \x09 \x0a \x0b \x0c \x0d \x20 
Subject length lower bound = 1

/[[:space:]]/IB
------------------------------------------------------------------
        Bra
        [\x09-\x0d ]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: \x09 \x0a \x0b \x0c \x0d \x20 
Subject length lower bound = 1

/[[:space:]abcde]/IB
------------------------------------------------------------------
        Bra
        [\x09-\x0d a-e]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: \x09 \x0a \x0b \x0c \x0d \x20 a b c d e 
Subject length lower bound = 1

/< (?: (?(R) \d++  | [^<>]*+) | (?R)) * >/Ix
Capturing subpattern count = 0
Options: extended
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 2
    <>
 0: <>
    <abcd>
 0: <abcd>
    <abc <123> hij>
 0: <abc <123> hij>
    <abc <def> hij>
 0: <def>
    <abc<>def>
 0: <abc<>def>
    <abc<>
 0: <>
    *** Failers
No match
    <abc
No match

/8J\$WE\<\.rX\+ix\[d1b\!H\#\?vV0vrK\:ZH1\=2M\>iV\;\?aPhFB\<\*vW\@QW\@sO9\}cfZA\-i\'w\%hKd6gt1UJP\,15_\#QY\$M\^Mss_U\/\]\&LK9\[5vQub\^w\[KDD\<EjmhUZ\?\.akp2dF\>qmj\;2\}YWFdYx\.Ap\]hjCPTP\(n28k\+3\;o\&WXqs\/gOXdr\$\:r\'do0\;b4c\(f_Gr\=\"\\4\)\[01T7ajQJvL\$W\~mL_sS\/4h\:x\*\[ZN\=KLs\&L5zX\/\/\>it\,o\:aU\(\;Z\>pW\&T7oP\'2K\^E\:x9\'c\[\%z\-\,64JQ5AeH_G\#KijUKghQw\^\\vea3a\?kka_G\$8\#\`\*kynsxzBLru\'\]k_\[7FrVx\}\^\=\$blx\>s\-N\%j\;D\*aZDnsw\:YKZ\%Q\.Kne9\#hP\?\+b3\(SOvL\,\^\;\&u5\@\?5C5Bhb\=m\-vEh_L15Jl\]U\)0RP6\{q\%L\^_z5E\'Dw6X\b/IB
------------------------------------------------------------------
        Bra
        8J$WE<.rX+ix[d1b!H#?vV0vrK:ZH1=2M>iV;?aPhFB<*vW@QW@sO9}cfZA-i'w%hKd6gt1UJP,15_#QY$M^Mss_U/]&LK9[5vQub^w[KDD<EjmhUZ?.akp2dF>qmj;2}YWFdYx.Ap]hjCPTP(n28k+3;o&WXqs/gOXdr$:r'do0;b4c(f_Gr="\4)[01T7ajQJvL$W~mL_sS/4h:x*[ZN=KLs&L5zX//>it,o:aU(;Z>pW&T7oP'2K^E:x9'c[%z-,64JQ5AeH_G#KijUKghQw^\vea3a?kka_G$8#`*kynsxzBLru']k_[7FrVx}^=$blx>s-N%j;D*aZDnsw:YKZ%Q.Kne9#hP?+b3(SOvL,^;&u5@?5C5Bhb=m-vEh_L15Jl]U)0RP6{q%L^_z5E'Dw6X
        \b
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = '8'
Last code unit = 'X'
Subject length lower bound = 409

/\$\<\.X\+ix\[d1b\!H\#\?vV0vrK\:ZH1\=2M\>iV\;\?aPhFB\<\*vW\@QW\@sO9\}cfZA\-i\'w\%hKd6gt1UJP\,15_\#QY\$M\^Mss_U\/\]\&LK9\[5vQub\^w\[KDD\<EjmhUZ\?\.akp2dF\>qmj\;2\}YWFdYx\.Ap\]hjCPTP\(n28k\+3\;o\&WXqs\/gOXdr\$\:r\'do0\;b4c\(f_Gr\=\"\\4\)\[01T7ajQJvL\$W\~mL_sS\/4h\:x\*\[ZN\=KLs\&L5zX\/\/\>it\,o\:aU\(\;Z\>pW\&T7oP\'2K\^E\:x9\'c\[\%z\-\,64JQ5AeH_G\#KijUKghQw\^\\vea3a\?kka_G\$8\#\`\*kynsxzBLru\'\]k_\[7FrVx\}\^\=\$blx\>s\-N\%j\;D\*aZDnsw\:YKZ\%Q\.Kne9\#hP\?\+b3\(SOvL\,\^\;\&u5\@\?5C5Bhb\=m\-vEh_L15Jl\]U\)0RP6\{q\%L\^_z5E\'Dw6X\b/IB
------------------------------------------------------------------
        Bra
        $<.X+ix[d1b!H#?vV0vrK:ZH1=2M>iV;?aPhFB<*vW@QW@sO9}cfZA-i'w%hKd6gt1UJP,15_#QY$M^Mss_U/]&LK9[5vQub^w[KDD<EjmhUZ?.akp2dF>qmj;2}YWFdYx.Ap]hjCPTP(n28k+3;o&WXqs/gOXdr$:r'do0;b4c(f_Gr="\4)[01T7ajQJvL$W~mL_sS/4h:x*[ZN=KLs&L5zX//>it,o:aU(;Z>pW&T7oP'2K^E:x9'c[%z-,64JQ5AeH_G#KijUKghQw^\vea3a?kka_G$8#`*kynsxzBLru']k_[7FrVx}^=$blx>s-N%j;D*aZDnsw:YKZ%Q.Kne9#hP?+b3(SOvL,^;&u5@?5C5Bhb=m-vEh_L15Jl]U)0RP6{q%L^_z5E'Dw6X
        \b
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = '$'
Last code unit = 'X'
Subject length lower bound = 404

/(.*)\d+\1/I
Capturing subpattern count = 1
Max back reference = 1
Subject length lower bound = 1

/(.*)\d+/I
Capturing subpattern count = 1
First code unit at start or follows newline
Subject length lower bound = 1

/(.*)\d+\1/Is
Capturing subpattern count = 1
Max back reference = 1
Options: dotall
Subject length lower bound = 1

/(.*)\d+/Is
Capturing subpattern count = 1
Compile options: dotall
Overall options: anchored dotall
Subject length lower bound = 1

/(.*(xyz))\d+\2/I
Capturing subpattern count = 2
Max back reference = 2
First code unit at start or follows newline
Last code unit = 'z'
Subject length lower bound = 7

/((.*))\d+\1/I
Capturing subpattern count = 2
Max back reference = 1
Subject length lower bound = 1
    abc123bc
 0: bc123bc
 1: bc
 2: bc

/a[b]/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/(?=a).*/I
Capturing subpattern count = 0
May match empty string
First code unit = 'a'
Subject length lower bound = 0

/(?=abc).xyz/Ii
Capturing subpattern count = 0
Options: caseless
First code unit = 'a' (caseless)
Last code unit = 'z' (caseless)
Subject length lower bound = 4

/(?=abc)(?i).xyz/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'z' (caseless)
Subject length lower bound = 4

/(?=a)(?=b)/I
Capturing subpattern count = 0
May match empty string
First code unit = 'a'
Subject length lower bound = 0

/(?=.)a/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1

/((?=abcda)a)/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'a'
Subject length lower bound = 1

/((?=abcda)ab)/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/()a/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 1

/(?:(?=.)|(?<!x))a/I
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = 'a'
Subject length lower bound = 1

/(?(1)ab|ac)(.)/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 3

/(?(1)abz|acz)(.)/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'z'
Subject length lower bound = 4

/(?(1)abz)(.)/I
Capturing subpattern count = 1
Subject length lower bound = 1

/(?(1)abz)(1)23/I
Capturing subpattern count = 1
Last code unit = '3'
Subject length lower bound = 3

/(a)+/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 1

/(a){2,3}/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'a'
Subject length lower bound = 2

/(a)*/I
Capturing subpattern count = 1
May match empty string
Subject length lower bound = 0

/[a]/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1

/[ab]/I
Capturing subpattern count = 0
Starting code units: a b 
Subject length lower bound = 1

/[ab]/I
Capturing subpattern count = 0
Starting code units: a b 
Subject length lower bound = 1

/[^a]/I
Capturing subpattern count = 0
Subject length lower bound = 1

/\d456/I
Capturing subpattern count = 0
Starting code units: 0 1 2 3 4 5 6 7 8 9 
Last code unit = '6'
Subject length lower bound = 4

/\d456/I
Capturing subpattern count = 0
Starting code units: 0 1 2 3 4 5 6 7 8 9 
Last code unit = '6'
Subject length lower bound = 4

/a^b/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/^a/Im
Capturing subpattern count = 0
Options: multiline
First code unit at start or follows newline
Last code unit = 'a'
Subject length lower bound = 1
  abcde
 0: a
  xy\nabc
 0: a
  *** Failers
No match
  xyabc
No match

/c|abc/I
Capturing subpattern count = 0
Starting code units: a c 
Last code unit = 'c'
Subject length lower bound = 1

/(?i)[ab]/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: caseless
Starting code units: A B a b 
Subject length lower bound = 1

/[ab](?i)cd/I
Capturing subpattern count = 0
Starting code units: a b 
Last code unit = 'd' (caseless)
Subject length lower bound = 3

/abc(?C)def/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'f'
Subject length lower bound = 6
    abcdef
--->abcdef
  0 ^  ^       d
 0: abcdef
    1234abcdef
--->1234abcdef
  0     ^  ^       d
 0: abcdef
    *** Failers
No match
    abcxyz
No match
    abcxyzf
--->abcxyzf
  0 ^  ^        d
No match

/abc(?C)de(?C1)f/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'f'
Subject length lower bound = 6
    123abcdef
--->123abcdef
  0    ^  ^       d
  1    ^    ^     f
 0: abcdef

/(?C1)\dabc(?C2)def/I
Capturing subpattern count = 0
Starting code units: 0 1 2 3 4 5 6 7 8 9 
Last code unit = 'f'
Subject length lower bound = 7
    1234abcdef
--->1234abcdef
  1 ^              \d
  1  ^             \d
  1   ^            \d
  1    ^           \d
  2    ^   ^       d
 0: 4abcdef
    *** Failers
No match
    abcdef
No match

/(?C1)\dabc(?C2)def/I
Capturing subpattern count = 0
Starting code units: 0 1 2 3 4 5 6 7 8 9 
Last code unit = 'f'
Subject length lower bound = 7
    1234abcdef
--->1234abcdef
  1 ^              \d
  1  ^             \d
  1   ^            \d
  1    ^           \d
  2    ^   ^       d
 0: 4abcdef
    *** Failers
No match
    abcdef
No match

/(?C255)ab/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/(?C256)ab/I
Failed: error 138 at offset 6: number after (?C is greater than 255

/(?Cab)xx/I
Failed: error 139 at offset 3: closing parenthesis for (?C expected

/(?C12vr)x/I
Failed: error 139 at offset 5: closing parenthesis for (?C expected

/abc(?C)def/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'f'
Subject length lower bound = 6
    *** Failers
No match
    \x83\x0\x61bcdef
--->\x83\x00abcdef
  0         ^  ^       d
 0: abcdef

/(abc)(?C)de(?C1)f/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'f'
Subject length lower bound = 6
    123abcdef
--->123abcdef
  0    ^  ^       d
  1    ^    ^     f
 0: abcdef
 1: abc
    123abcdef\=callout_capture
Callout 0: last capture = 1
 0: <unset>
 1: abc
--->123abcdef
       ^  ^       d
Callout 1: last capture = 1
 0: <unset>
 1: abc
--->123abcdef
       ^    ^     f
 0: abcdef
 1: abc
    123abcdefC-\=callout_none
 0: abcdef
 1: abc
    *** Failers
No match
    123abcdef\=callout_fail=1
--->123abcdef
  0    ^  ^       d
  1    ^    ^     f
No match

/(?C0)(abc(?C1))*/I
Capturing subpattern count = 1
May match empty string
Subject length lower bound = 0
    abcabcabc
--->abcabcabc
  0 ^             (abc(?C1))*
  1 ^  ^          )
  1 ^     ^       )
  1 ^        ^    )
 0: abcabcabc
 1: abc
    abcabc\=callout_fail=1:3
--->abcabc
  0 ^          (abc(?C1))*
  1 ^  ^       )
  1 ^     ^    )
 0: abcabc
 1: abc
    *** Failers
--->*** Failers
  0 ^               (abc(?C1))*
 0: 
    abcabcabc\=callout_fail=1:3
--->abcabcabc
  0 ^             (abc(?C1))*
  1 ^  ^          )
  1 ^     ^       )
  1 ^        ^    )
 0: abcabc
 1: abc

/(\d{3}(?C))*/I
Capturing subpattern count = 1
May match empty string
Subject length lower bound = 0
    123\=callout_capture
Callout 0: last capture = 0
 0: <unset>
--->123
    ^  ^    )
 0: 123
 1: 123
    123456\=callout_capture
Callout 0: last capture = 0
 0: <unset>
--->123456
    ^  ^       )
Callout 0: last capture = 1
 0: <unset>
 1: 123
--->123456
    ^     ^    )
 0: 123456
 1: 456
    123456789\=callout_capture
Callout 0: last capture = 0
 0: <unset>
--->123456789
    ^  ^          )
Callout 0: last capture = 1
 0: <unset>
 1: 123
--->123456789
    ^     ^       )
Callout 0: last capture = 1
 0: <unset>
 1: 456
--->123456789
    ^        ^    )
 0: 123456789
 1: 789

/((xyz)(?C)p|(?C1)xyzabc)/I
Capturing subpattern count = 2
First code unit = 'x'
Subject length lower bound = 4
    xyzabc\=callout_capture
Callout 0: last capture = 2
 0: <unset>
 1: <unset>
 2: xyz
--->xyzabc
    ^  ^       p
Callout 1: last capture = 0
 0: <unset>
--->xyzabc
    ^          x
 0: xyzabc
 1: xyzabc

/(X)((xyz)(?C)p|(?C1)xyzabc)/I
Capturing subpattern count = 3
First code unit = 'X'
Last code unit = 'x'
Subject length lower bound = 5
    Xxyzabc\=callout_capture
Callout 0: last capture = 3
 0: <unset>
 1: X
 2: <unset>
 3: xyz
--->Xxyzabc
    ^   ^       p
Callout 1: last capture = 1
 0: <unset>
 1: X
--->Xxyzabc
    ^^          x
 0: Xxyzabc
 1: X
 2: xyzabc

/(?=(abc))(?C)abcdef/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'f'
Subject length lower bound = 6
    abcdef\=callout_capture
Callout 0: last capture = 1
 0: <unset>
 1: abc
--->abcdef
    ^          a
 0: abcdef
 1: abc

/(?!(abc)(?C1)d)(?C2)abcxyz/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'z'
Subject length lower bound = 6
    abcxyz\=callout_capture
Callout 1: last capture = 1
 0: <unset>
 1: abc
--->abcxyz
    ^  ^       d
Callout 2: last capture = 0
 0: <unset>
--->abcxyz
    ^          a
 0: abcxyz

/(?<=(abc)(?C))xyz/I
Capturing subpattern count = 1
Max lookbehind = 3
First code unit = 'x'
Last code unit = 'z'
Subject length lower bound = 3
   abcxyz\=callout_capture
Callout 0: last capture = 1
 0: <unset>
 1: abc
--->abcxyz
       ^       )
 0: xyz
 1: abc

/a(b+)(c*)(?C1)/I
Capturing subpattern count = 2
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
    abbbbbccc\=callout_data=1
--->abbbbbccc
  1 ^        ^    
Callout data = 1
No match

/a(b+?)(c*?)(?C1)/I
Capturing subpattern count = 2
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
    abbbbbccc\=callout_data=1
--->abbbbbccc
  1 ^ ^           
Callout data = 1
  1 ^  ^          
Callout data = 1
  1 ^   ^         
Callout data = 1
  1 ^    ^        
Callout data = 1
  1 ^     ^       
Callout data = 1
  1 ^      ^      
Callout data = 1
  1 ^       ^     
Callout data = 1
  1 ^        ^    
Callout data = 1
No match

/(?C)abc/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3

/(?C)^abc/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3

/(?C)a|b/I
Capturing subpattern count = 0
Starting code units: a b 
Subject length lower bound = 1

/(?R)/I
Failed: error 140 at offset 3: recursion could loop indefinitely

/(a|(?R))/I
Failed: error 140 at offset 6: recursion could loop indefinitely

/(ab|(bc|(de|(?R))))/I
Failed: error 140 at offset 15: recursion could loop indefinitely

/x(ab|(bc|(de|(?R))))/I
Capturing subpattern count = 3
First code unit = 'x'
Subject length lower bound = 3
    xab
 0: xab
 1: ab
    xbc
 0: xbc
 1: bc
 2: bc
    xde
 0: xde
 1: de
 2: de
 3: de
    xxab
 0: xxab
 1: xab
 2: xab
 3: xab
    xxxab
 0: xxxab
 1: xxab
 2: xxab
 3: xxab
    *** Failers
No match
    xyab
No match

/(ab|(bc|(de|(?1))))/I
Failed: error 140 at offset 15: recursion could loop indefinitely

/x(ab|(bc|(de|(?1)x)x)x)/I
Failed: error 140 at offset 16: recursion could loop indefinitely

/^([^()]|\((?1)*\))*$/I
Capturing subpattern count = 1
May match empty string
Compile options: <none>
Overall options: anchored
Subject length lower bound = 0
    abc
 0: abc
 1: c
    a(b)c
 0: a(b)c
 1: c
    a(b(c))d
 0: a(b(c))d
 1: d
    *** Failers)
No match
    a(b(c)d
No match

/^>abc>([^()]|\((?1)*\))*<xyz<$/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Last code unit = '<'
Subject length lower bound = 10
   >abc>123<xyz<
 0: >abc>123<xyz<
 1: 3
   >abc>1(2)3<xyz<
 0: >abc>1(2)3<xyz<
 1: 3
   >abc>(1(2)3)<xyz<
 0: >abc>(1(2)3)<xyz<
 1: (1(2)3)

/(a(?1)b)/IB
------------------------------------------------------------------
        Bra
        CBra 1
        a
        Recurse
        b
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/(a(?1)+b)/IB
------------------------------------------------------------------
        Bra
        CBra 1
        a
        Once
        Recurse
        KetRmax
        b
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/^(\d+|\((?1)([+*-])(?1)\)|-(?1))$/I
Capturing subpattern count = 2
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1
    12
 0: 12
 1: 12
    (((2+2)*-3)-7)
 0: (((2+2)*-3)-7)
 1: (((2+2)*-3)-7)
 2: -
    -12
 0: -12
 1: -12
    *** Failers
No match
    ((2+2)*-3)-7)
No match

/^(x(y|(?1){2})z)/I
Capturing subpattern count = 2
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    xyz
 0: xyz
 1: xyz
 2: y
    xxyzxyzz
 0: xxyzxyzz
 1: xxyzxyzz
 2: xyzxyz
    *** Failers
No match
    xxyzz
No match
    xxyzxyzxyzz
No match

/((< (?: (?(R) \d++  | [^<>]*+) | (?2)) * >))/Ix
Capturing subpattern count = 2
Options: extended
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 2
    <>
 0: <>
 1: <>
 2: <>
    <abcd>
 0: <abcd>
 1: <abcd>
 2: <abcd>
    <abc <123> hij>
 0: <abc <123> hij>
 1: <abc <123> hij>
 2: <abc <123> hij>
    <abc <def> hij>
 0: <def>
 1: <def>
 2: <def>
    <abc<>def>
 0: <abc<>def>
 1: <abc<>def>
 2: <abc<>def>
    <abc<>
 0: <>
 1: <>
 2: <>
    *** Failers
No match
    <abc
No match

/(?1)/I
Failed: error 115 at offset 3: reference to non-existent subpattern

/((?2)(abc)/I
Failed: error 114 at offset 10: missing closing parenthesis

/^(abc)def(?1)/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 9
    abcdefabc
 0: abcdefabc
 1: abc

/^(a|b|c)=(?1)+/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3
    a=a
 0: a=a
 1: a
    a=b
 0: a=b
 1: a
    a=bc
 0: a=bc
 1: a

/^(a|b|c)=((?1))+/I
Capturing subpattern count = 2
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3
    a=a
 0: a=a
 1: a
 2: a
    a=b
 0: a=b
 1: a
 2: b
    a=bc
 0: a=bc
 1: a
 2: c

/a(?P<name1>b|c)d(?P<longername2>e)/IB
------------------------------------------------------------------
        Bra
        a
        CBra 1
        b
        Alt
        c
        Ket
        d
        CBra 2
        e
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 2
Named capturing subpatterns:
  longername2   2
  name1         1
First code unit = 'a'
Last code unit = 'e'
Subject length lower bound = 4
    abde
 0: abde
 1: b
 2: e
    acde
 0: acde
 1: c
 2: e

/(?:a(?P<c>c(?P<d>d)))(?P<a>a)/IB
------------------------------------------------------------------
        Bra
        Bra
        a
        CBra 1
        c
        CBra 2
        d
        Ket
        Ket
        Ket
        CBra 3
        a
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 3
Named capturing subpatterns:
  a   3
  c   1
  d   2
First code unit = 'a'
Last code unit = 'a'
Subject length lower bound = 4

/(?P<a>a)...(?P=a)bbb(?P>a)d/IB
------------------------------------------------------------------
        Bra
        CBra 1
        a
        Ket
        Any
        Any
        Any
        \1
        bbb
        Recurse
        d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Max back reference = 1
Named capturing subpatterns:
  a   1
First code unit = 'a'
Last code unit = 'd'
Subject length lower bound = 10

/^\W*(?:(?P<one>(?P<two>.)\W*(?P>one)\W*(?P=two)|)|(?P<three>(?P<four>.)\W*(?P>three)\W*(?P=four)|\W*.\W*))\W*$/Ii
Capturing subpattern count = 4
Max back reference = 4
Named capturing subpatterns:
  four    4
  one     1
  three   3
  two     2
May match empty string
Compile options: caseless
Overall options: anchored caseless
Subject length lower bound = 0
    1221
 0: 1221
 1: 1221
 2: 1
    Satan, oscillate my metallic sonatas!
 0: Satan, oscillate my metallic sonatas!
 1: <unset>
 2: <unset>
 3: Satan, oscillate my metallic sonatas
 4: S
    A man, a plan, a canal: Panama!
 0: A man, a plan, a canal: Panama!
 1: <unset>
 2: <unset>
 3: A man, a plan, a canal: Panama
 4: A
    Able was I ere I saw Elba.
 0: Able was I ere I saw Elba.
 1: <unset>
 2: <unset>
 3: Able was I ere I saw Elba
 4: A
    *** Failers
No match
    The quick brown fox
No match

/((?(R)a|b))\1(?1)?/I
Capturing subpattern count = 1
Max back reference = 1
Subject length lower bound = 2
  bb
 0: bb
 1: b
  bbaa
 0: bba
 1: b

/(.*)a/Is
Capturing subpattern count = 1
Compile options: dotall
Overall options: anchored dotall
Last code unit = 'a'
Subject length lower bound = 1

/(.*)a\1/Is
Capturing subpattern count = 1
Max back reference = 1
Options: dotall
Last code unit = 'a'
Subject length lower bound = 1

/(.*)a(b)\2/Is
Capturing subpattern count = 2
Max back reference = 2
Compile options: dotall
Overall options: anchored dotall
Last code unit = 'b'
Subject length lower bound = 3

/((.*)a|(.*)b)z/Is
Capturing subpattern count = 3
Compile options: dotall
Overall options: anchored dotall
Last code unit = 'z'
Subject length lower bound = 2

/((.*)a|(.*)b)z\1/Is
Capturing subpattern count = 3
Max back reference = 1
Options: dotall
Last code unit = 'z'
Subject length lower bound = 3

/((.*)a|(.*)b)z\2/Is
Capturing subpattern count = 3
Max back reference = 2
Options: dotall
Last code unit = 'z'
Subject length lower bound = 2

/((.*)a|(.*)b)z\3/Is
Capturing subpattern count = 3
Max back reference = 3
Options: dotall
Last code unit = 'z'
Subject length lower bound = 2

/((.*)a|^(.*)b)z\3/Is
Capturing subpattern count = 3
Max back reference = 3
Compile options: dotall
Overall options: anchored dotall
Last code unit = 'z'
Subject length lower bound = 2

/(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)a/Is
Capturing subpattern count = 31
May match empty string
Compile options: dotall
Overall options: anchored dotall
Subject length lower bound = 0

/(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)a\31/Is
Capturing subpattern count = 31
Max back reference = 31
May match empty string
Options: dotall
Subject length lower bound = 0

/(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)a\32/Is
Capturing subpattern count = 32
Max back reference = 32
May match empty string
Options: dotall
Subject length lower bound = 0

/(a)(bc)/IB,no_auto_capture
------------------------------------------------------------------
        Bra
        Bra
        a
        Ket
        Bra
        bc
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: no_auto_capture
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3
  abc
 0: abc

/(?P<one>a)(bc)/IB,no_auto_capture
------------------------------------------------------------------
        Bra
        CBra 1
        a
        Ket
        Bra
        bc
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Named capturing subpatterns:
  one   1
Options: no_auto_capture
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3
  abc
 0: abc
 1: a

/(a)(?P<named>bc)/IB,no_auto_capture
------------------------------------------------------------------
        Bra
        Bra
        a
        Ket
        CBra 1
        bc
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Named capturing subpatterns:
  named   1
Options: no_auto_capture
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3

/(a+)*zz/I
Capturing subpattern count = 1
Starting code units: a z 
Last code unit = 'z'
Subject length lower bound = 2
  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaazzbbbbbb\=find_limits
Minimum match limit = 8
Minimum recursion limit = 6
 0: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaazz
 1: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
  aaaaaaaaaaaaaz\=find_limits
Minimum match limit = 32768
Minimum recursion limit = 29
No match

/(aaa(?C1)bbb|ab)/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
   aaabbb
--->aaabbb
  1 ^  ^       b
 0: aaabbb
 1: aaabbb
   aaabbb\=callout_data=0
--->aaabbb
  1 ^  ^       b
 0: aaabbb
 1: aaabbb
   aaabbb\=callout_data=1
--->aaabbb
  1 ^  ^       b
Callout data = 1
 0: ab
 1: ab
   aaabbb\=callout_data=-1
--->aaabbb
  1 ^  ^       b
Callout data = -1
No match

/ab(?P<one>cd)ef(?P<two>gh)/I
Capturing subpattern count = 2
Named capturing subpatterns:
  one   1
  two   2
First code unit = 'a'
Last code unit = 'h'
Subject length lower bound = 8
    abcdefgh
 0: abcdefgh
 1: cd
 2: gh
    abcdefgh\=copy=1,get=two
 0: abcdefgh
 1: cd
 2: gh
 1C cd (2)
  G gh (2) two
    abcdefgh\=copy=one,copy=two
 0: abcdefgh
 1: cd
 2: gh
  C cd (2) one
  C gh (2) two
    abcdefgh\=copy=three
 0: abcdefgh
 1: cd
 2: gh
copy substring 'three' failed (-47): unknown or unset substring

/(?P<Tes>)(?P<Test>)/IB
------------------------------------------------------------------
        Bra
        CBra 1
        Ket
        CBra 2
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 2
Named capturing subpatterns:
  Tes    1
  Test   2
May match empty string
Subject length lower bound = 0

/(?P<Test>)(?P<Tes>)/IB
------------------------------------------------------------------
        Bra
        CBra 1
        Ket
        CBra 2
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 2
Named capturing subpatterns:
  Tes    2
  Test   1
May match empty string
Subject length lower bound = 0

/(?P<Z>zz)(?P<A>aa)/I
Capturing subpattern count = 2
Named capturing subpatterns:
  A   2
  Z   1
First code unit = 'z'
Last code unit = 'a'
Subject length lower bound = 4
    zzaa\=copy=Z
 0: zzaa
 1: zz
 2: aa
  C zz (2) Z
    zzaa\=copy=A
 0: zzaa
 1: zz
 2: aa
  C aa (2) A

/(?P<x>eks)(?P<x>eccs)/I
Failed: error 143 at offset 15: two named subpatterns have the same name (PCRE2_DUPNAMES not set)

/(?P<abc>abc(?P<def>def)(?P<abc>xyz))/I
Failed: error 143 at offset 30: two named subpatterns have the same name (PCRE2_DUPNAMES not set)

"\[((?P<elem>\d+)(,(?P>elem))*)\]"I
Capturing subpattern count = 3
Named capturing subpatterns:
  elem   2
First code unit = '['
Last code unit = ']'
Subject length lower bound = 3
    [10,20,30,5,5,4,4,2,43,23,4234]
 0: [10,20,30,5,5,4,4,2,43,23,4234]
 1: 10,20,30,5,5,4,4,2,43,23,4234
 2: 10
 3: ,4234
    *** Failers
No match
    []
No match

"\[((?P<elem>\d+)(,(?P>elem))*)?\]"I
Capturing subpattern count = 3
Named capturing subpatterns:
  elem   2
First code unit = '['
Last code unit = ']'
Subject length lower bound = 2
    [10,20,30,5,5,4,4,2,43,23,4234]
 0: [10,20,30,5,5,4,4,2,43,23,4234]
 1: 10,20,30,5,5,4,4,2,43,23,4234
 2: 10
 3: ,4234
    []
 0: []

/(a(b(?2)c))?/IB
------------------------------------------------------------------
        Bra
        Brazero
        CBra 1
        a
        CBra 2
        b
        Recurse
        c
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 2
May match empty string
Subject length lower bound = 0

/(a(b(?2)c))*/IB
------------------------------------------------------------------
        Bra
        Brazero
        CBra 1
        a
        CBra 2
        b
        Recurse
        c
        Ket
        KetRmax
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 2
May match empty string
Subject length lower bound = 0

/(a(b(?2)c)){0,2}/IB
------------------------------------------------------------------
        Bra
        Brazero
        Bra
        CBra 1
        a
        CBra 2
        b
        Recurse
        c
        Ket
        Ket
        Brazero
        CBra 1
        a
        CBra 2
        b
        Recurse
        c
        Ket
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 2
May match empty string
Subject length lower bound = 0

/[ab]{1}+/IB
------------------------------------------------------------------
        Bra
        [ab]{1,1}+
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: a b 
Subject length lower bound = 1

/((w\/|-|with)*(free|immediate)*.*?shipping\s*[!.-]*)/Ii
Capturing subpattern count = 3
Options: caseless
Last code unit = 'g' (caseless)
Subject length lower bound = 8
     Baby Bjorn Active Carrier - With free SHIPPING!!
 0: Baby Bjorn Active Carrier - With free SHIPPING!!
 1: Baby Bjorn Active Carrier - With free SHIPPING!!

/((w\/|-|with)*(free|immediate)*.*?shipping\s*[!.-]*)/Ii
Capturing subpattern count = 3
Options: caseless
Last code unit = 'g' (caseless)
Subject length lower bound = 8
     Baby Bjorn Active Carrier - With free SHIPPING!!
 0: Baby Bjorn Active Carrier - With free SHIPPING!!
 1: Baby Bjorn Active Carrier - With free SHIPPING!!

/a*.*b/IB
------------------------------------------------------------------
        Bra
        a*
        Any*
        b
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Last code unit = 'b'
Subject length lower bound = 1

/(a|b)*.?c/IB
------------------------------------------------------------------
        Bra
        Brazero
        CBra 1
        a
        Alt
        b
        KetRmax
        Any?
        c
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Last code unit = 'c'
Subject length lower bound = 1

/abc(?C255)de(?C)f/IB
------------------------------------------------------------------
        Bra
        abc
        Callout 255 10 1
        de
        Callout 0 16 1
        f
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'f'
Subject length lower bound = 6

/abcde/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 1
        a
        Callout 255 1 1
        b
        Callout 255 2 1
        c
        Callout 255 3 1
        d
        Callout 255 4 1
        e
        Callout 255 5 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: auto_callout
First code unit = 'a'
Last code unit = 'e'
Subject length lower bound = 5
  abcde
--->abcde
 +0 ^         a
 +1 ^^        b
 +2 ^ ^       c
 +3 ^  ^      d
 +4 ^   ^     e
 +5 ^    ^    
 0: abcde
  abcdfe
--->abcdfe
 +0 ^          a
 +1 ^^         b
 +2 ^ ^        c
 +3 ^  ^       d
 +4 ^   ^      e
No match

/a*b/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 2
        a*+
        Callout 255 2 1
        b
        Callout 255 3 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: auto_callout
Starting code units: a b 
Last code unit = 'b'
Subject length lower bound = 1
  ab
--->ab
 +0 ^      a*
 +2 ^^     b
 +3 ^ ^    
 0: ab
  aaaab
--->aaaab
 +0 ^         a*
 +2 ^   ^     b
 +3 ^    ^    
 0: aaaab
  aaaacb
--->aaaacb
 +0 ^          a*
 +2 ^   ^      b
 +0  ^         a*
 +2  ^  ^      b
 +0   ^        a*
 +2   ^ ^      b
 +0    ^       a*
 +2    ^^      b
 +0      ^     a*
 +2      ^     b
 +3      ^^    
 0: b

/a*b/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 2
        a*+
        Callout 255 2 1
        b
        Callout 255 3 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: auto_callout
Starting code units: a b 
Last code unit = 'b'
Subject length lower bound = 1
  ab
--->ab
 +0 ^      a*
 +2 ^^     b
 +3 ^ ^    
 0: ab
  aaaab
--->aaaab
 +0 ^         a*
 +2 ^   ^     b
 +3 ^    ^    
 0: aaaab
  aaaacb
--->aaaacb
 +0 ^          a*
 +2 ^   ^      b
 +0  ^         a*
 +2  ^  ^      b
 +0   ^        a*
 +2   ^ ^      b
 +0    ^       a*
 +2    ^^      b
 +0      ^     a*
 +2      ^     b
 +3      ^^    
 0: b

/a+b/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 2
        a++
        Callout 255 2 1
        b
        Callout 255 3 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: auto_callout
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
  ab
--->ab
 +0 ^      a+
 +2 ^^     b
 +3 ^ ^    
 0: ab
  aaaab
--->aaaab
 +0 ^         a+
 +2 ^   ^     b
 +3 ^    ^    
 0: aaaab
  aaaacb
--->aaaacb
 +0 ^          a+
 +2 ^   ^      b
 +0  ^         a+
 +2  ^  ^      b
 +0   ^        a+
 +2   ^ ^      b
 +0    ^       a+
 +2    ^^      b
No match

/(abc|def)x/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 9
        CBra 1
        Callout 255 1 1
        a
        Callout 255 2 1
        b
        Callout 255 3 1
        c
        Callout 255 4 0
        Alt
        Callout 255 5 1
        d
        Callout 255 6 1
        e
        Callout 255 7 1
        f
        Callout 255 8 0
        Ket
        Callout 255 9 1
        x
        Callout 255 10 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Options: auto_callout
Starting code units: a d 
Last code unit = 'x'
Subject length lower bound = 4
  abcx
--->abcx
 +0 ^        (abc|def)
 +1 ^        a
 +2 ^^       b
 +3 ^ ^      c
 +4 ^  ^     |
 +9 ^  ^     x
+10 ^   ^    
 0: abcx
 1: abc
  defx
--->defx
 +0 ^        (abc|def)
 +1 ^        a
 +5 ^        d
 +6 ^^       e
 +7 ^ ^      f
 +8 ^  ^     )
 +9 ^  ^     x
+10 ^   ^    
 0: defx
 1: def
  ** Failers 
No match
  abcdefzx
--->abcdefzx
 +0 ^            (abc|def)
 +1 ^            a
 +2 ^^           b
 +3 ^ ^          c
 +4 ^  ^         |
 +9 ^  ^         x
 +5 ^            d
 +0    ^         (abc|def)
 +1    ^         a
 +5    ^         d
 +6    ^^        e
 +7    ^ ^       f
 +8    ^  ^      )
 +9    ^  ^      x
No match

/(abc|def)x/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 9
        CBra 1
        Callout 255 1 1
        a
        Callout 255 2 1
        b
        Callout 255 3 1
        c
        Callout 255 4 0
        Alt
        Callout 255 5 1
        d
        Callout 255 6 1
        e
        Callout 255 7 1
        f
        Callout 255 8 0
        Ket
        Callout 255 9 1
        x
        Callout 255 10 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Options: auto_callout
Starting code units: a d 
Last code unit = 'x'
Subject length lower bound = 4
  abcx
--->abcx
 +0 ^        (abc|def)
 +1 ^        a
 +2 ^^       b
 +3 ^ ^      c
 +4 ^  ^     |
 +9 ^  ^     x
+10 ^   ^    
 0: abcx
 1: abc
  defx
--->defx
 +0 ^        (abc|def)
 +1 ^        a
 +5 ^        d
 +6 ^^       e
 +7 ^ ^      f
 +8 ^  ^     )
 +9 ^  ^     x
+10 ^   ^    
 0: defx
 1: def
  ** Failers 
No match
  abcdefzx
--->abcdefzx
 +0 ^            (abc|def)
 +1 ^            a
 +2 ^^           b
 +3 ^ ^          c
 +4 ^  ^         |
 +9 ^  ^         x
 +5 ^            d
 +0    ^         (abc|def)
 +1    ^         a
 +5    ^         d
 +6    ^^        e
 +7    ^ ^       f
 +8    ^  ^      )
 +9    ^  ^      x
No match

/(ab|cd){3,4}/I,auto_callout
Capturing subpattern count = 1
Options: auto_callout
Starting code units: a c 
Subject length lower bound = 6
  ababab
--->ababab
 +0 ^          (ab|cd){3,4}
 +1 ^          a
 +2 ^^         b
 +3 ^ ^        |
 +1 ^ ^        a
 +2 ^  ^       b
 +3 ^   ^      |
 +1 ^   ^      a
 +2 ^    ^     b
 +3 ^     ^    |
 +1 ^     ^    a
 +4 ^     ^    c
+12 ^     ^    
 0: ababab
 1: ab
  abcdabcd
--->abcdabcd
 +0 ^            (ab|cd){3,4}
 +1 ^            a
 +2 ^^           b
 +3 ^ ^          |
 +1 ^ ^          a
 +4 ^ ^          c
 +5 ^  ^         d
 +6 ^   ^        )
 +1 ^   ^        a
 +2 ^    ^       b
 +3 ^     ^      |
 +1 ^     ^      a
 +4 ^     ^      c
 +5 ^      ^     d
 +6 ^       ^    )
+12 ^       ^    
 0: abcdabcd
 1: cd
  abcdcdcdcdcd
--->abcdcdcdcdcd
 +0 ^                (ab|cd){3,4}
 +1 ^                a
 +2 ^^               b
 +3 ^ ^              |
 +1 ^ ^              a
 +4 ^ ^              c
 +5 ^  ^             d
 +6 ^   ^            )
 +1 ^   ^            a
 +4 ^   ^            c
 +5 ^    ^           d
 +6 ^     ^          )
 +1 ^     ^          a
 +4 ^     ^          c
 +5 ^      ^         d
 +6 ^       ^        )
+12 ^       ^        
 0: abcdcdcd
 1: cd

/([ab]{,4}c|xy)/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 14
        CBra 1
        Callout 255 1 4
        [ab]
        Callout 255 5 1
        {
        Callout 255 6 1
        ,
        Callout 255 7 1
        4
        Callout 255 8 1
        }
        Callout 255 9 1
        c
        Callout 255 10 0
        Alt
        Callout 255 11 1
        x
        Callout 255 12 1
        y
        Callout 255 13 0
        Ket
        Callout 255 14 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Options: auto_callout
Starting code units: a b x 
Subject length lower bound = 2
    Note: that { does NOT introduce a quantifier
--->Note: that { does NOT introduce a quantifier
 +0         ^                                        ([ab]{,4}c|xy)
 +1         ^                                        [ab]
 +5         ^^                                       {
+11         ^                                        x
 +0                                 ^                ([ab]{,4}c|xy)
 +1                                 ^                [ab]
 +5                                 ^^               {
+11                                 ^                x
 +0                                     ^            ([ab]{,4}c|xy)
 +1                                     ^            [ab]
 +5                                     ^^           {
+11                                     ^            x
No match

/([ab]{,4}c|xy)/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 14
        CBra 1
        Callout 255 1 4
        [ab]
        Callout 255 5 1
        {
        Callout 255 6 1
        ,
        Callout 255 7 1
        4
        Callout 255 8 1
        }
        Callout 255 9 1
        c
        Callout 255 10 0
        Alt
        Callout 255 11 1
        x
        Callout 255 12 1
        y
        Callout 255 13 0
        Ket
        Callout 255 14 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Options: auto_callout
Starting code units: a b x 
Subject length lower bound = 2
    Note: that { does NOT introduce a quantifier
--->Note: that { does NOT introduce a quantifier
 +0         ^                                        ([ab]{,4}c|xy)
 +1         ^                                        [ab]
 +5         ^^                                       {
+11         ^                                        x
 +0                                 ^                ([ab]{,4}c|xy)
 +1                                 ^                [ab]
 +5                                 ^^               {
+11                                 ^                x
 +0                                     ^            ([ab]{,4}c|xy)
 +1                                     ^            [ab]
 +5                                     ^^           {
+11                                     ^            x
No match

/([ab]{1,4}c|xy){4,5}?123/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 21
        CBra 1
        Callout 255 1 9
        [ab]{1,4}+
        Callout 255 10 1
        c
        Callout 255 11 0
        Alt
        Callout 255 12 1
        x
        Callout 255 13 1
        y
        Callout 255 14 0
        Ket
        CBra 1
        Callout 255 1 9
        [ab]{1,4}+
        Callout 255 10 1
        c
        Callout 255 11 0
        Alt
        Callout 255 12 1
        x
        Callout 255 13 1
        y
        Callout 255 14 0
        Ket
        CBra 1
        Callout 255 1 9
        [ab]{1,4}+
        Callout 255 10 1
        c
        Callout 255 11 0
        Alt
        Callout 255 12 1
        x
        Callout 255 13 1
        y
        Callout 255 14 0
        Ket
        CBra 1
        Callout 255 1 9
        [ab]{1,4}+
        Callout 255 10 1
        c
        Callout 255 11 0
        Alt
        Callout 255 12 1
        x
        Callout 255 13 1
        y
        Callout 255 14 0
        Ket
        Braminzero
        CBra 1
        Callout 255 1 9
        [ab]{1,4}+
        Callout 255 10 1
        c
        Callout 255 11 0
        Alt
        Callout 255 12 1
        x
        Callout 255 13 1
        y
        Callout 255 14 0
        Ket
        Callout 255 21 1
        1
        Callout 255 22 1
        2
        Callout 255 23 1
        3
        Callout 255 24 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Options: auto_callout
Starting code units: a b x 
Last code unit = '3'
Subject length lower bound = 11
    aacaacaacaacaac123
--->aacaacaacaacaac123
 +0 ^                      ([ab]{1,4}c|xy){4,5}?
 +1 ^                      [ab]{1,4}
+10 ^ ^                    c
+11 ^  ^                   |
 +1 ^  ^                   [ab]{1,4}
+10 ^    ^                 c
+11 ^     ^                |
 +1 ^     ^                [ab]{1,4}
+10 ^       ^              c
+11 ^        ^             |
 +1 ^        ^             [ab]{1,4}
+10 ^          ^           c
+11 ^           ^          |
+21 ^           ^          1
 +1 ^           ^          [ab]{1,4}
+10 ^             ^        c
+11 ^              ^       |
+21 ^              ^       1
+22 ^               ^      2
+23 ^                ^     3
+24 ^                 ^    
 0: aacaacaacaacaac123
 1: aac

/\b.*/I
Capturing subpattern count = 0
Max lookbehind = 1
May match empty string
Subject length lower bound = 0
  ab cd\=offset=1
 0:  cd

/\b.*/Is
Capturing subpattern count = 0
Max lookbehind = 1
May match empty string
Options: dotall
Subject length lower bound = 0
  ab cd\=offset=1
 0:  cd

/(?!.bcd).*/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
  Xbcd12345
 0: bcd12345

/abcde/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'e'
Subject length lower bound = 5
    ab\=ps
Partial match: ab
    abc\=ps
Partial match: abc
    abcd\=ps
Partial match: abcd
    abcde\=ps
 0: abcde
    the quick brown abc\=ps
Partial match: abc
    ** Failers\=ps
No match
    the quick brown abxyz fox\=ps
No match

"^(0?[1-9]|[12][0-9]|3[01])/(0?[1-9]|1[012])/(20)?\d\d$"I
Capturing subpattern count = 3
Compile options: <none>
Overall options: anchored
Last code unit = '/'
Subject length lower bound = 6
    13/05/04\=ps
 0: 13/05/04
 1: 13
 2: 05
    13/5/2004\=ps
 0: 13/5/2004
 1: 13
 2: 5
 3: 20
    02/05/09\=ps
 0: 02/05/09
 1: 02
 2: 05
    1\=ps
Partial match: 1
    1/2\=ps
Partial match: 1/2
    1/2/0\=ps
Partial match: 1/2/0
    1/2/04\=ps
 0: 1/2/04
 1: 1
 2: 2
    0\=ps
Partial match: 0
    02/\=ps
Partial match: 02/
    02/0\=ps
Partial match: 02/0
    02/1\=ps
Partial match: 02/1
    ** Failers\=ps
No match
    \=ps
No match
    123\=ps
No match
    33/4/04\=ps
No match
    3/13/04\=ps
No match
    0/1/2003\=ps
No match
    0/\=ps
No match
    02/0/\=ps
No match
    02/13\=ps
No match

/0{0,2}ABC/I
Capturing subpattern count = 0
Starting code units: 0 A 
Last code unit = 'C'
Subject length lower bound = 3

/\d{3,}ABC/I
Capturing subpattern count = 0
Starting code units: 0 1 2 3 4 5 6 7 8 9 
Last code unit = 'C'
Subject length lower bound = 6

/\d*ABC/I
Capturing subpattern count = 0
Starting code units: 0 1 2 3 4 5 6 7 8 9 A 
Last code unit = 'C'
Subject length lower bound = 3

/[abc]+DE/I
Capturing subpattern count = 0
Starting code units: a b c 
Last code unit = 'E'
Subject length lower bound = 3

/[abc]?123/I
Capturing subpattern count = 0
Starting code units: 1 a b c 
Last code unit = '3'
Subject length lower bound = 3
    123\=ps
 0: 123
    a\=ps
Partial match: a
    b\=ps
Partial match: b
    c\=ps
Partial match: c
    c12\=ps
Partial match: c12
    c123\=ps
 0: c123

/^(?:\d){3,5}X/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Last code unit = 'X'
Subject length lower bound = 4
    1\=ps
Partial match: 1
    123\=ps
Partial match: 123
    123X
 0: 123X
    1234\=ps
Partial match: 1234
    1234X
 0: 1234X
    12345\=ps
Partial match: 12345
    12345X
 0: 12345X
    *** Failers
No match
    1X
No match
    123456\=ps
No match

"<(\w+)/?>(.)*</(\1)>"Igms
Capturing subpattern count = 3
Max back reference = 1
Options: multiline dotall
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 7
    <!DOCTYPE seite SYSTEM "http://www.lco.lineas.de/xmlCms.dtd">\n<seite>\n<dokumenteninformation>\n<seitentitel>Partner der LCO</seitentitel>\n<sprache>de</sprache>\n<seitenbeschreibung>Partner der LINEAS Consulting\nGmbH</seitenbeschreibung>\n<schluesselworte>LINEAS Consulting GmbH Hamburg\nPartnerfirmen</schluesselworte>\n<revisit>30 days</revisit>\n<robots>index,follow</robots>\n<menueinformation>\n<aktiv>ja</aktiv>\n<menueposition>3</menueposition>\n<menuetext>Partner</menuetext>\n</menueinformation>\n<lastedited>\n<autor>LCO</autor>\n<firma>LINEAS Consulting</firma>\n<datum>15.10.2003</datum>\n</lastedited>\n</dokumenteninformation>\n<inhalt>\n\n<absatzueberschrift>Die Partnerfirmen der LINEAS Consulting\nGmbH</absatzueberschrift>\n\n<absatz><link ziel="http://www.ca.com/" zielfenster="_blank">\n<bild name="logo_ca.gif" rahmen="no"/></link> <link\nziel="http://www.ey.com/" zielfenster="_blank"><bild\nname="logo_euy.gif" rahmen="no"/></link>\n</absatz>\n\n<absatz><link ziel="http://www.cisco.de/" zielfenster="_blank">\n<bild name="logo_cisco.gif" rahmen="ja"/></link></absatz>\n\n<absatz><link ziel="http://www.atelion.de/"\nzielfenster="_blank"><bild\nname="logo_atelion.gif" rahmen="no"/></link>\n</absatz>\n\n<absatz><link ziel="http://www.line-information.de/"\nzielfenster="_blank">\n<bild name="logo_line_information.gif" rahmen="no"/></link>\n</absatz>\n\n<absatz><bild name="logo_aw.gif" rahmen="no"/></absatz>\n\n<absatz><link ziel="http://www.incognis.de/"\nzielfenster="_blank"><bild\nname="logo_incognis.gif" rahmen="no"/></link></absatz>\n\n<absatz><link ziel="http://www.addcraft.com/"\nzielfenster="_blank"><bild\nname="logo_addcraft.gif" rahmen="no"/></link></absatz>\n\n<absatz><link ziel="http://www.comendo.com/"\nzielfenster="_blank"><bild\nname="logo_comendo.gif" rahmen="no"/></link></absatz>\n\n</inhalt>\n</seite>\=jitstack=1024
 0: <seite>\x0a<dokumenteninformation>\x0a<seitentitel>Partner der LCO</seitentitel>\x0a<sprache>de</sprache>\x0a<seitenbeschreibung>Partner der LINEAS Consulting\x0aGmbH</seitenbeschreibung>\x0a<schluesselworte>LINEAS Consulting GmbH Hamburg\x0aPartnerfirmen</schluesselworte>\x0a<revisit>30 days</revisit>\x0a<robots>index,follow</robots>\x0a<menueinformation>\x0a<aktiv>ja</aktiv>\x0a<menueposition>3</menueposition>\x0a<menuetext>Partner</menuetext>\x0a</menueinformation>\x0a<lastedited>\x0a<autor>LCO</autor>\x0a<firma>LINEAS Consulting</firma>\x0a<datum>15.10.2003</datum>\x0a</lastedited>\x0a</dokumenteninformation>\x0a<inhalt>\x0a\x0a<absatzueberschrift>Die Partnerfirmen der LINEAS Consulting\x0aGmbH</absatzueberschrift>\x0a\x0a<absatz><link ziel="http://www.ca.com/" zielfenster="_blank">\x0a<bild name="logo_ca.gif" rahmen="no"/></link> <link\x0aziel="http://www.ey.com/" zielfenster="_blank"><bild\x0aname="logo_euy.gif" rahmen="no"/></link>\x0a</absatz>\x0a\x0a<absatz><link ziel="http://www.cisco.de/" zielfenster="_blank">\x0a<bild name="logo_cisco.gif" rahmen="ja"/></link></absatz>\x0a\x0a<absatz><link ziel="http://www.atelion.de/"\x0azielfenster="_blank"><bild\x0aname="logo_atelion.gif" rahmen="no"/></link>\x0a</absatz>\x0a\x0a<absatz><link ziel="http://www.line-information.de/"\x0azielfenster="_blank">\x0a<bild name="logo_line_information.gif" rahmen="no"/></link>\x0a</absatz>\x0a\x0a<absatz><bild name="logo_aw.gif" rahmen="no"/></absatz>\x0a\x0a<absatz><link ziel="http://www.incognis.de/"\x0azielfenster="_blank"><bild\x0aname="logo_incognis.gif" rahmen="no"/></link></absatz>\x0a\x0a<absatz><link ziel="http://www.addcraft.com/"\x0azielfenster="_blank"><bild\x0aname="logo_addcraft.gif" rahmen="no"/></link></absatz>\x0a\x0a<absatz><link ziel="http://www.comendo.com/"\x0azielfenster="_blank"><bild\x0aname="logo_comendo.gif" rahmen="no"/></link></absatz>\x0a\x0a</inhalt>\x0a</seite>
 1: seite
 2: \x0a
 3: seite

/line\nbreak/I
Capturing subpattern count = 0
Contains explicit CR or LF match
First code unit = 'l'
Last code unit = 'k'
Subject length lower bound = 10
    this is a line\nbreak
 0: line\x0abreak
    line one\nthis is a line\nbreak in the second line
 0: line\x0abreak

/line\nbreak/I,firstline
Capturing subpattern count = 0
Contains explicit CR or LF match
Options: firstline
First code unit = 'l'
Last code unit = 'k'
Subject length lower bound = 10
    this is a line\nbreak
 0: line\x0abreak
    ** Failers
No match
    line one\nthis is a line\nbreak in the second line
No match

/line\nbreak/Im,firstline
Capturing subpattern count = 0
Contains explicit CR or LF match
Options: multiline firstline
First code unit = 'l'
Last code unit = 'k'
Subject length lower bound = 10
    this is a line\nbreak
 0: line\x0abreak
    ** Failers
No match
    line one\nthis is a line\nbreak in the second line
No match

/(?i)(?-i)AbCd/I
Capturing subpattern count = 0
First code unit = 'A'
Last code unit = 'd'
Subject length lower bound = 4
    AbCd
 0: AbCd
    ** Failers
No match
    abcd
No match

/a{11111111111111111111}/I
Failed: error 105 at offset 8: number too big in {} quantifier

/(){64294967295}/I
Failed: error 105 at offset 9: number too big in {} quantifier

/(){2,4294967295}/I
Failed: error 105 at offset 11: number too big in {} quantifier

"(?i:a)(?i:b)(?i:c)(?i:d)(?i:e)(?i:f)(?i:g)(?i:h)(?i:i)(?i:j)(k)(?i:l)A\1B"I
Capturing subpattern count = 1
Max back reference = 1
First code unit = 'a' (caseless)
Last code unit = 'B'
Subject length lower bound = 15
    abcdefghijklAkB
 0: abcdefghijklAkB
 1: k

"(?P<n0>a)(?P<n1>b)(?P<n2>c)(?P<n3>d)(?P<n4>e)(?P<n5>f)(?P<n6>g)(?P<n7>h)(?P<n8>i)(?P<n9>j)(?P<n10>k)(?P<n11>l)A\11B"I
Capturing subpattern count = 12
Max back reference = 11
Named capturing subpatterns:
  n0    1
  n1    2
  n10  11
  n11  12
  n2    3
  n3    4
  n4    5
  n5    6
  n6    7
  n7    8
  n8    9
  n9   10
First code unit = 'a'
Last code unit = 'B'
Subject length lower bound = 15
    abcdefghijklAkB
 0: abcdefghijklAkB
 1: a
 2: b
 3: c
 4: d
 5: e
 6: f
 7: g
 8: h
 9: i
10: j
11: k
12: l

"(a)(b)(c)(d)(e)(f)(g)(h)(i)(j)(k)(l)A\11B"I
Capturing subpattern count = 12
Max back reference = 11
First code unit = 'a'
Last code unit = 'B'
Subject length lower bound = 15
    abcdefghijklAkB
 0: abcdefghijklAkB
 1: a
 2: b
 3: c
 4: d
 5: e
 6: f
 7: g
 8: h
 9: i
10: j
11: k
12: l

"(?P<name0>a)(?P<name1>a)(?P<name2>a)(?P<name3>a)(?P<name4>a)(?P<name5>a)(?P<name6>a)(?P<name7>a)(?P<name8>a)(?P<name9>a)(?P<name10>a)(?P<name11>a)(?P<name12>a)(?P<name13>a)(?P<name14>a)(?P<name15>a)(?P<name16>a)(?P<name17>a)(?P<name18>a)(?P<name19>a)(?P<name20>a)(?P<name21>a)(?P<name22>a)(?P<name23>a)(?P<name24>a)(?P<name25>a)(?P<name26>a)(?P<name27>a)(?P<name28>a)(?P<name29>a)(?P<name30>a)(?P<name31>a)(?P<name32>a)(?P<name33>a)(?P<name34>a)(?P<name35>a)(?P<name36>a)(?P<name37>a)(?P<name38>a)(?P<name39>a)(?P<name40>a)(?P<name41>a)(?P<name42>a)(?P<name43>a)(?P<name44>a)(?P<name45>a)(?P<name46>a)(?P<name47>a)(?P<name48>a)(?P<name49>a)(?P<name50>a)(?P<name51>a)(?P<name52>a)(?P<name53>a)(?P<name54>a)(?P<name55>a)(?P<name56>a)(?P<name57>a)(?P<name58>a)(?P<name59>a)(?P<name60>a)(?P<name61>a)(?P<name62>a)(?P<name63>a)(?P<name64>a)(?P<name65>a)(?P<name66>a)(?P<name67>a)(?P<name68>a)(?P<name69>a)(?P<name70>a)(?P<name71>a)(?P<name72>a)(?P<name73>a)(?P<name74>a)(?P<name75>a)(?P<name76>a)(?P<name77>a)(?P<name78>a)(?P<name79>a)(?P<name80>a)(?P<name81>a)(?P<name82>a)(?P<name83>a)(?P<name84>a)(?P<name85>a)(?P<name86>a)(?P<name87>a)(?P<name88>a)(?P<name89>a)(?P<name90>a)(?P<name91>a)(?P<name92>a)(?P<name93>a)(?P<name94>a)(?P<name95>a)(?P<name96>a)(?P<name97>a)(?P<name98>a)(?P<name99>a)(?P<name100>a)"I
Capturing subpattern count = 101
Named capturing subpatterns:
  name0     1
  name1     2
  name10   11
  name100 101
  name11   12
  name12   13
  name13   14
  name14   15
  name15   16
  name16   17
  name17   18
  name18   19
  name19   20
  name2     3
  name20   21
  name21   22
  name22   23
  name23   24
  name24   25
  name25   26
  name26   27
  name27   28
  name28   29
  name29   30
  name3     4
  name30   31
  name31   32
  name32   33
  name33   34
  name34   35
  name35   36
  name36   37
  name37   38
  name38   39
  name39   40
  name4     5
  name40   41
  name41   42
  name42   43
  name43   44
  name44   45
  name45   46
  name46   47
  name47   48
  name48   49
  name49   50
  name5     6
  name50   51
  name51   52
  name52   53
  name53   54
  name54   55
  name55   56
  name56   57
  name57   58
  name58   59
  name59   60
  name6     7
  name60   61
  name61   62
  name62   63
  name63   64
  name64   65
  name65   66
  name66   67
  name67   68
  name68   69
  name69   70
  name7     8
  name70   71
  name71   72
  name72   73
  name73   74
  name74   75
  name75   76
  name76   77
  name77   78
  name78   79
  name79   80
  name8     9
  name80   81
  name81   82
  name82   83
  name83   84
  name84   85
  name85   86
  name86   87
  name87   88
  name88   89
  name89   90
  name9    10
  name90   91
  name91   92
  name92   93
  name93   94
  name94   95
  name95   96
  name96   97
  name97   98
  name98   99
  name99  100
First code unit = 'a'
Last code unit = 'a'
Subject length lower bound = 101
    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
Matched, but too many substrings
 0: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
 1: a
 2: a
 3: a
 4: a
 5: a
 6: a
 7: a
 8: a
 9: a
10: a
11: a
12: a
13: a
14: a

"(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)"I
Capturing subpattern count = 101
First code unit = 'a'
Last code unit = 'a'
Subject length lower bound = 101
    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
Matched, but too many substrings
 0: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
 1: a
 2: a
 3: a
 4: a
 5: a
 6: a
 7: a
 8: a
 9: a
10: a
11: a
12: a
13: a
14: a

/[^()]*(?:\((?R)\)[^()]*)*/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    (this(and)that
 0: 
    (this(and)that)
 0: (this(and)that)
    (this(and)that)stuff
 0: (this(and)that)stuff

/[^()]*(?:\((?>(?R))\)[^()]*)*/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    (this(and)that
 0: 
    (this(and)that)
 0: (this(and)that)

/[^()]*(?:\((?R)\))*[^()]*/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    (this(and)that
 0: 
    (this(and)that)
 0: (this(and)that)

/(?:\((?R)\))*[^()]*/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    (this(and)that
 0: 
    (this(and)that)
 0: 
    ((this))
 0: ((this))

/(?:\((?R)\))|[^()]*/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    (this(and)that
 0: 
    (this(and)that)
 0: 
    (this)
 0: (this)
    ((this))
 0: ((this))

/\x{0000ff}/I
Capturing subpattern count = 0
First code unit = \xff
Subject length lower bound = 1

/^((?P<A>a1)|(?P<A>a2)b)/I
Failed: error 143 at offset 17: two named subpatterns have the same name (PCRE2_DUPNAMES not set)

/^((?P<A>a1)|(?P<A>a2)b)/I,dupnames
Capturing subpattern count = 3
Named capturing subpatterns:
  A   2
  A   3
Compile options: dupnames
Overall options: anchored dupnames
Subject length lower bound = 2
    a1b\=copy=A
 0: a1
 1: a1
 2: a1
  C a1 (2) A
    a2b\=copy=A
 0: a2b
 1: a2b
 2: <unset>
 3: a2
  C a2 (2) A
    ** Failers
No match
    a1b\=copy=Z,copy=A
 0: a1
 1: a1
 2: a1
copy substring 'Z' failed (-47): unknown or unset substring
  C a1 (2) A
    
/(?|(?<a>)(?<b>)(?<a>)|(?<a>)(?<b>)(?<a>))/I,dupnames
Capturing subpattern count = 3
Named capturing subpatterns:
  a   1
  a   3
  b   2
May match empty string
Options: dupnames
Subject length lower bound = 0

/^(?P<A>a)(?P<A>b)/I,dupnames
Capturing subpattern count = 2
Named capturing subpatterns:
  A   1
  A   2
Compile options: dupnames
Overall options: anchored dupnames
Subject length lower bound = 2
    ab\=copy=A
 0: ab
 1: a
 2: b
  C a (1) A

/^(?P<A>a)(?P<A>b)|cd/I,dupnames
Capturing subpattern count = 2
Named capturing subpatterns:
  A   1
  A   2
Options: dupnames
Subject length lower bound = 2
    ab\=copy=A
 0: ab
 1: a
 2: b
  C a (1) A
    cd\=copy=A
 0: cd
copy substring 'A' failed (-47): unknown or unset substring

/^(?P<A>a)(?P<A>b)|cd(?P<A>ef)(?P<A>gh)/I,dupnames
Capturing subpattern count = 4
Named capturing subpatterns:
  A   1
  A   2
  A   3
  A   4
Options: dupnames
Subject length lower bound = 2
    cdefgh\=copy=A
 0: cdefgh
 1: <unset>
 2: <unset>
 3: ef
 4: gh
  C ef (2) A

/^((?P<A>a1)|(?P<A>a2)b)/I,dupnames
Capturing subpattern count = 3
Named capturing subpatterns:
  A   2
  A   3
Compile options: dupnames
Overall options: anchored dupnames
Subject length lower bound = 2
    a1b\=get=A
 0: a1
 1: a1
 2: a1
  G a1 (2) A
    a2b\=get=A
 0: a2b
 1: a2b
 2: <unset>
 3: a2
  G a2 (2) A
    ** Failers
No match
    a1b\=get=Z,get=A
 0: a1
 1: a1
 2: a1
get substring 'Z' failed (-47): unknown or unset substring
  G a1 (2) A

/^(?P<A>a)(?P<A>b)/I,dupnames
Capturing subpattern count = 2
Named capturing subpatterns:
  A   1
  A   2
Compile options: dupnames
Overall options: anchored dupnames
Subject length lower bound = 2
    ab\=get=A
 0: ab
 1: a
 2: b
  G a (1) A

/^(?P<A>a)(?P<A>b)|cd/I,dupnames
Capturing subpattern count = 2
Named capturing subpatterns:
  A   1
  A   2
Options: dupnames
Subject length lower bound = 2
    ab\=get=A
 0: ab
 1: a
 2: b
  G a (1) A
    cd\=get=A
 0: cd
get substring 'A' failed (-47): unknown or unset substring

/^(?P<A>a)(?P<A>b)|cd(?P<A>ef)(?P<A>gh)/I,dupnames
Capturing subpattern count = 4
Named capturing subpatterns:
  A   1
  A   2
  A   3
  A   4
Options: dupnames
Subject length lower bound = 2
    cdefgh\=get=A
 0: cdefgh
 1: <unset>
 2: <unset>
 3: ef
 4: gh
  G ef (2) A

/(?J)^((?P<A>a1)|(?P<A>a2)b)/I
Capturing subpattern count = 3
Named capturing subpatterns:
  A   2
  A   3
Compile options: <none>
Overall options: anchored dupnames
Duplicate name status changes
Subject length lower bound = 2
    a1b\=copy=A
 0: a1
 1: a1
 2: a1
  C a1 (2) A
    a2b\=copy=A
 0: a2b
 1: a2b
 2: <unset>
 3: a2
  C a2 (2) A

/^(?P<A>a) (?J:(?P<B>b)(?P<B>c)) (?P<A>d)/I
Failed: error 143 at offset 37: two named subpatterns have the same name (PCRE2_DUPNAMES not set)

/ In this next test, J is not set at the outer level; consequently it isn't
set in the pattern's options; consequently pcre_get_named_substring() produces
a random value. /Ix
Capturing subpattern count = 1
Options: extended
First code unit = 'I'
Last code unit = 'e'
Subject length lower bound = 141

/^(?P<A>a) (?J:(?P<B>b)(?P<B>c)) (?P<C>d)/I
Capturing subpattern count = 4
Named capturing subpatterns:
  A   1
  B   2
  B   3
  C   4
Compile options: <none>
Overall options: anchored
Duplicate name status changes
Subject length lower bound = 6
    a bc d\=copy=A,copy=B,copy=C
 0: a bc d
 1: a
 2: b
 3: c
 4: d
  C a (1) A
  C b (1) B
  C d (1) C

/^(?P<A>a)?(?(A)a|b)/I
Capturing subpattern count = 1
Named capturing subpatterns:
  A   1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1
    aabc
 0: aa
 1: a
    bc
 0: b
    ** Failers
No match
    abc
No match

/(?:(?(ZZ)a|b)(?P<ZZ>X))+/I
Capturing subpattern count = 1
Named capturing subpatterns:
  ZZ   1
Last code unit = 'X'
Subject length lower bound = 2
    bXaX
 0: bXaX
 1: X

/(?:(?(2y)a|b)(X))+/I
Failed: error 126 at offset 7: malformed number or name after (?(

/(?:(?(ZA)a|b)(?P<ZZ>X))+/I
Failed: error 115 at offset 9: reference to non-existent subpattern

/(?:(?(ZZ)a|b)(?(ZZ)a|b)(?P<ZZ>X))+/I
Capturing subpattern count = 1
Named capturing subpatterns:
  ZZ   1
Last code unit = 'X'
Subject length lower bound = 3
    bbXaaX
 0: bbXaaX
 1: X

/(?:(?(ZZ)a|\(b\))\\(?P<ZZ>X))+/I
Capturing subpattern count = 1
Named capturing subpatterns:
  ZZ   1
Last code unit = 'X'
Subject length lower bound = 3
    (b)\\Xa\\X
 0: (b)\Xa\X
 1: X

/(?P<ABC/I
Failed: error 142 at offset 7: syntax error in subpattern name (missing terminator)

/(?:(?(A)(?P=A)a|b)(?P<A>X|Y))+/I
Capturing subpattern count = 1
Max back reference = 1
Named capturing subpatterns:
  A   1
Subject length lower bound = 2
    bXXaYYaY
 0: bXXaYYaY
 1: Y
    bXYaXXaX
 0: bX
 1: X

/()()()()()()()()()(?:(?(A)(?P=A)a|b)(?P<A>X|Y))+/I
Capturing subpattern count = 10
Max back reference = 10
Named capturing subpatterns:
  A  10
Subject length lower bound = 2
    bXXaYYaY
 0: bXXaYYaY
 1: 
 2: 
 3: 
 4: 
 5: 
 6: 
 7: 
 8: 
 9: 
10: Y

/\s*,\s*/I
Capturing subpattern count = 0
Starting code units: \x09 \x0a \x0b \x0c \x0d \x20 , 
Last code unit = ','
Subject length lower bound = 1
    \x0b,\x0b
 0: \x0b,\x0b
    \x0c,\x0d
 0: \x0c,\x0d

/^abc/Im
Capturing subpattern count = 0
Options: multiline
First code unit at start or follows newline
Last code unit = 'c'
Subject length lower bound = 3
    xyz\nabc
 0: abc
    xyz\nabc>\=newline=lf
 0: abc
    xyz\r\nabc>\=newline=lf
 0: abc
    xyz\rabc>\=newline=cr
 0: abc
    xyz\r\nabclf>\=newline=crlf
 0: abc
    ** Failers
No match
    xyz\nabc>\=newline=cr
No match
    xyz\r\nabc>\=newline=cr
No match
    xyz\nabclf>\=newline=crlf
No match
    xyz\rabclf>\=newline=crlf
No match
    xyz\rabc>\=newline=lf
No match

/abc$/Im,newline=lf
Capturing subpattern count = 0
Options: multiline
Forced newline is LF
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3
    xyzabc
 0: abc
    xyzabc\n
 0: abc
    xyzabc\npqr
 0: abc
    xyzabc\r>\=newline=cr
 0: abc
    xyzabc\rpqr>\=newline=cr
 0: abc
    xyzabc\r\nlf>\=newline=crlf
 0: abc
    xyzabc\r\npqrlf>\=newline=crlf
 0: abc
    ** Failers
No match
    xyzabc\r
No match
    xyzabc\rpqr
No match
    xyzabc\r\n
No match
    xyzabc\r\npqr
No match

/^abc/Im,newline=cr
Capturing subpattern count = 0
Options: multiline
Forced newline is CR
First code unit at start or follows newline
Last code unit = 'c'
Subject length lower bound = 3
    xyz\rabcdef
 0: abc
    xyz\nabcdef>\=newline=lf
 0: abc
    ** Failers
No match
    xyz\nabcdef
No match

/^abc/Im,newline=lf
Capturing subpattern count = 0
Options: multiline
Forced newline is LF
First code unit at start or follows newline
Last code unit = 'c'
Subject length lower bound = 3
    xyz\nabcdef
 0: abc
    xyz\rabcdef>\=newline=cr
 0: abc
    ** Failers
No match
    xyz\rabcdef
No match

/^abc/Im,newline=crlf
Capturing subpattern count = 0
Options: multiline
Forced newline is CRLF
First code unit at start or follows newline
Last code unit = 'c'
Subject length lower bound = 3
    xyz\r\nabcdef
 0: abc
    xyz\rabcdef>\=newline=cr
 0: abc
    ** Failers
No match
    xyz\rabcdef
No match

/^abc/Im,newline=bad
** Invalid value in 'newline=bad'

/abc/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3
    xyz\rabc\=newline=bad
** Invalid value in 'newline=bad'
    abc
 0: abc

/.*/I,newline=lf
Capturing subpattern count = 0
May match empty string
Forced newline is LF
First code unit at start or follows newline
Subject length lower bound = 0
    abc\ndef
 0: abc
    abc\rdef
 0: abc\x0ddef
    abc\r\ndef
 0: abc\x0d
    abc\ndef\=newline=cr
 0: abc\x0adef
    abc\rdef\=newline=cr
 0: abc
    abc\r\ndef\=newline=cr
 0: abc
    abc\ndef\=newline=crlf
 0: abc\x0adef
    abc\rdef\=newline=crlf
 0: abc\x0ddef
    abc\r\ndef\=newline=crlf
 0: abc

/\w+(.)(.)?def/Is
Capturing subpattern count = 2
Options: dotall
Starting code units: 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P 
  Q R S T U V W X Y Z _ a b c d e f g h i j k l m n o p q r s t u v w x y z 
Last code unit = 'f'
Subject length lower bound = 5
    abc\ndef
 0: abc\x0adef
 1: \x0a
    abc\rdef
 0: abc\x0ddef
 1: \x0d
    abc\r\ndef
 0: abc\x0d\x0adef
 1: \x0d
 2: \x0a

!((?:\s|//.*\\n|/[*](?:\\n|.)*?[*]/)*)!I
Capturing subpattern count = 1
May match empty string
Subject length lower bound = 0
   /* this is a C style comment */\=find_limits
Minimum match limit = 120
Minimum recursion limit = 6
 0: /* this is a C style comment */
 1: /* this is a C style comment */

/(?P<B>25[0-5]|2[0-4]\d|[01]?\d?\d)(?:\.(?P>B)){3}/I
Capturing subpattern count = 1
Named capturing subpatterns:
  B   1
Starting code units: 0 1 2 3 4 5 6 7 8 9 
Last code unit = '.'
Subject length lower bound = 7

/()()()()()()()()()()()()()()()()()()()()
 ()()()()()()()()()()()()()()()()()()()()
 ()()()()()()()()()()()()()()()()()()()()
 ()()()()()()()()()()()()()()()()()()()()
 ()()()()()()()()()()()()()()()()()()()()
 (.(.))/Ix
Capturing subpattern count = 102
Options: extended
Subject length lower bound = 2
    XY\=ovector=133
 0: XY
 1: 
 2: 
 3: 
 4: 
 5: 
 6: 
 7: 
 8: 
 9: 
10: 
11: 
12: 
13: 
14: 
15: 
16: 
17: 
18: 
19: 
20: 
21: 
22: 
23: 
24: 
25: 
26: 
27: 
28: 
29: 
30: 
31: 
32: 
33: 
34: 
35: 
36: 
37: 
38: 
39: 
40: 
41: 
42: 
43: 
44: 
45: 
46: 
47: 
48: 
49: 
50: 
51: 
52: 
53: 
54: 
55: 
56: 
57: 
58: 
59: 
60: 
61: 
62: 
63: 
64: 
65: 
66: 
67: 
68: 
69: 
70: 
71: 
72: 
73: 
74: 
75: 
76: 
77: 
78: 
79: 
80: 
81: 
82: 
83: 
84: 
85: 
86: 
87: 
88: 
89: 
90: 
91: 
92: 
93: 
94: 
95: 
96: 
97: 
98: 
99: 
100: 
101: XY
102: Y

/(a*b|(?i:c*(?-i)d))/I
Capturing subpattern count = 1
Starting code units: C a b c d 
Subject length lower bound = 1

/()[ab]xyz/I
Capturing subpattern count = 1
Starting code units: a b 
Last code unit = 'z'
Subject length lower bound = 4

/(|)[ab]xyz/I
Capturing subpattern count = 1
Starting code units: a b 
Last code unit = 'z'
Subject length lower bound = 4

/(|c)[ab]xyz/I
Capturing subpattern count = 1
Starting code units: a b c 
Last code unit = 'z'
Subject length lower bound = 4

/(|c?)[ab]xyz/I
Capturing subpattern count = 1
Starting code units: a b c 
Last code unit = 'z'
Subject length lower bound = 4

/(d?|c?)[ab]xyz/I
Capturing subpattern count = 1
Starting code units: a b c d 
Last code unit = 'z'
Subject length lower bound = 4

/(d?|c)[ab]xyz/I
Capturing subpattern count = 1
Starting code units: a b c d 
Last code unit = 'z'
Subject length lower bound = 4

/^a*b\d/IB
------------------------------------------------------------------
        Bra
        ^
        a*+
        b
        \d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Last code unit = 'b'
Subject length lower bound = 2

/^a*+b\d/IB
------------------------------------------------------------------
        Bra
        ^
        a*+
        b
        \d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Last code unit = 'b'
Subject length lower bound = 2

/^a*?b\d/IB
------------------------------------------------------------------
        Bra
        ^
        a*+
        b
        \d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Last code unit = 'b'
Subject length lower bound = 2

/^a+A\d/IB
------------------------------------------------------------------
        Bra
        ^
        a++
        A
        \d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Last code unit = 'A'
Subject length lower bound = 3
    aaaA5
 0: aaaA5
    ** Failers
No match
    aaaa5
No match

/^a*A\d/IBi
------------------------------------------------------------------
        Bra
        ^
     /i a*
     /i A
        \d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: caseless
Overall options: anchored caseless
Last code unit = 'A' (caseless)
Subject length lower bound = 2
    aaaA5
 0: aaaA5
    aaaa5
 0: aaaa5

/(a*|b*)[cd]/I
Capturing subpattern count = 1
Starting code units: a b c d 
Subject length lower bound = 1

/(a+|b*)[cd]/I
Capturing subpattern count = 1
Starting code units: a b c d 
Subject length lower bound = 1

/(a*|b+)[cd]/I
Capturing subpattern count = 1
Starting code units: a b c d 
Subject length lower bound = 1

/(a+|b+)[cd]/I
Capturing subpattern count = 1
Starting code units: a b 
Subject length lower bound = 2

/((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((
 ((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((
 (((
 a
 ))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))
 ))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))
 )))
/Ix
Capturing subpattern count = 203
Options: extended
First code unit = 'a'
Subject length lower bound = 1
  large nest
Matched, but too many substrings
 0: a
 1: a
 2: a
 3: a
 4: a
 5: a
 6: a
 7: a
 8: a
 9: a
10: a
11: a
12: a
13: a
14: a

/a*\d/B
------------------------------------------------------------------
        Bra
        a*+
        \d
        Ket
        End
------------------------------------------------------------------

/a*\D/B
------------------------------------------------------------------
        Bra
        a*
        \D
        Ket
        End
------------------------------------------------------------------

/0*\d/B
------------------------------------------------------------------
        Bra
        0*
        \d
        Ket
        End
------------------------------------------------------------------

/0*\D/B
------------------------------------------------------------------
        Bra
        0*+
        \D
        Ket
        End
------------------------------------------------------------------

/a*\s/B
------------------------------------------------------------------
        Bra
        a*+
        \s
        Ket
        End
------------------------------------------------------------------

/a*\S/B
------------------------------------------------------------------
        Bra
        a*
        \S
        Ket
        End
------------------------------------------------------------------

/ *\s/B
------------------------------------------------------------------
        Bra
         *
        \s
        Ket
        End
------------------------------------------------------------------

/ *\S/B
------------------------------------------------------------------
        Bra
         *+
        \S
        Ket
        End
------------------------------------------------------------------

/a*\w/B
------------------------------------------------------------------
        Bra
        a*
        \w
        Ket
        End
------------------------------------------------------------------

/a*\W/B
------------------------------------------------------------------
        Bra
        a*+
        \W
        Ket
        End
------------------------------------------------------------------

/=*\w/B
------------------------------------------------------------------
        Bra
        =*+
        \w
        Ket
        End
------------------------------------------------------------------

/=*\W/B
------------------------------------------------------------------
        Bra
        =*
        \W
        Ket
        End
------------------------------------------------------------------

/\d*a/B
------------------------------------------------------------------
        Bra
        \d*+
        a
        Ket
        End
------------------------------------------------------------------

/\d*2/B
------------------------------------------------------------------
        Bra
        \d*
        2
        Ket
        End
------------------------------------------------------------------

/\d*\d/B
------------------------------------------------------------------
        Bra
        \d*
        \d
        Ket
        End
------------------------------------------------------------------

/\d*\D/B
------------------------------------------------------------------
        Bra
        \d*+
        \D
        Ket
        End
------------------------------------------------------------------

/\d*\s/B
------------------------------------------------------------------
        Bra
        \d*+
        \s
        Ket
        End
------------------------------------------------------------------

/\d*\S/B
------------------------------------------------------------------
        Bra
        \d*
        \S
        Ket
        End
------------------------------------------------------------------

/\d*\w/B
------------------------------------------------------------------
        Bra
        \d*
        \w
        Ket
        End
------------------------------------------------------------------

/\d*\W/B
------------------------------------------------------------------
        Bra
        \d*+
        \W
        Ket
        End
------------------------------------------------------------------

/\D*a/B
------------------------------------------------------------------
        Bra
        \D*
        a
        Ket
        End
------------------------------------------------------------------

/\D*2/B
------------------------------------------------------------------
        Bra
        \D*+
        2
        Ket
        End
------------------------------------------------------------------

/\D*\d/B
------------------------------------------------------------------
        Bra
        \D*+
        \d
        Ket
        End
------------------------------------------------------------------

/\D*\D/B
------------------------------------------------------------------
        Bra
        \D*
        \D
        Ket
        End
------------------------------------------------------------------

/\D*\s/B
------------------------------------------------------------------
        Bra
        \D*
        \s
        Ket
        End
------------------------------------------------------------------

/\D*\S/B
------------------------------------------------------------------
        Bra
        \D*
        \S
        Ket
        End
------------------------------------------------------------------

/\D*\w/B
------------------------------------------------------------------
        Bra
        \D*
        \w
        Ket
        End
------------------------------------------------------------------

/\D*\W/B
------------------------------------------------------------------
        Bra
        \D*
        \W
        Ket
        End
------------------------------------------------------------------

/\s*a/B
------------------------------------------------------------------
        Bra
        \s*+
        a
        Ket
        End
------------------------------------------------------------------

/\s*2/B
------------------------------------------------------------------
        Bra
        \s*+
        2
        Ket
        End
------------------------------------------------------------------

/\s*\d/B
------------------------------------------------------------------
        Bra
        \s*+
        \d
        Ket
        End
------------------------------------------------------------------

/\s*\D/B
------------------------------------------------------------------
        Bra
        \s*
        \D
        Ket
        End
------------------------------------------------------------------

/\s*\s/B
------------------------------------------------------------------
        Bra
        \s*
        \s
        Ket
        End
------------------------------------------------------------------

/\s*\S/B
------------------------------------------------------------------
        Bra
        \s*+
        \S
        Ket
        End
------------------------------------------------------------------

/\s*\w/B
------------------------------------------------------------------
        Bra
        \s*+
        \w
        Ket
        End
------------------------------------------------------------------

/\s*\W/B
------------------------------------------------------------------
        Bra
        \s*
        \W
        Ket
        End
------------------------------------------------------------------

/\S*a/B
------------------------------------------------------------------
        Bra
        \S*
        a
        Ket
        End
------------------------------------------------------------------

/\S*2/B
------------------------------------------------------------------
        Bra
        \S*
        2
        Ket
        End
------------------------------------------------------------------

/\S*\d/B
------------------------------------------------------------------
        Bra
        \S*
        \d
        Ket
        End
------------------------------------------------------------------

/\S*\D/B
------------------------------------------------------------------
        Bra
        \S*
        \D
        Ket
        End
------------------------------------------------------------------

/\S*\s/B
------------------------------------------------------------------
        Bra
        \S*+
        \s
        Ket
        End
------------------------------------------------------------------

/\S*\S/B
------------------------------------------------------------------
        Bra
        \S*
        \S
        Ket
        End
------------------------------------------------------------------

/\S*\w/B
------------------------------------------------------------------
        Bra
        \S*
        \w
        Ket
        End
------------------------------------------------------------------

/\S*\W/B
------------------------------------------------------------------
        Bra
        \S*
        \W
        Ket
        End
------------------------------------------------------------------

/\w*a/B
------------------------------------------------------------------
        Bra
        \w*
        a
        Ket
        End
------------------------------------------------------------------

/\w*2/B
------------------------------------------------------------------
        Bra
        \w*
        2
        Ket
        End
------------------------------------------------------------------

/\w*\d/B
------------------------------------------------------------------
        Bra
        \w*
        \d
        Ket
        End
------------------------------------------------------------------

/\w*\D/B
------------------------------------------------------------------
        Bra
        \w*
        \D
        Ket
        End
------------------------------------------------------------------

/\w*\s/B
------------------------------------------------------------------
        Bra
        \w*+
        \s
        Ket
        End
------------------------------------------------------------------

/\w*\S/B
------------------------------------------------------------------
        Bra
        \w*
        \S
        Ket
        End
------------------------------------------------------------------

/\w*\w/B
------------------------------------------------------------------
        Bra
        \w*
        \w
        Ket
        End
------------------------------------------------------------------

/\w*\W/B
------------------------------------------------------------------
        Bra
        \w*+
        \W
        Ket
        End
------------------------------------------------------------------

/\W*a/B
------------------------------------------------------------------
        Bra
        \W*+
        a
        Ket
        End
------------------------------------------------------------------

/\W*2/B
------------------------------------------------------------------
        Bra
        \W*+
        2
        Ket
        End
------------------------------------------------------------------

/\W*\d/B
------------------------------------------------------------------
        Bra
        \W*+
        \d
        Ket
        End
------------------------------------------------------------------

/\W*\D/B
------------------------------------------------------------------
        Bra
        \W*
        \D
        Ket
        End
------------------------------------------------------------------

/\W*\s/B
------------------------------------------------------------------
        Bra
        \W*
        \s
        Ket
        End
------------------------------------------------------------------

/\W*\S/B
------------------------------------------------------------------
        Bra
        \W*
        \S
        Ket
        End
------------------------------------------------------------------

/\W*\w/B
------------------------------------------------------------------
        Bra
        \W*+
        \w
        Ket
        End
------------------------------------------------------------------

/\W*\W/B
------------------------------------------------------------------
        Bra
        \W*
        \W
        Ket
        End
------------------------------------------------------------------

/[^a]+a/B
------------------------------------------------------------------
        Bra
        [^a]++
        a
        Ket
        End
------------------------------------------------------------------

/[^a]+a/Bi
------------------------------------------------------------------
        Bra
     /i [^a]++
     /i a
        Ket
        End
------------------------------------------------------------------

/[^a]+A/Bi
------------------------------------------------------------------
        Bra
     /i [^a]++
     /i A
        Ket
        End
------------------------------------------------------------------

/[^a]+b/B
------------------------------------------------------------------
        Bra
        [^a]+
        b
        Ket
        End
------------------------------------------------------------------

/[^a]+\d/B
------------------------------------------------------------------
        Bra
        [^a]+
        \d
        Ket
        End
------------------------------------------------------------------

/a*[^a]/B
------------------------------------------------------------------
        Bra
        a*+
        [^a]
        Ket
        End
------------------------------------------------------------------

/(?P<abc>x)(?P<xyz>y)/I
Capturing subpattern count = 2
Named capturing subpatterns:
  abc   1
  xyz   2
First code unit = 'x'
Last code unit = 'y'
Subject length lower bound = 2
    xy\=copy=abc,copy=xyz
 0: xy
 1: x
 2: y
  C x (1) abc
  C y (1) xyz

/(?<abc>x)(?'xyz'y)/I
Capturing subpattern count = 2
Named capturing subpatterns:
  abc   1
  xyz   2
First code unit = 'x'
Last code unit = 'y'
Subject length lower bound = 2
    xy\=copy=abc,copy=xyz
 0: xy
 1: x
 2: y
  C x (1) abc
  C y (1) xyz

/(?<abc'x)(?'xyz'y)/I
Failed: error 142 at offset 6: syntax error in subpattern name (missing terminator)

/(?<abc>x)(?'xyz>y)/I
Failed: error 142 at offset 15: syntax error in subpattern name (missing terminator)

/(?P'abc'x)(?P<xyz>y)/I
Failed: error 141 at offset 3: unrecognized character after (?P

/^(?:(?(ZZ)a|b)(?<ZZ>X))+/
    bXaX
 0: bXaX
 1: X
    bXbX
 0: bX
 1: X
    ** Failers
No match
    aXaX
No match
    aXbX
No match

/^(?P>abc)(?<abcd>xxx)/
Failed: error 115 at offset 8: reference to non-existent subpattern

/^(?P>abc)(?<abc>x|y)/
    xx
 0: xx
 1: x
    xy
 0: xy
 1: y
    yy
 0: yy
 1: y
    yx
 0: yx
 1: x

/^(?P>abc)(?P<abc>x|y)/
    xx
 0: xx
 1: x
    xy
 0: xy
 1: y
    yy
 0: yy
 1: y
    yx
 0: yx
 1: x

/^((?(abc)a|b)(?<abc>x|y))+/
    bxay
 0: bxay
 1: ay
 2: y
    bxby
 0: bx
 1: bx
 2: x
    ** Failers
No match
    axby
No match

/^(((?P=abc)|X)(?<abc>x|y))+/
    XxXxxx
 0: XxXxxx
 1: xx
 2: x
 3: x
    XxXyyx
 0: XxXyyx
 1: yx
 2: y
 3: x
    XxXyxx
 0: XxXy
 1: Xy
 2: X
 3: y
    ** Failers
No match
    x
No match

/^(?1)(abc)/
    abcabc
 0: abcabc
 1: abc

/^(?:(?:\1|X)(a|b))+/
    Xaaa
 0: Xaaa
 1: a
    Xaba
 0: Xa
 1: a

/^[\E\Qa\E-\Qz\E]+/B
------------------------------------------------------------------
        Bra
        ^
        [a-z]++
        Ket
        End
------------------------------------------------------------------

/^[a\Q]bc\E]/B
------------------------------------------------------------------
        Bra
        ^
        [\]a-c]
        Ket
        End
------------------------------------------------------------------

/^[a-\Q\E]/B
------------------------------------------------------------------
        Bra
        ^
        [\-a]
        Ket
        End
------------------------------------------------------------------

/^(?P>abc)[()](?<abc>)/B
------------------------------------------------------------------
        Bra
        ^
        Recurse
        [()]
        CBra 1
        Ket
        Ket
        End
------------------------------------------------------------------

/^((?(abc)y)[()](?P<abc>x))+/B
------------------------------------------------------------------
        Bra
        ^
        CBra 1
        Cond
      2 Cond ref
        y
        Ket
        [()]
        CBra 2
        x
        Ket
        KetRmax
        Ket
        End
------------------------------------------------------------------
    (xy)x
 0: (xy)x
 1: y)x
 2: x

/^(?P>abc)\Q()\E(?<abc>)/B
------------------------------------------------------------------
        Bra
        ^
        Recurse
        ()
        CBra 1
        Ket
        Ket
        End
------------------------------------------------------------------

/^(?P>abc)[a\Q(]\E(](?<abc>)/B
------------------------------------------------------------------
        Bra
        ^
        Recurse
        [(\]a]
        CBra 1
        Ket
        Ket
        End
------------------------------------------------------------------

/^(?P>abc) # this is (a comment)
  (?<abc>)/Bx
------------------------------------------------------------------
        Bra
        ^
        Recurse
        CBra 1
        Ket
        Ket
        End
------------------------------------------------------------------

/^\W*(?:(?<one>(?<two>.)\W*(?&one)\W*\k<two>|)|(?<three>(?<four>.)\W*(?&three)\W*\k'four'|\W*.\W*))\W*$/Ii
Capturing subpattern count = 4
Max back reference = 4
Named capturing subpatterns:
  four    4
  one     1
  three   3
  two     2
May match empty string
Compile options: caseless
Overall options: anchored caseless
Subject length lower bound = 0
    1221
 0: 1221
 1: 1221
 2: 1
    Satan, oscillate my metallic sonatas!
 0: Satan, oscillate my metallic sonatas!
 1: <unset>
 2: <unset>
 3: Satan, oscillate my metallic sonatas
 4: S
    A man, a plan, a canal: Panama!
 0: A man, a plan, a canal: Panama!
 1: <unset>
 2: <unset>
 3: A man, a plan, a canal: Panama
 4: A
    Able was I ere I saw Elba.
 0: Able was I ere I saw Elba.
 1: <unset>
 2: <unset>
 3: Able was I ere I saw Elba
 4: A
    *** Failers
No match
    The quick brown fox
No match

/(?=(\w+))\1:/I
Capturing subpattern count = 1
Max back reference = 1
Starting code units: 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P 
  Q R S T U V W X Y Z _ a b c d e f g h i j k l m n o p q r s t u v w x y z 
Last code unit = ':'
Subject length lower bound = 2
    abcd:
 0: abcd:
 1: abcd

/(?=(?'abc'\w+))\k<abc>:/I
Capturing subpattern count = 1
Max back reference = 1
Named capturing subpatterns:
  abc   1
Starting code units: 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P 
  Q R S T U V W X Y Z _ a b c d e f g h i j k l m n o p q r s t u v w x y z 
Last code unit = ':'
Subject length lower bound = 2
    abcd:
 0: abcd:
 1: abcd

/(?'abc'a|b)(?<abc>d|e)\k<abc>{2}/dupnames
    adaa
 0: adaa
 1: a
 2: d
    ** Failers
No match
    addd
No match
    adbb
No match

/(?'abc'a|b)(?<abc>d|e)(?&abc){2}/dupnames
    bdaa
 0: bdaa
 1: b
 2: d
    bdab
 0: bdab
 1: b
 2: d
    ** Failers
No match
    bddd
No match

/(?(<bc))/
Failed: error 126 at offset 6: malformed number or name after (?(

/(?(''))/
Failed: error 128 at offset 4: assertion expected after (?(

/(?('R')stuff)/
Failed: error 115 at offset 7: reference to non-existent subpattern

/((abc (?(R) (?(R1)1) (?(R2)2) X  |  (?1)  (?2)   (?R) ))) /x
    abcabc1Xabc2XabcXabcabc
 0: abcabc1Xabc2XabcX
 1: abcabc1Xabc2XabcX
 2: abcabc1Xabc2XabcX

/(?<A> (?'B' abc (?(R) (?(R&A)1) (?(R&B)2) X  |  (?1)  (?2)   (?R) ))) /x
    abcabc1Xabc2XabcXabcabc
 0: abcabc1Xabc2XabcX
 1: abcabc1Xabc2XabcX
 2: abcabc1Xabc2XabcX

/(?<A> (?'B' abc (?(R) (?(R&C)1) (?(R&B)2) X  |  (?1)  (?2)   (?R) ))) /x
Failed: error 115 at offset 29: reference to non-existent subpattern

/^(?(DEFINE) abc | xyz ) /x
Failed: error 154 at offset 22: DEFINE group contains more than one branch

/(?(DEFINE) abc) xyz/Ix
Capturing subpattern count = 0
Options: extended
First code unit = 'x'
Last code unit = 'z'
Subject length lower bound = 3

/(a|)*\d/
  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\=ovector=0
No match
  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa4\=ovector=0
Matched, but too many substrings

/^a.b/newline=lf
    a\rb
 0: a\x0db
    a\nb>\=newline=cr
 0: a\x0ab
    a\x85b>\=newline=anycrlf
 0: a\x85b
    ** Failers
No match
    a\nb
No match
    a\nb\=newline=any
No match
    a\rb>\=newline=cr
No match
    a\rb\=newline=any
No match
    a\x85b\=newline=any
No match
    a\rb>\=newline=anycrlf
No match

/^abc./gmx,newline=any
    abc1 \x0aabc2 \x0babc3xx \x0cabc4 \x0dabc5xx \x0d\x0aabc6 \x85abc7 JUNK
 0: abc1
 0: abc2
 0: abc3
 0: abc4
 0: abc5
 0: abc6
 0: abc7

/abc.$/gmx,newline=any
    abc1\x0a abc2\x0b abc3\x0c abc4\x0d abc5\x0d\x0a abc6\x85 abc7 abc9
 0: abc1
 0: abc2
 0: abc3
 0: abc4
 0: abc5
 0: abc6
 0: abc9

/^a\Rb/bsr=unicode
    a\nb
 0: a\x0ab
    a\rb
 0: a\x0db
    a\r\nb
 0: a\x0d\x0ab
    a\x0bb
 0: a\x0bb
    a\x0cb
 0: a\x0cb
    a\x85b
 0: a\x85b
    ** Failers
No match
    a\n\rb
No match

/^a\R*b/bsr=unicode
    ab
 0: ab
    a\nb
 0: a\x0ab
    a\rb
 0: a\x0db
    a\r\nb
 0: a\x0d\x0ab
    a\x0bb
 0: a\x0bb
    a\x0cb
 0: a\x0cb
    a\x85b
 0: a\x85b
    a\n\rb
 0: a\x0a\x0db
    a\n\r\x85\x0cb
 0: a\x0a\x0d\x85\x0cb

/^a\R+b/bsr=unicode
    a\nb
 0: a\x0ab
    a\rb
 0: a\x0db
    a\r\nb
 0: a\x0d\x0ab
    a\x0bb
 0: a\x0bb
    a\x0cb
 0: a\x0cb
    a\x85b
 0: a\x85b
    a\n\rb
 0: a\x0a\x0db
    a\n\r\x85\x0cb
 0: a\x0a\x0d\x85\x0cb
    ** Failers
No match
    ab
No match

/^a\R{1,3}b/bsr=unicode
    a\nb
 0: a\x0ab
    a\n\rb
 0: a\x0a\x0db
    a\n\r\x85b
 0: a\x0a\x0d\x85b
    a\r\n\r\nb
 0: a\x0d\x0a\x0d\x0ab
    a\r\n\r\n\r\nb
 0: a\x0d\x0a\x0d\x0a\x0d\x0ab
    a\n\r\n\rb
 0: a\x0a\x0d\x0a\x0db
    a\n\n\r\nb
 0: a\x0a\x0a\x0d\x0ab
    ** Failers
No match
    a\n\n\n\rb
No match
    a\r
No match

/(?&abc)X(?<abc>P)/I
Capturing subpattern count = 1
Named capturing subpatterns:
  abc   1
Last code unit = 'P'
Subject length lower bound = 3
    abcPXP123
 0: PXP
 1: P

/(?1)X(?<abc>P)/I
Capturing subpattern count = 1
Named capturing subpatterns:
  abc   1
Last code unit = 'P'
Subject length lower bound = 3
    abcPXP123
 0: PXP
 1: P

/(?:a(?&abc)b)*(?<abc>x)/
    123axbaxbaxbx456
 0: axbaxbaxbx
 1: x
    123axbaxbaxb456
 0: x
 1: x

/(?:a(?&abc)b){1,5}(?<abc>x)/
    123axbaxbaxbx456
 0: axbaxbaxbx
 1: x

/(?:a(?&abc)b){2,5}(?<abc>x)/
    123axbaxbaxbx456
 0: axbaxbaxbx
 1: x

/(?:a(?&abc)b){2,}(?<abc>x)/
    123axbaxbaxbx456
 0: axbaxbaxbx
 1: x

/(abc)(?i:(?1))/
   defabcabcxyz
 0: abcabc
 1: abc
   DEFabcABCXYZ
No match

/(abc)(?:(?i)(?1))/
   defabcabcxyz
 0: abcabc
 1: abc
   DEFabcABCXYZ
No match

/^(a)\g-2/
Failed: error 115 at offset 7: reference to non-existent subpattern

/^(a)\g/
Failed: error 158 at offset 5: a numbered reference must not be zero

/^(a)\g{0}/
Failed: error 158 at offset 8: a numbered reference must not be zero

/^(a)\g{3/
Failed: error 157 at offset 8: \g is not followed by a braced, angle-bracketed, or quoted name/number or by a plain number

/^(a)\g{aa}/
Failed: error 115 at offset 9: reference to non-existent subpattern

/^a.b/newline=lf
    a\rb
 0: a\x0db
    *** Failers
No match
    a\nb
No match

/.+foo/
    afoo
 0: afoo
    ** Failers
No match
    \r\nfoo
No match
    \nfoo
No match

/.+foo/newline=crlf
    afoo
 0: afoo
    \nfoo
 0: \x0afoo
    ** Failers
No match
    \r\nfoo
No match

/.+foo/newline=any
    afoo
 0: afoo
    ** Failers
No match
    \nfoo
No match
    \r\nfoo
No match

/.+foo/s
    afoo
 0: afoo
    \r\nfoo
 0: \x0d\x0afoo
    \nfoo
 0: \x0afoo
    
/^$/gm,newline=any
    abc\r\rxyz
 0: 
    abc\n\rxyz  
 0: 
    ** Failers 
No match
    abc\r\nxyz
No match

/(?m)^$/g,newline=any,aftertext
    abc\r\n\r\n
 0: 
 0+ \x0d\x0a

/(?m)^$|^\r\n/g,newline=any,aftertext
    abc\r\n\r\n
 0: 
 0+ \x0d\x0a
 0: \x0d\x0a
 0+ 
    
/(?m)$/g,newline=any,aftertext
    abc\r\n\r\n
 0: 
 0+ \x0d\x0a\x0d\x0a
 0: 
 0+ \x0d\x0a
 0: 
 0+ 

/abc.$/gmx,newline=anycrlf
    abc1\x0a abc2\x0b abc3\x0c abc4\x0d abc5\x0d\x0a abc6\x85 abc9
 0: abc1
 0: abc4
 0: abc5
 0: abc9

/^X/m
    XABC
 0: X
    ** Failers 
No match
    XABC\=notbol
No match

/(ab|c)(?-1)/B
------------------------------------------------------------------
        Bra
        CBra 1
        ab
        Alt
        c
        Ket
        Recurse
        Ket
        End
------------------------------------------------------------------
    abc
 0: abc
 1: ab

/xy(?+1)(abc)/B
------------------------------------------------------------------
        Bra
        xy
        Recurse
        CBra 1
        abc
        Ket
        Ket
        End
------------------------------------------------------------------
    xyabcabc
 0: xyabcabc
 1: abc
    ** Failers
No match
    xyabc  
No match
    
/x(?-0)y/
Failed: error 158 at offset 5: a numbered reference must not be zero

/x(?-1)y/
Failed: error 115 at offset 5: reference to non-existent subpattern

/x(?+0)y/
Failed: error 158 at offset 5: a numbered reference must not be zero

/x(?+1)y/
Failed: error 115 at offset 5: reference to non-existent subpattern

/^(abc)?(?(-1)X|Y)/B
------------------------------------------------------------------
        Bra
        ^
        Brazero
        CBra 1
        abc
        Ket
        Cond
      1 Cond ref
        X
        Alt
        Y
        Ket
        Ket
        End
------------------------------------------------------------------
    abcX
 0: abcX
 1: abc
    Y
 0: Y
    ** Failers
No match
    abcY   
No match
    
/^((?(+1)X|Y)(abc))+/B
------------------------------------------------------------------
        Bra
        ^
        CBra 1
        Cond
      2 Cond ref
        X
        Alt
        Y
        Ket
        CBra 2
        abc
        Ket
        KetRmax
        Ket
        End
------------------------------------------------------------------
    YabcXabc
 0: YabcXabc
 1: Xabc
 2: abc
    YabcXabcXabc
 0: YabcXabcXabc
 1: Xabc
 2: abc
    ** Failers
No match
    XabcXabc  
No match

/(?(-1)a)/B
Failed: error 115 at offset 6: reference to non-existent subpattern

/((?(-1)a))/B
------------------------------------------------------------------
        Bra
        CBra 1
        Cond
      1 Cond ref
        a
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------

/((?(-2)a))/B
Failed: error 115 at offset 7: reference to non-existent subpattern

/^(?(+1)X|Y)(.)/B
------------------------------------------------------------------
        Bra
        ^
        Cond
      1 Cond ref
        X
        Alt
        Y
        Ket
        CBra 1
        Any
        Ket
        Ket
        End
------------------------------------------------------------------
    Y!
 0: Y!
 1: !

/(?<A>tom|bon)-\k{A}/
    tom-tom
 0: tom-tom
 1: tom
    bon-bon 
 0: bon-bon
 1: bon
    ** Failers
No match
    tom-bon  
No match

/\g{A/
Failed: error 142 at offset 4: syntax error in subpattern name (missing terminator)

/(?|(abc)|(xyz))/B
------------------------------------------------------------------
        Bra
        Bra
        CBra 1
        abc
        Ket
        Alt
        CBra 1
        xyz
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------
   >abc<
 0: abc
 1: abc
   >xyz< 
 0: xyz
 1: xyz

/(x)(?|(abc)|(xyz))(x)/B
------------------------------------------------------------------
        Bra
        CBra 1
        x
        Ket
        Bra
        CBra 2
        abc
        Ket
        Alt
        CBra 2
        xyz
        Ket
        Ket
        CBra 3
        x
        Ket
        Ket
        End
------------------------------------------------------------------
    xabcx
 0: xabcx
 1: x
 2: abc
 3: x
    xxyzx 
 0: xxyzx
 1: x
 2: xyz
 3: x

/(x)(?|(abc)(pqr)|(xyz))(x)/B
------------------------------------------------------------------
        Bra
        CBra 1
        x
        Ket
        Bra
        CBra 2
        abc
        Ket
        CBra 3
        pqr
        Ket
        Alt
        CBra 2
        xyz
        Ket
        Ket
        CBra 4
        x
        Ket
        Ket
        End
------------------------------------------------------------------
    xabcpqrx
 0: xabcpqrx
 1: x
 2: abc
 3: pqr
 4: x
    xxyzx 
 0: xxyzx
 1: x
 2: xyz
 3: <unset>
 4: x

/\H++X/B
------------------------------------------------------------------
        Bra
        \H++
        X
        Ket
        End
------------------------------------------------------------------
    ** Failers
No match
    XXXX
No match
    
/\H+\hY/B
------------------------------------------------------------------
        Bra
        \H++
        \h
        Y
        Ket
        End
------------------------------------------------------------------
    XXXX Y 
 0: XXXX Y

/\H+ Y/B
------------------------------------------------------------------
        Bra
        \H++
         Y
        Ket
        End
------------------------------------------------------------------

/\h+A/B
------------------------------------------------------------------
        Bra
        \h++
        A
        Ket
        End
------------------------------------------------------------------

/\v*B/B
------------------------------------------------------------------
        Bra
        \v*+
        B
        Ket
        End
------------------------------------------------------------------

/\V+\x0a/B
------------------------------------------------------------------
        Bra
        \V++
        \x0a
        Ket
        End
------------------------------------------------------------------

/A+\h/B
------------------------------------------------------------------
        Bra
        A++
        \h
        Ket
        End
------------------------------------------------------------------

/ *\H/B
------------------------------------------------------------------
        Bra
         *+
        \H
        Ket
        End
------------------------------------------------------------------

/A*\v/B
------------------------------------------------------------------
        Bra
        A*+
        \v
        Ket
        End
------------------------------------------------------------------

/\x0b*\V/B
------------------------------------------------------------------
        Bra
        \x0b*+
        \V
        Ket
        End
------------------------------------------------------------------

/\d+\h/B
------------------------------------------------------------------
        Bra
        \d++
        \h
        Ket
        End
------------------------------------------------------------------

/\d*\v/B
------------------------------------------------------------------
        Bra
        \d*+
        \v
        Ket
        End
------------------------------------------------------------------

/S+\h\S+\v/B
------------------------------------------------------------------
        Bra
        S++
        \h
        \S++
        \v
        Ket
        End
------------------------------------------------------------------

/\w{3,}\h\w+\v/B
------------------------------------------------------------------
        Bra
        \w{3}
        \w*+
        \h
        \w++
        \v
        Ket
        End
------------------------------------------------------------------

/\h+\d\h+\w\h+\S\h+\H/B
------------------------------------------------------------------
        Bra
        \h++
        \d
        \h++
        \w
        \h++
        \S
        \h++
        \H
        Ket
        End
------------------------------------------------------------------

/\v+\d\v+\w\v+\S\v+\V/B
------------------------------------------------------------------
        Bra
        \v++
        \d
        \v++
        \w
        \v++
        \S
        \v++
        \V
        Ket
        End
------------------------------------------------------------------

/\H+\h\H+\d/B
------------------------------------------------------------------
        Bra
        \H++
        \h
        \H+
        \d
        Ket
        End
------------------------------------------------------------------

/\V+\v\V+\w/B
------------------------------------------------------------------
        Bra
        \V++
        \v
        \V+
        \w
        Ket
        End
------------------------------------------------------------------

/\( (?: [^()]* | (?R) )* \)/x
(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(00)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)\=jitstack=1024
 0: (0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(0(00)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)0)

/[\E]AAA/
Failed: error 106 at offset 7: missing terminating ] for character class

/[\Q\E]AAA/
Failed: error 106 at offset 9: missing terminating ] for character class

/[^\E]AAA/
Failed: error 106 at offset 8: missing terminating ] for character class

/[^\Q\E]AAA/
Failed: error 106 at offset 10: missing terminating ] for character class

/[\E^]AAA/
Failed: error 106 at offset 8: missing terminating ] for character class

/[\Q\E^]AAA/
Failed: error 106 at offset 10: missing terminating ] for character class

/A(*PRUNE)B(*SKIP)C(*THEN)D(*COMMIT)E(*F)F(*FAIL)G(?!)H(*ACCEPT)I/B
------------------------------------------------------------------
        Bra
        A
        *PRUNE
        B
        *SKIP
        C
        *THEN
        D
        *COMMIT
        E
        *FAIL
        F
        *FAIL
        G
        *FAIL
        H
        *ACCEPT
        I
        Ket
        End
------------------------------------------------------------------

/^a+(*FAIL)/auto_callout
    aaaaaa
--->aaaaaa
 +0 ^          ^
 +1 ^          a+
 +3 ^     ^    (*FAIL)
 +3 ^    ^     (*FAIL)
 +3 ^   ^      (*FAIL)
 +3 ^  ^       (*FAIL)
 +3 ^ ^        (*FAIL)
 +3 ^^         (*FAIL)
No match
    
/a+b?c+(*FAIL)/auto_callout
    aaabccc
--->aaabccc
 +0 ^           a+
 +2 ^  ^        b?
 +4 ^   ^       c+
 +6 ^      ^    (*FAIL)
 +6 ^     ^     (*FAIL)
 +6 ^    ^      (*FAIL)
 +0  ^          a+
 +2  ^ ^        b?
 +4  ^  ^       c+
 +6  ^     ^    (*FAIL)
 +6  ^    ^     (*FAIL)
 +6  ^   ^      (*FAIL)
 +0   ^         a+
 +2   ^^        b?
 +4   ^ ^       c+
 +6   ^    ^    (*FAIL)
 +6   ^   ^     (*FAIL)
 +6   ^  ^      (*FAIL)
No match

/a+b?(*PRUNE)c+(*FAIL)/auto_callout
    aaabccc
--->aaabccc
 +0 ^           a+
 +2 ^  ^        b?
 +4 ^   ^       (*PRUNE)
+12 ^   ^       c+
+14 ^      ^    (*FAIL)
+14 ^     ^     (*FAIL)
+14 ^    ^      (*FAIL)
 +0  ^          a+
 +2  ^ ^        b?
 +4  ^  ^       (*PRUNE)
+12  ^  ^       c+
+14  ^     ^    (*FAIL)
+14  ^    ^     (*FAIL)
+14  ^   ^      (*FAIL)
 +0   ^         a+
 +2   ^^        b?
 +4   ^ ^       (*PRUNE)
+12   ^ ^       c+
+14   ^    ^    (*FAIL)
+14   ^   ^     (*FAIL)
+14   ^  ^      (*FAIL)
No match

/a+b?(*COMMIT)c+(*FAIL)/auto_callout
    aaabccc
--->aaabccc
 +0 ^           a+
 +2 ^  ^        b?
 +4 ^   ^       (*COMMIT)
+13 ^   ^       c+
+15 ^      ^    (*FAIL)
+15 ^     ^     (*FAIL)
+15 ^    ^      (*FAIL)
No match
    
/a+b?(*SKIP)c+(*FAIL)/auto_callout
    aaabcccaaabccc
--->aaabcccaaabccc
 +0 ^                  a+
 +2 ^  ^               b?
 +4 ^   ^              (*SKIP)
+11 ^   ^              c+
+13 ^      ^           (*FAIL)
+13 ^     ^            (*FAIL)
+13 ^    ^             (*FAIL)
 +0        ^           a+
 +2        ^  ^        b?
 +4        ^   ^       (*SKIP)
+11        ^   ^       c+
+13        ^      ^    (*FAIL)
+13        ^     ^     (*FAIL)
+13        ^    ^      (*FAIL)
No match

/a+b?(*THEN)c+(*FAIL)/auto_callout
    aaabccc
--->aaabccc
 +0 ^           a+
 +2 ^  ^        b?
 +4 ^   ^       (*THEN)
+11 ^   ^       c+
+13 ^      ^    (*FAIL)
+13 ^     ^     (*FAIL)
+13 ^    ^      (*FAIL)
 +0  ^          a+
 +2  ^ ^        b?
 +4  ^  ^       (*THEN)
+11  ^  ^       c+
+13  ^     ^    (*FAIL)
+13  ^    ^     (*FAIL)
+13  ^   ^      (*FAIL)
 +0   ^         a+
 +2   ^^        b?
 +4   ^ ^       (*THEN)
+11   ^ ^       c+
+13   ^    ^    (*FAIL)
+13   ^   ^     (*FAIL)
+13   ^  ^      (*FAIL)
No match
    
/a(*MARK)b/
Failed: error 166 at offset 7: (*MARK) must have an argument

/(?i:A{1,}\6666666666)/
Failed: error 161 at offset 19: number is too big

/\g6666666666/
Failed: error 161 at offset 11: number is too big

/[\g6666666666]/B
------------------------------------------------------------------
        Bra
        [6g]
        Ket
        End
------------------------------------------------------------------

/(?1)\c[/
Failed: error 115 at offset 3: reference to non-existent subpattern

/.+A/newline=crlf
    \r\nA
No match
    
/\nA/newline=crlf
    \r\nA 
 0: \x0aA

/[\r\n]A/newline=crlf
    \r\nA 
 0: \x0aA

/(\r|\n)A/newline=crlf
    \r\nA 
 0: \x0aA
 1: \x0a

/a(*CR)b/
Failed: error 160 at offset 5: (*VERB) not recognized or malformed

/(*CR)a.b/
    a\nb
 0: a\x0ab
    ** Failers
No match
    a\rb  
No match

/(*CR)a.b/newline=lf
    a\nb
 0: a\x0ab
    ** Failers
No match
    a\rb  
No match

/(*LF)a.b/newline=CRLF
    a\rb
 0: a\x0db
    ** Failers
No match
    a\nb  
No match

/(*CRLF)a.b/
    a\rb
 0: a\x0db
    a\nb  
 0: a\x0ab
    ** Failers
No match
    a\r\nb  
No match

/(*ANYCRLF)a.b/newline=CR
    ** Failers
No match
    a\rb
No match
    a\nb  
No match
    a\r\nb  
No match

/(*ANY)a.b/newline=cr
    ** Failers
No match
    a\rb
No match
    a\nb  
No match
    a\r\nb  
No match
    a\x85b 
No match
    
/(*ANY).*/g
    abc\r\ndef
 0: abc
 0: 
 0: def
 0: 

/(*ANYCRLF).*/g
    abc\r\ndef
 0: abc
 0: 
 0: def
 0: 

/(*CRLF).*/g
    abc\r\ndef
 0: abc
 0: 
 0: def
 0: 

/a\Rb/I,bsr=anycrlf
Capturing subpattern count = 0
\R matches CR, LF, or CRLF
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3
    a\rb
 0: a\x0db
    a\nb
 0: a\x0ab
    a\r\nb
 0: a\x0d\x0ab
    ** Failers
No match
    a\x85b
No match
    a\x0bb     
No match

/a\Rb/I,bsr=unicode
Capturing subpattern count = 0
\R matches any Unicode newline
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3
    a\rb
 0: a\x0db
    a\nb
 0: a\x0ab
    a\r\nb
 0: a\x0d\x0ab
    a\x85b
 0: a\x85b
    a\x0bb     
 0: a\x0bb
    ** Failers 
No match
    a\x85b\=bsr=anycrlf
No match
    a\x0bb\=bsr=anycrlf
No match
    
/a\R?b/I,bsr=anycrlf
Capturing subpattern count = 0
\R matches CR, LF, or CRLF
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
    a\rb
 0: a\x0db
    a\nb
 0: a\x0ab
    a\r\nb
 0: a\x0d\x0ab
    ** Failers
No match
    a\x85b
No match
    a\x0bb     
No match

/a\R?b/I,bsr=unicode
Capturing subpattern count = 0
\R matches any Unicode newline
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
    a\rb
 0: a\x0db
    a\nb
 0: a\x0ab
    a\r\nb
 0: a\x0d\x0ab
    a\x85b
 0: a\x85b
    a\x0bb     
 0: a\x0bb
    ** Failers 
No match
    a\x85b\=bsr=anycrlf
No match
    a\x0bb\=bsr=anycrlf
No match
    
/a\R{2,4}b/I,bsr=anycrlf
Capturing subpattern count = 0
\R matches CR, LF, or CRLF
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 4
    a\r\n\nb
 0: a\x0d\x0a\x0ab
    a\n\r\rb
 0: a\x0a\x0d\x0db
    a\r\n\r\n\r\n\r\nb
 0: a\x0d\x0a\x0d\x0a\x0d\x0a\x0d\x0ab
    ** Failers
No match
    a\x85\x85b
No match
    a\x0b\x0bb     
No match

/a\R{2,4}b/I,bsr=unicode
Capturing subpattern count = 0
\R matches any Unicode newline
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 4
    a\r\rb
 0: a\x0d\x0db
    a\n\n\nb
 0: a\x0a\x0a\x0ab
    a\r\n\n\r\rb
 0: a\x0d\x0a\x0a\x0d\x0db
    a\x85\x85b
 0: a\x85\x85b
    a\x0b\x0bb     
 0: a\x0b\x0bb
    ** Failers 
No match
    a\r\r\r\r\rb 
No match
    a\x85\x85b\=bsr=anycrlf
No match
    a\x0b\x0bb\=bsr=anycrlf
No match
 
/(*BSR_ANYCRLF)a\Rb/I
Capturing subpattern count = 0
\R matches CR, LF, or CRLF
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3
    a\nb
 0: a\x0ab
    a\rb 
 0: a\x0db

/(*BSR_UNICODE)a\Rb/I
Capturing subpattern count = 0
\R matches any Unicode newline
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3
    a\x85b
 0: a\x85b

/(*BSR_ANYCRLF)(*CRLF)a\Rb/I
Capturing subpattern count = 0
\R matches CR, LF, or CRLF
Forced newline is CRLF
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3
    a\nb
 0: a\x0ab
    a\rb 
 0: a\x0db

/(*CRLF)(*BSR_UNICODE)a\Rb/I
Capturing subpattern count = 0
\R matches any Unicode newline
Forced newline is CRLF
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3
    a\x85b
 0: a\x85b

/(*CRLF)(*BSR_ANYCRLF)(*CR)ab/I
Capturing subpattern count = 0
\R matches CR, LF, or CRLF
Forced newline is CR
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/(?<a>)(?&)/
Failed: error 162 at offset 9: subpattern name expected

/(?<abc>)(?&a)/
Failed: error 115 at offset 12: reference to non-existent subpattern

/(?<a>)(?&aaaaaaaaaaaaaaaaaaaaaaa)/
Failed: error 115 at offset 32: reference to non-existent subpattern

/(?+-a)/
Failed: error 163 at offset 3: digit expected after (?+

/(?-+a)/
Failed: error 111 at offset 3: unrecognized character after (? or (?-

/(?(-1))/
Failed: error 115 at offset 6: reference to non-existent subpattern

/(?(+10))/
Failed: error 115 at offset 7: reference to non-existent subpattern

/(?(10))/
Failed: error 115 at offset 6: reference to non-existent subpattern

/(?(+2))()()/

/(?(2))()()/

/\k''/
Failed: error 162 at offset 3: subpattern name expected

/\k<>/
Failed: error 162 at offset 3: subpattern name expected

/\k{}/
Failed: error 162 at offset 3: subpattern name expected

/\k/
Failed: error 169 at offset 2: \k is not followed by a braced, angle-bracketed, or quoted name

/\kabc/
Failed: error 169 at offset 5: \k is not followed by a braced, angle-bracketed, or quoted name

/(?P=)/
Failed: error 162 at offset 4: subpattern name expected

/(?P>)/
Failed: error 162 at offset 4: subpattern name expected

/(?!\w)(?R)/
Failed: error 140 at offset 9: recursion could loop indefinitely

/(?=\w)(?R)/
Failed: error 140 at offset 9: recursion could loop indefinitely

/(?<!\w)(?R)/
Failed: error 140 at offset 10: recursion could loop indefinitely

/(?<=\w)(?R)/
Failed: error 140 at offset 10: recursion could loop indefinitely

/[[:foo:]]/
Failed: error 130 at offset 3: unknown POSIX class name

/[[:1234:]]/
Failed: error 130 at offset 3: unknown POSIX class name

/[[:f\oo:]]/
Failed: error 130 at offset 3: unknown POSIX class name

/[[: :]]/
Failed: error 130 at offset 3: unknown POSIX class name

/[[:...:]]/
Failed: error 130 at offset 3: unknown POSIX class name

/[[:l\ower:]]/
Failed: error 130 at offset 3: unknown POSIX class name

/[[:abc\:]]/
Failed: error 130 at offset 3: unknown POSIX class name

/[abc[:x\]pqr:]]/
Failed: error 130 at offset 6: unknown POSIX class name

/[[:a\dz:]]/
Failed: error 130 at offset 3: unknown POSIX class name

/(^(a|b\g<-1'c))/
Failed: error 157 at offset 15: \g is not followed by a braced, angle-bracketed, or quoted name/number or by a plain number

/^(?+1)(?<a>x|y){0}z/
    xzxx
 0: xz
    yzyy 
 0: yz
    ** Failers
No match
    xxz  
No match

/(\3)(\1)(a)/
    cat
No match

/(\3)(\1)(a)/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    cat
 0: a
 1: 
 2: 
 3: a
    
/TA]/
    The ACTA] comes 
 0: TA]

/TA]/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    The ACTA] comes 
 0: TA]

/(?2)[]a()b](abc)/
Failed: error 115 at offset 3: reference to non-existent subpattern
    abcbabc

/(?2)[^]a()b](abc)/
Failed: error 115 at offset 3: reference to non-existent subpattern
    abcbabc

/(?1)[]a()b](abc)/
    abcbabc
 0: abcbabc
 1: abc
    ** Failers 
No match
    abcXabc
No match

/(?1)[^]a()b](abc)/
    abcXabc
 0: abcXabc
 1: abc
    ** Failers 
No match
    abcbabc
No match

/(?2)[]a()b](abc)(xyz)/
    xyzbabcxyz
 0: xyzbabcxyz
 1: abc
 2: xyz

/(?&N)[]a(?<N>)](?<M>abc)/
Failed: error 115 at offset 4: reference to non-existent subpattern
   abc<abc

/(?&N)[]a(?<N>)](abc)/
Failed: error 115 at offset 4: reference to non-existent subpattern
   abc<abc

/a[]b/
Failed: error 106 at offset 4: missing terminating ] for character class

/a[^]b/
Failed: error 106 at offset 5: missing terminating ] for character class

/a[]b/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    ** Failers
No match
    ab
No match

/a[]+b/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    ** Failers
No match
    ab 
No match

/a[]*+b/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    ** Failers
No match
    ab 
No match

/a[^]b/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    aXb
 0: aXb
    a\nb 
 0: a\x0ab
    ** Failers
No match
    ab  
No match
    
/a[^]+b/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    aXb
 0: aXb
    a\nX\nXb 
 0: a\x0aX\x0aXb
    ** Failers
No match
    ab  
No match

/a(?!)b/B
------------------------------------------------------------------
        Bra
        a
        *FAIL
        b
        Ket
        End
------------------------------------------------------------------

/(?!)?a/B
------------------------------------------------------------------
        Bra
        Brazero
        Assert not
        Ket
        a
        Ket
        End
------------------------------------------------------------------
    ab
 0: a

/a(*FAIL)+b/
Failed: error 109 at offset 8: nothing to repeat

/(abc|pqr|123){0}[xyz]/I
Capturing subpattern count = 1
Starting code units: x y z 
Subject length lower bound = 1

/(?(?=.*b)b|^)/I,auto_callout
Capturing subpattern count = 0
May match empty string
Options: auto_callout
Subject length lower bound = 0
   adc
--->adc
 +0 ^       (?(?=.*b)b|^)
 +2 ^       (?=.*b)
 +5 ^       .*
 +7 ^  ^    b
 +7 ^ ^     b
 +7 ^^      b
 +7 ^       b
+11 ^       ^
+12 ^       )
+13 ^       
 0: 
   abc 
--->abc
 +0 ^       (?(?=.*b)b|^)
 +2 ^       (?=.*b)
 +5 ^       .*
 +7 ^  ^    b
 +7 ^ ^     b
 +7 ^^      b
 +8 ^ ^     )
 +9 ^       b
 +0  ^      (?(?=.*b)b|^)
 +2  ^      (?=.*b)
 +5  ^      .*
 +7  ^ ^    b
 +7  ^^     b
 +7  ^      b
 +8  ^^     )
 +9  ^      b
+10  ^^     |
+13  ^^     
 0: b
   
/(?(?=b).*b|^d)/I
Capturing subpattern count = 0
Subject length lower bound = 1

/(?(?=.*b).*b|^d)/I
Capturing subpattern count = 0
First code unit at start or follows newline
Subject length lower bound = 1

/xyz/auto_callout
  xyz 
--->xyz
 +0 ^       x
 +1 ^^      y
 +2 ^ ^     z
 +3 ^  ^    
 0: xyz
  abcxyz 
--->abcxyz
 +0    ^       x
 +1    ^^      y
 +2    ^ ^     z
 +3    ^  ^    
 0: xyz
  abcxyz\=no_start_optimize
--->abcxyz
 +0 ^          x
 +0  ^         x
 +0   ^        x
 +0    ^       x
 +1    ^^      y
 +2    ^ ^     z
 +3    ^  ^    
 0: xyz
  ** Failers 
No match
  abc
No match
  abc\=no_start_optimize
--->abc
 +0 ^       x
 +0  ^      x
 +0   ^     x
 +0    ^    x
No match
  abcxypqr  
No match
  abcxypqr\=no_start_optimize
--->abcxypqr
 +0 ^            x
 +0  ^           x
 +0   ^          x
 +0    ^         x
 +1    ^^        y
 +2    ^ ^       z
 +0     ^        x
 +0      ^       x
 +0       ^      x
 +0        ^     x
 +0         ^    x
No match
  
/(*NO_START_OPT)xyz/auto_callout
  abcxyz
--->abcxyz
+15 ^          x
+15  ^         x
+15   ^        x
+15    ^       x
+16    ^^      y
+17    ^ ^     z
+18    ^  ^    
 0: xyz
  
/(*NO_AUTO_POSSESS)a+b/B
------------------------------------------------------------------
        Bra
        a++
        b
        Ket
        End
------------------------------------------------------------------

/xyz/auto_callout,no_start_optimize
  abcxyz 
--->abcxyz
 +0 ^          x
 +0  ^         x
 +0   ^        x
 +0    ^       x
 +1    ^^      y
 +2    ^ ^     z
 +3    ^  ^    
 0: xyz

/^"((?(?=[a])[^"])|b)*"$/auto_callout
    "ab"
--->"ab"
 +0 ^        ^
 +1 ^        "
 +2 ^^       ((?(?=[a])[^"])|b)*
 +3 ^^       (?(?=[a])[^"])
 +5 ^^       (?=[a])
 +8 ^^       [a]
+11 ^ ^      )
+12 ^^       [^"]
+16 ^ ^      )
+17 ^ ^      |
 +3 ^ ^      (?(?=[a])[^"])
 +5 ^ ^      (?=[a])
 +8 ^ ^      [a]
+17 ^ ^      |
+21 ^ ^      "
+18 ^ ^      b
+19 ^  ^     )
 +3 ^  ^     (?(?=[a])[^"])
 +5 ^  ^     (?=[a])
 +8 ^  ^     [a]
+17 ^  ^     |
+21 ^  ^     "
+22 ^   ^    $
+23 ^   ^    
 0: "ab"
 1: 

/^"((?(?=[a])[^"])|b)*"$/
    "ab"
 0: "ab"
 1: 

/^X(?5)(a)(?|(b)|(q))(c)(d)Y/
Failed: error 115 at offset 5: reference to non-existent subpattern
    XYabcdY

/^X(?&N)(a)(?|(b)|(q))(c)(d)(?<N>Y)/
    XYabcdY
 0: XYabcdY
 1: a
 2: b
 3: c
 4: d
 5: Y
 
/Xa{2,4}b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/Xa{2,4}?b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/Xa{2,4}+b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/X\d{2,4}b/
    X\=ps
Partial match: X
    X3\=ps
Partial match: X3
    X33\=ps
Partial match: X33
    X333\=ps
Partial match: X333
    X3333\=ps
Partial match: X3333
    
/X\d{2,4}?b/
    X\=ps
Partial match: X
    X3\=ps
Partial match: X3
    X33\=ps
Partial match: X33
    X333\=ps
Partial match: X333
    X3333\=ps
Partial match: X3333
    
/X\d{2,4}+b/
    X\=ps
Partial match: X
    X3\=ps
Partial match: X3
    X33\=ps
Partial match: X33
    X333\=ps
Partial match: X333
    X3333\=ps
Partial match: X3333
    
/X\D{2,4}b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/X\D{2,4}?b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/X\D{2,4}+b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/X[abc]{2,4}b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/X[abc]{2,4}?b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/X[abc]{2,4}+b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/X[^a]{2,4}b/
    X\=ps
Partial match: X
    Xz\=ps
Partial match: Xz
    Xzz\=ps
Partial match: Xzz
    Xzzz\=ps
Partial match: Xzzz
    Xzzzz\=ps
Partial match: Xzzzz
    
/X[^a]{2,4}?b/
    X\=ps
Partial match: X
    Xz\=ps
Partial match: Xz
    Xzz\=ps
Partial match: Xzz
    Xzzz\=ps
Partial match: Xzzz
    Xzzzz\=ps
Partial match: Xzzzz
    
/X[^a]{2,4}+b/
    X\=ps
Partial match: X
    Xz\=ps
Partial match: Xz
    Xzz\=ps
Partial match: Xzz
    Xzzz\=ps
Partial match: Xzzz
    Xzzzz\=ps
Partial match: Xzzzz
    
/(Y)X\1{2,4}b/
    YX\=ps
Partial match: YX
    YXY\=ps
Partial match: YXY
    YXYY\=ps
Partial match: YXYY
    YXYYY\=ps
Partial match: YXYYY
    YXYYYY\=ps
Partial match: YXYYYY
    
/(Y)X\1{2,4}?b/
    YX\=ps
Partial match: YX
    YXY\=ps
Partial match: YXY
    YXYY\=ps
Partial match: YXYY
    YXYYY\=ps
Partial match: YXYYY
    YXYYYY\=ps
Partial match: YXYYYY
    
/(Y)X\1{2,4}+b/
    YX\=ps
Partial match: YX
    YXY\=ps
Partial match: YXY
    YXYY\=ps
Partial match: YXYY
    YXYYY\=ps
Partial match: YXYYY
    YXYYYY\=ps
Partial match: YXYYYY
    
/\++\KZ|\d+X|9+Y/
    ++++123999\=ps
Partial match: 123999
    ++++123999Y\=ps
 0: 999Y
    ++++Z1234\=ps
 0: Z

/Z(*F)/
    Z\=ps
No match
    ZA\=ps
No match
    
/Z(?!)/
    Z\=ps
No match
    ZA\=ps
No match

/dog(sbody)?/
    dogs\=ps
 0: dog
    dogs\=ph
Partial match: dogs
    
/dog(sbody)??/
    dogs\=ps
 0: dog
    dogs\=ph
 0: dog

/dog|dogsbody/
    dogs\=ps
 0: dog
    dogs\=ph
 0: dog
 
/dogsbody|dog/
    dogs\=ps
 0: dog
    dogs\=ph
Partial match: dogs

/\bthe cat\b/
    the cat\=ps
 0: the cat
    the cat\=ph
Partial match: the cat

/abc/
   abc\=ps
 0: abc
   abc\=ph
 0: abc
   
/abc\K123/
    xyzabc123pqr
 0: 123
    xyzabc12\=ps
Partial match: abc12
    xyzabc12\=ph
Partial match: abc12
    
/(?<=abc)123/
    xyzabc123pqr 
 0: 123
    xyzabc12\=ps
Partial match at offset 6: abc12
    xyzabc12\=ph
Partial match at offset 6: abc12

/\babc\b/
    +++abc+++
 0: abc
    +++ab\=ps
Partial match at offset 3: +ab
    +++ab\=ph
Partial match at offset 3: +ab

/(?&word)(?&element)(?(DEFINE)(?<element><[^m][^>]>[^<])(?<word>\w*+))/B
------------------------------------------------------------------
        Bra
        Recurse
        Recurse
        Cond
        Cond false
        CBra 1
        <
        [^m]
        [^>]
        >
        [^<]
        Ket
        CBra 2
        \w*+
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------

/(?&word)(?&element)(?(DEFINE)(?<element><[^\d][^>]>[^<])(?<word>\w*+))/B
------------------------------------------------------------------
        Bra
        Recurse
        Recurse
        Cond
        Cond false
        CBra 1
        <
        [\x00-/:-\xff] (neg)
        [^>]
        >
        [^<]
        Ket
        CBra 2
        \w*+
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------

/(ab)(x(y)z(cd(*ACCEPT)))pq/B
------------------------------------------------------------------
        Bra
        CBra 1
        ab
        Ket
        CBra 2
        x
        CBra 3
        y
        Ket
        z
        CBra 4
        cd
        Close 4
        Close 2
        *ACCEPT
        Ket
        Ket
        pq
        Ket
        End
------------------------------------------------------------------

/abc\K/aftertext
    abcdef
 0: 
 0+ def
    abcdef\=notempty_atstart
 0: 
 0+ def
    xyzabcdef\=notempty_atstart
 0: 
 0+ def
    ** Failers
No match
    abcdef\=notempty
No match
    xyzabcdef\=notempty
No match
    
/^(?:(?=abc)|abc\K)/aftertext
    abcdef
 0: 
 0+ abcdef
    abcdef\=notempty_atstart
 0: 
 0+ def
    ** Failers 
No match
    abcdef\=notempty
No match

/a?b?/aftertext
    xyz
 0: 
 0+ xyz
    xyzabc
 0: 
 0+ xyzabc
    xyzabc\=notempty
 0: ab
 0+ c
    xyzabc\=notempty_atstart
 0: 
 0+ yzabc
    xyz\=notempty_atstart
 0: 
 0+ yz
    ** Failers 
 0: 
 0+ ** Failers
    xyz\=notempty
No match

/^a?b?/aftertext
    xyz
 0: 
 0+ xyz
    xyzabc
 0: 
 0+ xyzabc
    ** Failers 
 0: 
 0+ ** Failers
    xyzabc\=notempty
No match
    xyzabc\=notempty_atstart
No match
    xyz\=notempty_atstart
No match
    xyz\=notempty
No match
    
/^(?<name>a|b\g<name>c)/
    aaaa
 0: a
 1: a
    bacxxx
 0: bac
 1: bac
    bbaccxxx 
 0: bbacc
 1: bbacc
    bbbacccxx
 0: bbbaccc
 1: bbbaccc

/^(?<name>a|b\g'name'c)/
    aaaa
 0: a
 1: a
    bacxxx
 0: bac
 1: bac
    bbaccxxx 
 0: bbacc
 1: bbacc
    bbbacccxx
 0: bbbaccc
 1: bbbaccc

/^(a|b\g<1>c)/
    aaaa
 0: a
 1: a
    bacxxx
 0: bac
 1: bac
    bbaccxxx 
 0: bbacc
 1: bbacc
    bbbacccxx
 0: bbbaccc
 1: bbbaccc

/^(a|b\g'1'c)/
    aaaa
 0: a
 1: a
    bacxxx
 0: bac
 1: bac
    bbaccxxx 
 0: bbacc
 1: bbacc
    bbbacccxx
 0: bbbaccc
 1: bbbaccc

/^(a|b\g'-1'c)/
    aaaa
 0: a
 1: a
    bacxxx
 0: bac
 1: bac
    bbaccxxx 
 0: bbacc
 1: bbacc
    bbbacccxx
 0: bbbaccc
 1: bbbaccc

/(^(a|b\g<-1>c))/
    aaaa
 0: a
 1: a
 2: a
    bacxxx
 0: bac
 1: bac
 2: bac
    bbaccxxx 
 0: bbacc
 1: bbacc
 2: bbacc
    bbbacccxx
 0: bbbaccc
 1: bbbaccc
 2: bbbaccc

/(?-i:\g<name>)(?i:(?<name>a))/
    XaaX
 0: aa
 1: a
    XAAX 
 0: AA
 1: A

/(?i:\g<name>)(?-i:(?<name>a))/
    XaaX
 0: aa
 1: a
    ** Failers 
No match
    XAAX 
No match

/(?-i:\g<+1>)(?i:(a))/
    XaaX
 0: aa
 1: a
    XAAX 
 0: AA
 1: A

/(?=(?<regex>(?#simplesyntax)\$(?<name>[a-zA-Z_\x{7f}-\x{ff}][a-zA-Z0-9_\x{7f}-\x{ff}]*)(?:\[(?<index>[a-zA-Z0-9_\x{7f}-\x{ff}]+|\$\g<name>)\]|->\g<name>(\(.*?\))?)?|(?#simple syntax withbraces)\$\{(?:\g<name>(?<indices>\[(?:\g<index>|'(?:\\.|[^'\\])*'|"(?:\g<regex>|\\.|[^"\\])*")\])?|\g<complex>|\$\{\g<complex>\})\}|(?#complexsyntax)\{(?<complex>\$(?<segment>\g<name>(\g<indices>*|\(.*?\))?)(?:->\g<segment>)*|\$\g<complex>|\$\{\g<complex>\})\}))\{/

/(?<n>a|b|c)\g<n>*/
   abc
 0: abc
 1: a
   accccbbb 
 0: accccbbb
 1: a

/^X(?7)(a)(?|(b)|(q)(r)(s))(c)(d)(Y)/
    XYabcdY
 0: XYabcdY
 1: a
 2: b
 3: <unset>
 4: <unset>
 5: c
 6: d
 7: Y

/(?<=b(?1)|zzz)(a)/
    xbaax
 0: a
 1: a
    xzzzax 
 0: a
 1: a

/(a)(?<=b\1)/
Failed: error 125 at offset 10: lookbehind assertion is not fixed length

/(a)(?<=b+(?1))/
Failed: error 125 at offset 13: lookbehind assertion is not fixed length

/(a+)(?<=b(?1))/
Failed: error 125 at offset 14: lookbehind assertion is not fixed length

/(a(?<=b(?1)))/
Failed: error 125 at offset 13: lookbehind assertion is not fixed length

/(?<=b(?1))xyz/
Failed: error 115 at offset 8: reference to non-existent subpattern

/(?<=b(?1))xyz(b+)pqrstuvew/
Failed: error 125 at offset 26: lookbehind assertion is not fixed length

/(a|bc)\1/I
Capturing subpattern count = 1
Max back reference = 1
Starting code units: a b 
Subject length lower bound = 2

/(a|bc)\1{2,3}/I
Capturing subpattern count = 1
Max back reference = 1
Starting code units: a b 
Subject length lower bound = 3

/(a|bc)(?1)/I
Capturing subpattern count = 1
Starting code units: a b 
Subject length lower bound = 2

/(a|b\1)(a|b\1)/I
Capturing subpattern count = 2
Max back reference = 1
Starting code units: a b 
Subject length lower bound = 2

/(a|b\1){2}/I
Capturing subpattern count = 1
Max back reference = 1
Starting code units: a b 
Subject length lower bound = 2

/(a|bbbb\1)(a|bbbb\1)/I
Capturing subpattern count = 2
Max back reference = 1
Starting code units: a b 
Subject length lower bound = 2

/(a|bbbb\1){2}/I
Capturing subpattern count = 1
Max back reference = 1
Starting code units: a b 
Subject length lower bound = 2

/^From +([^ ]+) +[a-zA-Z][a-zA-Z][a-zA-Z] +[a-zA-Z][a-zA-Z][a-zA-Z] +[0-9]?[0-9] +[0-9][0-9]:[0-9][0-9]/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Last code unit = ':'
Subject length lower bound = 22

/<tr([\w\W\s\d][^<>]{0,})><TD([\w\W\s\d][^<>]{0,})>([\d]{0,}\.)(.*)((<BR>([\w\W\s\d][^<>]{0,})|[\s]{0,}))<\/a><\/TD><TD([\w\W\s\d][^<>]{0,})>([\w\W\s\d][^<>]{0,})<\/TD><TD([\w\W\s\d][^<>]{0,})>([\w\W\s\d][^<>]{0,})<\/TD><\/TR>/Iis
Capturing subpattern count = 11
Options: caseless dotall
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 47

"(?>.*/)foo"I
Capturing subpattern count = 0
Last code unit = 'o'
Subject length lower bound = 4

/(?(?=[^a-z]+[a-z])  \d{2}-[a-z]{3}-\d{2}  |  \d{2}-\d{2}-\d{2} ) /Ix
Capturing subpattern count = 0
Options: extended
Last code unit = '-'
Subject length lower bound = 8

/(?:(?:(?:(?:(?:(?:(?:(?:(?:(a|b|c))))))))))/Ii
Capturing subpattern count = 1
Options: caseless
Starting code units: A B C a b c 
Subject length lower bound = 1

/(?:c|d)(?:)(?:aaaaaaaa(?:)(?:bbbbbbbb)(?:bbbbbbbb(?:))(?:bbbbbbbb(?:)(?:bbbbbbbb)))/I
Capturing subpattern count = 0
Starting code units: c d 
Last code unit = 'b'
Subject length lower bound = 41

/<a[\s]+href[\s]*=[\s]*          # find <a href=
 ([\"\'])?                       # find single or double quote
 (?(1) (.*?)\1 | ([^\s]+))       # if quote found, match up to next matching
                                 # quote, otherwise match up to next space
/Iisx
Capturing subpattern count = 3
Max back reference = 1
Options: caseless extended dotall
First code unit = '<'
Last code unit = '='
Subject length lower bound = 9

/^(?!:)                       # colon disallowed at start
  (?:                         # start of item
    (?: [0-9a-f]{1,4} |       # 1-4 hex digits or
    (?(1)0 | () ) )           # if null previously matched, fail; else null
    :                         # followed by colon
  ){1,7}                      # end item; 1-7 of them required               
  [0-9a-f]{1,4} $             # final hex number at end of string
  (?(1)|.)                    # check that there was an empty component
  /Iix
Capturing subpattern count = 1
Compile options: caseless extended
Overall options: anchored caseless extended
Last code unit = ':'
Subject length lower bound = 2

/(?|(?<a>A)|(?<a>B))/I
Capturing subpattern count = 1
Named capturing subpatterns:
  a   1
Starting code units: A B 
Subject length lower bound = 1
    AB\=copy=a
 0: A
 1: A
  C A (1) a
    BA\=copy=a
 0: B
 1: B
  C B (1) a

/(?|(?<a>A)|(?<b>B))/
Failed: error 165 at offset 15: different names for subpatterns of the same number are not allowed

/(?:a(?<quote> (?<apostrophe>')|(?<realquote>")) |
    b(?<quote> (?<apostrophe>')|(?<realquote>")) ) 
    (?('quote')[a-z]+|[0-9]+)/Ix,dupnames
Capturing subpattern count = 6
Named capturing subpatterns:
  apostrophe   2
  apostrophe   5
  quote        1
  quote        4
  realquote    3
  realquote    6
Options: extended dupnames
Starting code units: a b 
Subject length lower bound = 3
    a"aaaaa
 0: a"aaaaa
 1: "
 2: <unset>
 3: "
    b"aaaaa 
 0: b"aaaaa
 1: <unset>
 2: <unset>
 3: <unset>
 4: "
 5: <unset>
 6: "
    ** Failers 
No match
    b"11111
No match
    a"11111 
No match
    
/^(?|(a)(b)(c)(?<D>d)|(?<D>e)) (?('D')X|Y)/IBx,dupnames
------------------------------------------------------------------
        Bra
        ^
        Bra
        CBra 1
        a
        Ket
        CBra 2
        b
        Ket
        CBra 3
        c
        Ket
        CBra 4
        d
        Ket
        Alt
        CBra 1
        e
        Ket
        Ket
        Cond
        Cond ref <D>2
        X
        Alt
        Y
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 4
Named capturing subpatterns:
  D   4
  D   1
Compile options: extended dupnames
Overall options: anchored extended dupnames
Subject length lower bound = 2
    abcdX
 0: abcdX
 1: a
 2: b
 3: c
 4: d
    eX
 0: eX
 1: e
    ** Failers
No match
    abcdY
No match
    ey     
No match
    
/(?<A>a) (b)(c)  (?<A>d  (?(R&A)$ | (?4)) )/IBx,dupnames
------------------------------------------------------------------
        Bra
        CBra 1
        a
        Ket
        CBra 2
        b
        Ket
        CBra 3
        c
        Ket
        CBra 4
        d
        Cond
        Cond recurse <A>2
        $
        Alt
        Recurse
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 4
Named capturing subpatterns:
  A   1
  A   4
Options: extended dupnames
First code unit = 'a'
Last code unit = 'd'
Subject length lower bound = 4
    abcdd
 0: abcdd
 1: a
 2: b
 3: c
 4: dd
    ** Failers
No match
    abcdde  
No match

/abcd*/
    xxxxabcd\=ps
 0: abcd
    xxxxabcd\=ph
Partial match: abcd

/abcd*/i
    xxxxabcd\=ps
 0: abcd
    xxxxabcd\=ph
Partial match: abcd
    XXXXABCD\=ps
 0: ABCD
    XXXXABCD\=ph
Partial match: ABCD

/abc\d*/
    xxxxabc1\=ps
 0: abc1
    xxxxabc1\=ph
Partial match: abc1

/(a)bc\1*/
    xxxxabca\=ps
 0: abca
 1: a
    xxxxabca\=ph
Partial match: abca

/abc[de]*/
    xxxxabcde\=ps
 0: abcde
    xxxxabcde\=ph
Partial match: abcde

# This is not in the Perl-compatible test because Perl seems currently to be
# broken and not behaving as specified in that it *does* bumpalong after
# hitting (*COMMIT). 

/(?1)(A(*COMMIT)|B)D/
    ABD
 0: ABD
 1: B
    XABD
 0: ABD
 1: B
    BAD
 0: BAD
 1: A
    ABXABD  
 0: ABD
 1: B
    ** Failers 
No match
    ABX 
No match
    BAXBAD  
No match

/(\3)(\1)(a)/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    cat
 0: a
 1: 
 2: 
 3: a

/(\3)(\1)(a)/I,alt_bsux,allow_empty_class,match_unset_backref,dupnames
Capturing subpattern count = 3
Max back reference = 3
Options: dupnames alt_bsux allow_empty_class match_unset_backref
Last code unit = 'a'
Subject length lower bound = 1
    cat
 0: a
 1: 
 2: 
 3: a

/(\3)(\1)(a)/I
Capturing subpattern count = 3
Max back reference = 3
Last code unit = 'a'
Subject length lower bound = 3
    cat
No match

/i(?(DEFINE)(?<s>a))/I
Capturing subpattern count = 1
Named capturing subpatterns:
  s   1
First code unit = 'i'
Subject length lower bound = 1
    i
 0: i
    
/()i(?(1)a)/I
Capturing subpattern count = 1
First code unit = 'i'
Subject length lower bound = 1
    ia
 0: ia
 1: 

/(?i)a(?-i)b|c/B
------------------------------------------------------------------
        Bra
     /i a
        b
        Alt
        c
        Ket
        End
------------------------------------------------------------------
    XabX
 0: ab
    XAbX
 0: Ab
    CcC 
 0: c
    ** Failers
No match
    XABX   
No match

/(?i)a(?s)b|c/B
------------------------------------------------------------------
        Bra
     /i ab
        Alt
     /i c
        Ket
        End
------------------------------------------------------------------

/(?i)a(?s-i)b|c/B
------------------------------------------------------------------
        Bra
     /i a
        b
        Alt
        c
        Ket
        End
------------------------------------------------------------------

/^(ab(c\1)d|x){2}$/B
------------------------------------------------------------------
        Bra
        ^
        Once
        CBra 1
        ab
        CBra 2
        c
        \1
        Ket
        d
        Alt
        x
        Ket
        Ket
        Once
        CBra 1
        ab
        CBra 2
        c
        \1
        Ket
        d
        Alt
        x
        Ket
        Ket
        $
        Ket
        End
------------------------------------------------------------------
    xabcxd
 0: xabcxd
 1: abcxd
 2: cx
    
/^(?&t)*+(?(DEFINE)(?<t>.))$/B
------------------------------------------------------------------
        Bra
        ^
        Braposzero
        SBraPos
        Recurse
        KetRpos
        Cond
        Cond false
        CBra 1
        Any
        Ket
        Ket
        $
        Ket
        End
------------------------------------------------------------------

/^(?&t)*(?(DEFINE)(?<t>.))$/B
------------------------------------------------------------------
        Bra
        ^
        Brazero
        Once
        Recurse
        KetRmax
        Cond
        Cond false
        CBra 1
        Any
        Ket
        Ket
        $
        Ket
        End
------------------------------------------------------------------

/ -- This one is here because Perl gives the match as "b" rather than "ab". I
     believe this to be a Perl bug. --/
      
/(?>a\Kb)z|(ab)/
    ab 
 0: ab
 1: ab

/(?P<L1>(?P<L2>0|)|(?P>L2)(?P>L1))/
Failed: error 140 at offset 31: recursion could loop indefinitely

/abc(*MARK:)pqr/
Failed: error 166 at offset 10: (*MARK) must have an argument

/abc(*:)pqr/
Failed: error 166 at offset 6: (*MARK) must have an argument

/abc(*FAIL:123)xyz/
Failed: error 159 at offset 13: an argument is not allowed for (*ACCEPT), (*FAIL), or (*COMMIT)

# This should, and does, fail. In Perl, it does not, which I think is a 
# bug because replacing the B in the pattern by (B|D) does make it fail.

/A(*COMMIT)B/aftertext,mark
    ACABX
No match

# These should be different, but in Perl they are not, which I think
# is a bug in Perl.

/A(*THEN)B|A(*THEN)C/mark
    AC
 0: AC

/A(*PRUNE)B|A(*PRUNE)C/mark
    AC
No match
    
# Mark names can be duplicated. Perl doesn't give a mark for this one,
# though PCRE2 does.

/^A(*:A)B|^X(*:A)Y/mark
    ** Failers
No match
    XAQQ
No match, mark = A
    
# COMMIT at the start of a pattern should be the same as an anchor. Perl 
# optimizations defeat this. So does the PCRE2 optimization unless we disable
# it.

/(*COMMIT)ABC/
    ABCDEFG
 0: ABC
    ** Failers
No match
    DEFGABC\=no_start_optimize
No match
    
/^(ab (c+(*THEN)cd) | xyz)/x
    abcccd  
No match

/^(ab (c+(*PRUNE)cd) | xyz)/x
    abcccd  
No match

/^(ab (c+(*FAIL)cd) | xyz)/x
    abcccd  
No match
    
# Perl gets some of these wrong

/(?>.(*ACCEPT))*?5/
    abcde
 0: a

/(.(*ACCEPT))*?5/
    abcde
 0: a
 1: a

/(.(*ACCEPT))5/
    abcde
 0: a
 1: a

/(.(*ACCEPT))*5/
    abcde
 0: a
 1: a

/A\NB./B
------------------------------------------------------------------
        Bra
        A
        Any
        B
        Any
        Ket
        End
------------------------------------------------------------------
    ACBD
 0: ACBD
    *** Failers
No match
    A\nB
No match
    ACB\n   
No match

/A\NB./Bs
------------------------------------------------------------------
        Bra
        A
        Any
        B
        AllAny
        Ket
        End
------------------------------------------------------------------
    ACBD
 0: ACBD
    ACB\n 
 0: ACB\x0a
    *** Failers
No match
    A\nB  
No match
  
/A\NB/newline=crlf
    A\nB
 0: A\x0aB
    A\rB
 0: A\x0dB
    ** Failers
No match
    A\r\nB    
No match

/\R+b/B
------------------------------------------------------------------
        Bra
        \R++
        b
        Ket
        End
------------------------------------------------------------------

/\R+\n/B
------------------------------------------------------------------
        Bra
        \R+
        \x0a
        Ket
        End
------------------------------------------------------------------

/\R+\d/B
------------------------------------------------------------------
        Bra
        \R++
        \d
        Ket
        End
------------------------------------------------------------------

/\d*\R/B
------------------------------------------------------------------
        Bra
        \d*+
        \R
        Ket
        End
------------------------------------------------------------------

/\s*\R/B
------------------------------------------------------------------
        Bra
        \s*
        \R
        Ket
        End
------------------------------------------------------------------
    \x20\x0a
 0:  \x0a
    \x20\x0d
 0:  \x0d
    \x20\x0d\x0a
 0:  \x0d\x0a

/\S*\R/B
------------------------------------------------------------------
        Bra
        \S*+
        \R
        Ket
        End
------------------------------------------------------------------
    a\x0a
 0: a\x0a

/X\h*\R/B
------------------------------------------------------------------
        Bra
        X
        \h*+
        \R
        Ket
        End
------------------------------------------------------------------
    X\x20\x0a
 0: X \x0a

/X\H*\R/B
------------------------------------------------------------------
        Bra
        X
        \H*
        \R
        Ket
        End
------------------------------------------------------------------
    X\x0d\x0a
 0: X\x0d\x0a

/X\H+\R/B
------------------------------------------------------------------
        Bra
        X
        \H+
        \R
        Ket
        End
------------------------------------------------------------------
    X\x0d\x0a
 0: X\x0d\x0a

/X\H++\R/B
------------------------------------------------------------------
        Bra
        X
        \H++
        \R
        Ket
        End
------------------------------------------------------------------
    X\x0d\x0a
No match

/(?<=abc)def/
    abc\=ph
Partial match at offset 3: abc

/abc$/
    abc
 0: abc
    abc\=ps
 0: abc
    abc\=ph
Partial match: abc

/abc$/m
    abc
 0: abc
    abc\n
 0: abc
    abc\=ph
Partial match: abc
    abc\n\=ph
 0: abc
    abc\=ps
 0: abc
    abc\n\=ps
 0: abc

/abc\z/
    abc
 0: abc
    abc\=ps
 0: abc
    abc\=ph
Partial match: abc

/abc\Z/
    abc
 0: abc
    abc\=ps
 0: abc
    abc\=ph
Partial match: abc

/abc\b/
    abc
 0: abc
    abc\=ps
 0: abc
    abc\=ph
Partial match: abc

/abc\B/
    abc
No match
    abc\=ps
Partial match: abc
    abc\=ph
Partial match: abc

/.+/
    abc\=offset=0
 0: abc
    abc\=offset=1
 0: bc
    abc\=offset=2
 0: c
    abc\=offset=3
No match
    abc\=offset=4
Failed: error -33: bad offset value
    abc\=offset=-4 
** Invalid value in 'offset=-4'

/^\cģ/
Failed: error 168 at offset 3: \c must be followed by a printable ASCII character

/(?P<abn>(?P=abn)xxx)/B
------------------------------------------------------------------
        Bra
        Once
        CBra 1
        \1
        xxx
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------

/(a\1z)/B
------------------------------------------------------------------
        Bra
        Once
        CBra 1
        a
        \1
        z
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------

/(?P<abn>(?P=abn)(?<badstufxxx)/B
Failed: error 142 at offset 29: syntax error in subpattern name (missing terminator)

/(?P<abn>(?P=axn)xxx)/B
Failed: error 115 at offset 15: reference to non-existent subpattern

/(?P<abn>(?P=axn)xxx)(?<axn>yy)/B
------------------------------------------------------------------
        Bra
        CBra 1
        \2
        xxx
        Ket
        CBra 2
        yy
        Ket
        Ket
        End
------------------------------------------------------------------

# These tests are here because Perl gets the first one wrong. 

/(\R*)(.)/s
    \r\n
 0: \x0d
 1: 
 2: \x0d
    \r\r\n\n\r 
 0: \x0d\x0d\x0a\x0a\x0d
 1: \x0d\x0d\x0a\x0a
 2: \x0d
    \r\r\n\n\r\n 
 0: \x0d\x0d\x0a\x0a\x0d
 1: \x0d\x0d\x0a\x0a
 2: \x0d

/(\R)*(.)/s
    \r\n
 0: \x0d
 1: <unset>
 2: \x0d
    \r\r\n\n\r 
 0: \x0d\x0d\x0a\x0a\x0d
 1: \x0a
 2: \x0d
    \r\r\n\n\r\n 
 0: \x0d\x0d\x0a\x0a\x0d
 1: \x0a
 2: \x0d

/((?>\r\n|\n|\x0b|\f|\r|\x85)*)(.)/s
    \r\n
 0: \x0d
 1: 
 2: \x0d
    \r\r\n\n\r 
 0: \x0d\x0d\x0a\x0a\x0d
 1: \x0d\x0d\x0a\x0a
 2: \x0d
    \r\r\n\n\r\n 
 0: \x0d\x0d\x0a\x0a\x0d
 1: \x0d\x0d\x0a\x0a
 2: \x0d

# ------------- 

/^abc$/B
------------------------------------------------------------------
        Bra
        ^
        abc
        $
        Ket
        End
------------------------------------------------------------------

/^abc$/Bm
------------------------------------------------------------------
        Bra
     /m ^
        abc
     /m $
        Ket
        End
------------------------------------------------------------------

/^(a)*+(\w)/
    aaaaX
 0: aaaaX
 1: a
 2: X
    ** Failers 
No match
    aaaa
No match

/^(?:a)*+(\w)/
    aaaaX
 0: aaaaX
 1: X
    ** Failers 
No match
    aaaa
No match

/(a)++1234/IB
------------------------------------------------------------------
        Bra
        CBraPos 1
        a
        KetRpos
        1234
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = '4'
Subject length lower bound = 5

/([abc])++1234/I
Capturing subpattern count = 1
Starting code units: a b c 
Last code unit = '4'
Subject length lower bound = 5

/(?<=(abc)+)X/
Failed: error 125 at offset 10: lookbehind assertion is not fixed length

/(^ab)/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2

/(^ab)++/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2

/(^ab|^)+/I
Capturing subpattern count = 1
May match empty string
Compile options: <none>
Overall options: anchored
Subject length lower bound = 0

/(^ab|^)++/I
Capturing subpattern count = 1
May match empty string
Compile options: <none>
Overall options: anchored
Subject length lower bound = 0

/(?:^ab)/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2

/(?:^ab)++/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2

/(?:^ab|^)+/I
Capturing subpattern count = 0
May match empty string
Compile options: <none>
Overall options: anchored
Subject length lower bound = 0

/(?:^ab|^)++/I
Capturing subpattern count = 0
May match empty string
Compile options: <none>
Overall options: anchored
Subject length lower bound = 0

/(.*ab)/I
Capturing subpattern count = 1
First code unit at start or follows newline
Last code unit = 'b'
Subject length lower bound = 2

/(.*ab)++/I
Capturing subpattern count = 1
First code unit at start or follows newline
Last code unit = 'b'
Subject length lower bound = 2

/(.*ab|.*)+/I
Capturing subpattern count = 1
May match empty string
First code unit at start or follows newline
Subject length lower bound = 0

/(.*ab|.*)++/I
Capturing subpattern count = 1
May match empty string
First code unit at start or follows newline
Subject length lower bound = 0

/(?:.*ab)/I
Capturing subpattern count = 0
First code unit at start or follows newline
Last code unit = 'b'
Subject length lower bound = 2

/(?:.*ab)++/I
Capturing subpattern count = 0
First code unit at start or follows newline
Last code unit = 'b'
Subject length lower bound = 2

/(?:.*ab|.*)+/I
Capturing subpattern count = 0
May match empty string
First code unit at start or follows newline
Subject length lower bound = 0

/(?:.*ab|.*)++/I
Capturing subpattern count = 0
May match empty string
First code unit at start or follows newline
Subject length lower bound = 0

/(?=a)[bcd]/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1

/((?=a))[bcd]/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 1

/((?=a))+[bcd]/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 1

/((?=a))++[bcd]/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 1

/(?=a+)[bcd]/Ii
Capturing subpattern count = 0
Options: caseless
First code unit = 'a' (caseless)
Subject length lower bound = 1

/(?=a+?)[bcd]/Ii
Capturing subpattern count = 0
Options: caseless
First code unit = 'a' (caseless)
Subject length lower bound = 1

/(?=a++)[bcd]/Ii
Capturing subpattern count = 0
Options: caseless
First code unit = 'a' (caseless)
Subject length lower bound = 1

/(?=a{3})[bcd]/Ii
Capturing subpattern count = 0
Options: caseless
First code unit = 'a' (caseless)
Last code unit = 'a' (caseless)
Subject length lower bound = 1

/(abc)\1+/

# Perl doesn't get these right IMO (the 3rd is PCRE2-specific) 

/(?1)(?:(b(*ACCEPT))){0}/
    b
 0: b

/(?1)(?:(b(*ACCEPT))){0}c/
    bc
 0: bc
    ** Failers 
No match
    b 
No match

/(?1)(?:((*ACCEPT))){0}c/
    c
 0: c
    c\=notempty
 0: c

/^.*?(?(?=a)a|b(*THEN)c)/
    ba
No match

/^.*?(?(?=a)a|bc)/
    ba
 0: ba

/^.*?(?(?=a)a(*THEN)b|c)/
    ac
No match

/^.*?(?(?=a)a(*THEN)b)c/
    ac
No match

/^.*?(a(*THEN)b)c/
    aabc
No match
    
/^.*? (?1) c (?(DEFINE)(a(*THEN)b))/x
    aabc
 0: aabc

/^.*?(a(*THEN)b|z)c/
    aabc
 0: aabc
 1: ab

/^.*?(z|a(*THEN)b)c/
    aabc
 0: aabc
 1: ab

# These are here because they are not Perl-compatible; the studying means the
# mark is not seen.

/(*MARK:A)(*SKIP:B)(C|X)/mark
    C
 0: C
 1: C
MK: A
    D
No match, mark = A
     
/(*:A)A+(*SKIP:A)(B|Z)/mark
    AAAC
No match, mark = A

# ----------------------------

"(?=a*(*ACCEPT)b)c"
    c
 0: c
    c\=notempty
 0: c
    
/(?1)c(?(DEFINE)((*ACCEPT)b))/
    c
 0: c
    c\=notempty
 0: c
    
/(?>(*ACCEPT)b)c/
    c
 0: 
    c\=notempty
No match

/(?:(?>(a)))+a%/allaftertext
    %aa%
 0: aa%
 0+ 
 1: a
 1+ a%

/(a)b|ac/allaftertext
    ac\=ovector=1
 0: ac
 0+ 
    
/(a)(b)x|abc/allaftertext
     abc\=ovector=2
 0: abc
 0+ 

/(a)bc|(a)(b)\2/
    abc\=ovector=1
Matched, but too many substrings
 0: abc
    abc\=ovector=2
 0: abc
 1: a
    aba\=ovector=1
Matched, but too many substrings
 0: aba
    aba\=ovector=2
Matched, but too many substrings
 0: aba
 1: <unset>
    aba\=ovector=3
Matched, but too many substrings
 0: aba
 1: <unset>
 2: a
    aba\=ovector=4
 0: aba
 1: <unset>
 2: a
 3: b

/(?(DEFINE)(a(?2)|b)(b(?1)|a))(?:(?1)|(?2))/I
Capturing subpattern count = 2
Subject length lower bound = 1

/(a(?2)|b)(b(?1)|a)(?:(?1)|(?2))/I
Capturing subpattern count = 2
Starting code units: a b 
Subject length lower bound = 3

/(a(?2)|b)(b(?1)|a)(?1)(?2)/I
Capturing subpattern count = 2
Starting code units: a b 
Subject length lower bound = 4

/(abc)(?1)/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 6

/^(?>a)++/
    aa\=find_limits
Minimum match limit = 5
Minimum recursion limit = 2
 0: aa
    aaaaaaaaa\=find_limits
Minimum match limit = 12
Minimum recursion limit = 2
 0: aaaaaaaaa
    
/(a)(?1)++/
    aa\=find_limits
Minimum match limit = 7
Minimum recursion limit = 4
 0: aa
 1: a
    aaaaaaaaa\=find_limits
Minimum match limit = 21
Minimum recursion limit = 4
 0: aaaaaaaaa
 1: a

/(?:(foo)|(bar)|(baz))X/allcaptures
    bazfooX
 0: fooX
 1: foo
 2: <unset>
 3: <unset>
    foobazbarX
 0: barX
 1: <unset>
 2: bar
 3: <unset>
    barfooX
 0: fooX
 1: foo
 2: <unset>
 3: <unset>
    bazX
 0: bazX
 1: <unset>
 2: <unset>
 3: baz
    foobarbazX    
 0: bazX
 1: <unset>
 2: <unset>
 3: baz
    bazfooX\=ovector=0
Matched, but too many substrings
    bazfooX\=ovector=1
Matched, but too many substrings
 0: fooX
    bazfooX\=ovector=2
Matched, but too many substrings
 0: fooX
 1: foo
    bazfooX\=ovector=3
 0: fooX
 1: foo
 2: <unset>

/(?=abc){3}abc/B
------------------------------------------------------------------
        Bra
        Assert
        abc
        Ket
        abc
        Ket
        End
------------------------------------------------------------------

/(?=abc)+abc/B
------------------------------------------------------------------
        Bra
        Assert
        abc
        Ket
        abc
        Ket
        End
------------------------------------------------------------------

/(?=abc)++abc/B
------------------------------------------------------------------
        Bra
        Assert
        abc
        Ket
        abc
        Ket
        End
------------------------------------------------------------------

/(?=abc){0}xyz/B
------------------------------------------------------------------
        Bra
        Skip zero
        Assert
        abc
        Ket
        xyz
        Ket
        End
------------------------------------------------------------------

/(?=(a))?./B
------------------------------------------------------------------
        Bra
        Brazero
        Assert
        CBra 1
        a
        Ket
        Ket
        Any
        Ket
        End
------------------------------------------------------------------

/(?=(a))??./B
------------------------------------------------------------------
        Bra
        Braminzero
        Assert
        CBra 1
        a
        Ket
        Ket
        Any
        Ket
        End
------------------------------------------------------------------

/^(?=(a)){0}b(?1)/B
------------------------------------------------------------------
        Bra
        ^
        Skip zero
        Assert
        CBra 1
        a
        Ket
        Ket
        b
        Recurse
        Ket
        End
------------------------------------------------------------------

/(?(DEFINE)(a))?b(?1)/B
------------------------------------------------------------------
        Bra
        Cond
        Cond false
        CBra 1
        a
        Ket
        Ket
        b
        Recurse
        Ket
        End
------------------------------------------------------------------

/^(?=(?1))?[az]([abc])d/B
------------------------------------------------------------------
        Bra
        ^
        Brazero
        Assert
        Recurse
        Ket
        [az]
        CBra 1
        [a-c]
        Ket
        d
        Ket
        End
------------------------------------------------------------------

/^(?!a){0}\w+/B
------------------------------------------------------------------
        Bra
        ^
        Skip zero
        Assert not
        a
        Ket
        \w++
        Ket
        End
------------------------------------------------------------------

/(?<=(abc))?xyz/B
------------------------------------------------------------------
        Bra
        Brazero
        AssertB
        Reverse
        CBra 1
        abc
        Ket
        Ket
        xyz
        Ket
        End
------------------------------------------------------------------

/[:a[:abc]b:]/B
------------------------------------------------------------------
        Bra
        [:[a-c]
        b:]
        Ket
        End
------------------------------------------------------------------

/((?2))((?1))/
    abc
Failed: error -49: nested recursion at the same subject position

/((?(R2)a+|(?1)b))/
    aaaabcde
Failed: error -49: nested recursion at the same subject position

/(?(R)a*(?1)|((?R))b)/
    aaaabcde
Failed: error -49: nested recursion at the same subject position

/(a+|(?R)b)/
Failed: error 140 at offset 7: recursion could loop indefinitely

/^(a(*:A)(d|e(*:B))z|aeq)/auto_callout
    adz
--->adz
 +0 ^       ^
 +1 ^       (a(*:A)(d|e(*:B))z|aeq)
 +2 ^       a
 +3 ^^      (*:A)
 +8 ^^      (d|e(*:B))
Latest Mark: A
 +9 ^^      d
+10 ^ ^     |
+18 ^ ^     z
+19 ^  ^    |
+24 ^  ^    
 0: adz
 1: adz
 2: d
    aez
--->aez
 +0 ^       ^
 +1 ^       (a(*:A)(d|e(*:B))z|aeq)
 +2 ^       a
 +3 ^^      (*:A)
 +8 ^^      (d|e(*:B))
Latest Mark: A
 +9 ^^      d
+11 ^^      e
+12 ^ ^     (*:B)
+17 ^ ^     )
Latest Mark: B
+18 ^ ^     z
+19 ^  ^    |
+24 ^  ^    
 0: aez
 1: aez
 2: e
    aeqwerty
--->aeqwerty
 +0 ^            ^
 +1 ^            (a(*:A)(d|e(*:B))z|aeq)
 +2 ^            a
 +3 ^^           (*:A)
 +8 ^^           (d|e(*:B))
Latest Mark: A
 +9 ^^           d
+11 ^^           e
+12 ^ ^          (*:B)
+17 ^ ^          )
Latest Mark: B
+18 ^ ^          z
+20 ^            a
+21 ^^           e
+22 ^ ^          q
+23 ^  ^         )
+24 ^  ^         
 0: aeq
 1: aeq

/.(*F)/
    abc\=ph
No match

/\btype\b\W*?\btext\b\W*?\bjavascript\b/I
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = 't'
Last code unit = 't'
Subject length lower bound = 18

/\btype\b\W*?\btext\b\W*?\bjavascript\b|\burl\b\W*?\bshell:|<input\b.*?\btype\b\W*?\bimage\b|\bonkeyup\b\W*?\=/I
Capturing subpattern count = 0
Max lookbehind = 1
Starting code units: < o t u 
Subject length lower bound = 8

/a(*SKIP)c|b(*ACCEPT)|/I,aftertext
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    a
 0: 
 0+ 

/a(*SKIP)c|b(*ACCEPT)cd(*ACCEPT)|x/I
Capturing subpattern count = 0
Starting code units: a b x 
Subject length lower bound = 0
    ax
 0: x

'a*(*ACCEPT)b'aftertext
    \=notempty_atstart
No match
    abc\=notempty_atstart
 0: a
 0+ bc
    bbb\=notempty_atstart
 0: 
 0+ bb

/(*ACCEPT)a/I,aftertext
Capturing subpattern count = 0
Subject length lower bound = 0
    bax
 0: 
 0+ bax

/z(*ACCEPT)a/I,aftertext
Capturing subpattern count = 0
First code unit = 'z'
Subject length lower bound = 0
    baxzbx
 0: z
 0+ bx

/a(?:.)*?a/ims
    abbbbbbbbbbbbbbbbbbbbba\=find_limits
Minimum match limit = 65
Minimum recursion limit = 2
 0: abbbbbbbbbbbbbbbbbbbbba
    
/a(?:.(*THEN))*?a/ims
    abbbbbbbbbbbbbbbbbbbbba\=find_limits
Minimum match limit = 86
Minimum recursion limit = 45
 0: abbbbbbbbbbbbbbbbbbbbba

/a(?:.(*THEN:ABC))*?a/ims
    abbbbbbbbbbbbbbbbbbbbba\=find_limits
Minimum match limit = 86
Minimum recursion limit = 45
 0: abbbbbbbbbbbbbbbbbbbbba

/^(?>a+)(?>(z+))\w/B
------------------------------------------------------------------
        Bra
        ^
        Once_NC
        a++
        Ket
        Once
        CBra 1
        z++
        Ket
        Ket
        \w
        Ket
        End
------------------------------------------------------------------
    aaaazzzzb
 0: aaaazzzzb
 1: zzzz
    ** Failers
No match
    aazz  
No match

/(.)(\1|a(?2))/
    bab
 0: bab
 1: b
 2: ab
    
/\1|(.)(?R)\1/
    cbbbc
 0: cbbbc
 1: c
    
/(.)((?(1)c|a)|a(?2))/
    baa  
No match

/(?P<abn>(?P=abn)xxx)/B
------------------------------------------------------------------
        Bra
        Once
        CBra 1
        \1
        xxx
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------

/(a\1z)/B
------------------------------------------------------------------
        Bra
        Once
        CBra 1
        a
        \1
        z
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------

/^(?>a+)(?>b+)(?>c+)(?>d+)(?>e+)/
     aabbccddee\=find_limits
Minimum match limit = 7
Minimum recursion limit = 2
 0: aabbccddee

/^(?>(a+))(?>(b+))(?>(c+))(?>(d+))(?>(e+))/
     aabbccddee\=find_limits
Minimum match limit = 17
Minimum recursion limit = 16
 0: aabbccddee
 1: aa
 2: bb
 3: cc
 4: dd
 5: ee

/^(?>(a+))(?>b+)(?>(c+))(?>d+)(?>(e+))/
     aabbccddee\=find_limits
Minimum match limit = 13
Minimum recursion limit = 10
 0: aabbccddee
 1: aa
 2: cc
 3: ee

/^a\x41z/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    aAz
 0: aAz
    *** Failers
No match
    ax41z
No match

/^a[m\x41]z/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    aAz
 0: aAz

/^a\x1z/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    ax1z
 0: ax1z

/^a\u0041z/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    aAz
 0: aAz
    *** Failers
No match
    au0041z
No match

/^a[m\u0041]z/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    aAz
 0: aAz

/^a\u041z/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    au041z
 0: au041z
    *** Failers
No match
    aAz
No match

/^a\U0041z/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    aU0041z
 0: aU0041z
    *** Failers
No match
    aAz
No match

/(?(?=c)c|d)++Y/B
------------------------------------------------------------------
        Bra
        BraPos
        Cond
        Assert
        c
        Ket
        c
        Alt
        d
        Ket
        KetRpos
        Y
        Ket
        End
------------------------------------------------------------------

/(?(?=c)c|d)*+Y/B
------------------------------------------------------------------
        Bra
        Braposzero
        BraPos
        Cond
        Assert
        c
        Ket
        c
        Alt
        d
        Ket
        KetRpos
        Y
        Ket
        End
------------------------------------------------------------------

/a[\NB]c/
Failed: error 171 at offset 3: \N is not supported in a class
    aNc
    
/a[B-\Nc]/
Failed: error 150 at offset 5: invalid range in character class

/a[B\Nc]/
Failed: error 171 at offset 4: \N is not supported in a class

/(a)(?2){0,1999}?(b)/

/(a)(?(DEFINE)(b))(?2){0,1999}?(?2)/

# This test, with something more complicated than individual letters, causes
# different behaviour in Perl. Perhaps it disables some optimization; no tag is
# passed back for the failures, whereas in PCRE2 there is a tag.
    
/(A|P)(*:A)(B|P) | (X|P)(X|P)(*:B)(Y|P)/x,mark
    AABC
 0: AB
 1: A
 2: B
MK: A
    XXYZ 
 0: XXY
 1: <unset>
 2: <unset>
 3: X
 4: X
 5: Y
MK: B
    ** Failers
No match
    XAQQ  
No match, mark = A
    XAQQXZZ  
No match, mark = A
    AXQQQ 
No match, mark = A
    AXXQQQ 
No match, mark = B

# Perl doesn't give marks for these, though it does if the alternatives are
# replaced by single letters. 
    
/(b|q)(*:m)f|a(*:n)w/mark
    aw 
 0: aw
MK: n
    ** Failers 
No match, mark = n
    abc
No match, mark = m

/(q|b)(*:m)f|a(*:n)w/mark
    aw 
 0: aw
MK: n
    ** Failers 
No match, mark = n
    abc
No match, mark = m

# After a partial match, the behaviour is as for a failure. 

/^a(*:X)bcde/mark
   abc\=ps
Partial match, mark=X: abc
   
# These are here because Perl doesn't return a mark, except for the first.

/(?=(*:x))(q|)/aftertext,mark
    abc
 0: 
 0+ abc
 1: 
MK: x

/(?=(*:x))((*:y)q|)/aftertext,mark
    abc
 0: 
 0+ abc
 1: 
MK: x

/(?=(*:x))(?:(*:y)q|)/aftertext,mark
    abc
 0: 
 0+ abc
MK: x

/(?=(*:x))(?>(*:y)q|)/aftertext,mark
    abc
 0: 
 0+ abc
MK: x

/(?=a(*:x))(?!a(*:y)c)/aftertext,mark
    ab
 0: 
 0+ ab
MK: x

/(?=a(*:x))(?=a(*:y)c|)/aftertext,mark
    ab
 0: 
 0+ ab
MK: x

/(..)\1/
    ab\=ps
Partial match: ab
    aba\=ps
Partial match: aba
    abab\=ps
 0: abab
 1: ab

/(..)\1/i
    ab\=ps
Partial match: ab
    abA\=ps
Partial match: abA
    aBAb\=ps
 0: aBAb
 1: aB

/(..)\1{2,}/
    ab\=ps
Partial match: ab
    aba\=ps
Partial match: aba
    abab\=ps
Partial match: abab
    ababa\=ps
Partial match: ababa
    ababab\=ps
 0: ababab
 1: ab
    ababab\=ph
Partial match: ababab
    abababa\=ps
 0: ababab
 1: ab
    abababa\=ph
Partial match: abababa

/(..)\1{2,}/i
    ab\=ps
Partial match: ab
    aBa\=ps
Partial match: aBa
    aBAb\=ps
Partial match: aBAb
    AbaBA\=ps
Partial match: AbaBA
    abABAb\=ps
 0: abABAb
 1: ab
    aBAbaB\=ph
Partial match: aBAbaB
    abABabA\=ps
 0: abABab
 1: ab
    abaBABa\=ph
Partial match: abaBABa

/(..)\1{2,}?x/i
    ab\=ps
Partial match: ab
    abA\=ps
Partial match: abA
    aBAb\=ps
Partial match: aBAb
    abaBA\=ps
Partial match: abaBA
    abAbaB\=ps
Partial match: abAbaB
    abaBabA\=ps
Partial match: abaBabA
    abAbABaBx\=ps
 0: abAbABaBx
 1: ab

/^(..)\1/
    aba\=ps
Partial match: aba

/^(..)\1{2,3}x/
    aba\=ps
Partial match: aba
    ababa\=ps
Partial match: ababa
    ababa\=ph
Partial match: ababa
    abababx
 0: abababx
 1: ab
    ababababx  
 0: ababababx
 1: ab

/^(..)\1{2,3}?x/
    aba\=ps
Partial match: aba
    ababa\=ps
Partial match: ababa
    ababa\=ph
Partial match: ababa
    abababx
 0: abababx
 1: ab
    ababababx  
 0: ababababx
 1: ab
    
/^(..)(\1{2,3})ab/
    abababab
 0: abababab
 1: ab
 2: abab

/^\R/
    \r\=ps
 0: \x0d
    \r\=ph
Partial match: \x0d
    
/^\R{2,3}x/
    \r\=ps
Partial match: \x0d
    \r\=ph
Partial match: \x0d
    \r\r\=ps
Partial match: \x0d\x0d
    \r\r\=ph
Partial match: \x0d\x0d
    \r\r\r\=ps
Partial match: \x0d\x0d\x0d
    \r\r\r\=ph
Partial match: \x0d\x0d\x0d
    \r\rx
 0: \x0d\x0dx
    \r\r\rx    
 0: \x0d\x0d\x0dx

/^\R{2,3}?x/
    \r\=ps
Partial match: \x0d
    \r\=ph
Partial match: \x0d
    \r\r\=ps
Partial match: \x0d\x0d
    \r\r\=ph
Partial match: \x0d\x0d
    \r\r\r\=ps
Partial match: \x0d\x0d\x0d
    \r\r\r\=ph
Partial match: \x0d\x0d\x0d
    \r\rx
 0: \x0d\x0dx
    \r\r\rx    
 0: \x0d\x0d\x0dx
    
/^\R?x/
    \r\=ps
Partial match: \x0d
    \r\=ph
Partial match: \x0d
    x
 0: x
    \rx  
 0: \x0dx

/^\R+x/
    \r\=ps
Partial match: \x0d
    \r\=ph
Partial match: \x0d
    \r\n\=ps
Partial match: \x0d\x0a
    \r\n\=ph
Partial match: \x0d\x0a
    \rx  
 0: \x0dx

/^a$/newline=crlf
    a\r\=ps
Partial match: a\x0d
    a\r\=ph
Partial match: a\x0d

/^a$/m,newline=crlf
    a\r\=ps
Partial match: a\x0d
    a\r\=ph
Partial match: a\x0d

/^(a$|a\r)/newline=crlf
    a\r\=ps
 0: a\x0d
 1: a\x0d
    a\r\=ph
Partial match: a\x0d

/^(a$|a\r)/m,newline=crlf
    a\r\=ps
 0: a\x0d
 1: a\x0d
    a\r\=ph
Partial match: a\x0d

/./newline=crlf
    \r\=ps
 0: \x0d
    \r\=ph
Partial match: \x0d
  
/.{2,3}/newline=crlf
    \r\=ps
Partial match: \x0d
    \r\=ph
Partial match: \x0d
    \r\r\=ps
 0: \x0d\x0d
    \r\r\=ph
Partial match: \x0d\x0d
    \r\r\r\=ps
 0: \x0d\x0d\x0d
    \r\r\r\=ph
Partial match: \x0d\x0d\x0d

/.{2,3}?/newline=crlf
    \r\=ps
Partial match: \x0d
    \r\=ph
Partial match: \x0d
    \r\r\=ps
 0: \x0d\x0d
    \r\r\=ph
Partial match: \x0d\x0d
    \r\r\r\=ps
 0: \x0d\x0d
    \r\r\r\=ph
 0: \x0d\x0d

"AB(C(D))(E(F))?(?(?=\2)(?=\4))"
    ABCDGHI\=ovector=01
Matched, but too many substrings
 0: ABCD
    
# These are all run as real matches in test 1; here we are just checking the
# settings of the anchored and startline bits.  

/(?>.*?a)(?<=ba)/I
Capturing subpattern count = 0
Max lookbehind = 2
Last code unit = 'a'
Subject length lower bound = 1

/(?:.*?a)(?<=ba)/I
Capturing subpattern count = 0
Max lookbehind = 2
First code unit at start or follows newline
Last code unit = 'a'
Subject length lower bound = 1

/.*?a(*PRUNE)b/I
Capturing subpattern count = 0
Last code unit = 'b'
Subject length lower bound = 2

/.*?a(*PRUNE)b/Is
Capturing subpattern count = 0
Options: dotall
Last code unit = 'b'
Subject length lower bound = 2

/^a(*PRUNE)b/Is
Capturing subpattern count = 0
Compile options: dotall
Overall options: anchored dotall
Subject length lower bound = 2

/.*?a(*SKIP)b/I
Capturing subpattern count = 0
Last code unit = 'b'
Subject length lower bound = 2

/(?>.*?a)b/Is
Capturing subpattern count = 0
Options: dotall
Last code unit = 'b'
Subject length lower bound = 2

/(?>.*?a)b/I
Capturing subpattern count = 0
Last code unit = 'b'
Subject length lower bound = 2

/(?>^a)b/Is
Capturing subpattern count = 0
Compile options: dotall
Overall options: anchored dotall
Subject length lower bound = 2

/(?>.*?)(?<=(abcd)|(wxyz))/I
Capturing subpattern count = 2
Max lookbehind = 4
May match empty string
Subject length lower bound = 0

/(?>.*)(?<=(abcd)|(wxyz))/I
Capturing subpattern count = 2
Max lookbehind = 4
May match empty string
Subject length lower bound = 0

"(?>.*)foo"I
Capturing subpattern count = 0
Last code unit = 'o'
Subject length lower bound = 3

"(?>.*?)foo"I
Capturing subpattern count = 0
Last code unit = 'o'
Subject length lower bound = 3

/(?>^abc)/Im
Capturing subpattern count = 0
Options: multiline
First code unit at start or follows newline
Last code unit = 'c'
Subject length lower bound = 3

/(?>.*abc)/Im
Capturing subpattern count = 0
Options: multiline
Last code unit = 'c'
Subject length lower bound = 3

/(?:.*abc)/Im
Capturing subpattern count = 0
Options: multiline
First code unit at start or follows newline
Last code unit = 'c'
Subject length lower bound = 3

/(?:(a)+(?C1)bb|aa(?C2)b)/
    aab\=callout_capture
Callout 1: last capture = 1
 0: <unset>
 1: a
--->aab
    ^ ^     b
Callout 1: last capture = 1
 0: <unset>
 1: a
--->aab
    ^^      b
Callout 2: last capture = 0
 0: <unset>
--->aab
    ^ ^     b
 0: aab
   
/(?:(a)++(?C1)bb|aa(?C2)b)/
    aab\=callout_capture
Callout 1: last capture = 1
 0: <unset>
 1: a
--->aab
    ^ ^     b
Callout 2: last capture = 0
 0: <unset>
--->aab
    ^ ^     b
 0: aab
    
/(?:(?>(a))(?C1)bb|aa(?C2)b)/
    aab\=callout_capture
Callout 1: last capture = 1
 0: <unset>
 1: a
--->aab
    ^^      b
Callout 2: last capture = 0
 0: <unset>
--->aab
    ^ ^     b
 0: aab

/(?:(?1)(?C1)x|ab(?C2))((a)){0}/
    aab\=callout_capture
Callout 1: last capture = 0
 0: <unset>
--->aab
    ^^      x
Callout 1: last capture = 0
 0: <unset>
--->aab
     ^^     x
Callout 2: last capture = 0
 0: <unset>
--->aab
     ^ ^    )
 0: ab

/(?1)(?C1)((a)(?C2)){0}/
    aab\=callout_capture
Callout 2: last capture = 2
 0: <unset>
 1: <unset>
 2: a
--->aab
    ^^      )
Callout 1: last capture = 0
 0: <unset>
--->aab
    ^^      ((a)(?C2)){0}
 0: a

/(?:(a)+(?C1)bb|aa(?C2)b)++/
    aab\=callout_capture
Callout 1: last capture = 1
 0: <unset>
 1: a
--->aab
    ^ ^     b
Callout 1: last capture = 1
 0: <unset>
 1: a
--->aab
    ^^      b
Callout 2: last capture = 0
 0: <unset>
--->aab
    ^ ^     b
 0: aab
    aab\=callout_capture,ovector=1
Callout 1: last capture = 1
 0: <unset>
--->aab
    ^ ^     b
Callout 1: last capture = 1
 0: <unset>
--->aab
    ^^      b
Callout 2: last capture = 0
 0: <unset>
--->aab
    ^ ^     b
 0: aab

/(ab)x|ab/
    ab\=ovector=0
Matched, but too many substrings
    ab\=ovector=1
 0: ab
  
/(?<=123)(*MARK:xx)abc/mark
    xxxx123a\=ph
Partial match at offset 7, mark=xx: 123a
    xxxx123a\=ps
Partial match at offset 7, mark=xx: 123a
    
/123\Kabc/
    xxxx123a\=ph
Partial match: 123a
    xxxx123a\=ps
Partial match: 123a

/^(?(?=a)aa|bb)/auto_callout
    bb
--->bb
 +0 ^      ^
 +1 ^      (?(?=a)aa|bb)
 +3 ^      (?=a)
 +6 ^      a
+11 ^      b
+12 ^^     b
+13 ^ ^    )
+14 ^ ^    
 0: bb

/(?C1)^(?C2)(?(?C99)(?=(?C3)a(?C4))(?C5)a(?C6)a(?C7)|(?C8)b(?C9)b(?C10))(?C11)/
    bb
--->bb
  1 ^      ^
  2 ^      (?(?C99)(?=(?C3)a(?C4))(?C5)a(?C6)a(?C7)|(?C8)b(?C9)b(?C10))
 99 ^      (?=(?C3)a(?C4))
  3 ^      a
  8 ^      b
  9 ^^     b
 10 ^ ^    )
 11 ^ ^    
 0: bb

# Perl seems to have a bug with this one.

/aaaaa(*COMMIT)(*PRUNE)b|a+c/
    aaaaaac
 0: aaaac
    
# Here are some that Perl treats differently because of the way it handles
# backtracking verbs. 

/(?!a(*COMMIT)b)ac|ad/
     ac
 0: ac
     ad 
 0: ad

/^(?!a(*THEN)b|ac)../
     ac
No match
     ad 
 0: ad

/^(?=a(*THEN)b|ac)/
    ac
 0: 
    
/\A.*?(?:a|b(*THEN)c)/
    ba
 0: ba

/\A.*?(?:a|b(*THEN)c)++/
    ba
 0: ba

/\A.*?(?:a|b(*THEN)c|d)/
    ba
 0: ba

/(?:(a(*MARK:X)a+(*SKIP:X)b)){0}(?:(?1)|aac)/
    aac 
 0: aac

/\A.*?(a|b(*THEN)c)/
    ba
 0: ba
 1: a

/^(A(*THEN)B|A(*THEN)D)/
    AD           
 0: AD
 1: AD
    
/(?!b(*THEN)a)bn|bnn/
    bnn
 0: bn

/(?(?=b(*SKIP)a)bn|bnn)/
    bnn
No match

/(?=b(*THEN)a|)bn|bnn/
    bnn
 0: bn

# --------------------- 

/(*LIMIT_MATCH=12bc)abc/
Failed: error 160 at offset 0: (*VERB) not recognized or malformed

/(*LIMIT_MATCH=4294967290)abc/
Failed: error 160 at offset 0: (*VERB) not recognized or malformed

/(*LIMIT_RECURSION=4294967280)abc/I
Capturing subpattern count = 0
Recursion limit = 4294967280
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3

/(a+)*zz/
    aaaaaaaaaaaaaz
No match
    aaaaaaaaaaaaaz\=match_limit=3000
Failed: error -45: match limit exceeded

/(a+)*zz/
    aaaaaaaaaaaaaz\=recursion_limit=10
Failed: error -50: recursion limit exceeded

/(*LIMIT_MATCH=3000)(a+)*zz/I
Capturing subpattern count = 1
Match limit = 3000
Starting code units: a z 
Last code unit = 'z'
Subject length lower bound = 2
    aaaaaaaaaaaaaz
Failed: error -45: match limit exceeded
    aaaaaaaaaaaaaz\=match_limit=60000
Failed: error -45: match limit exceeded

/(*LIMIT_MATCH=60000)(*LIMIT_MATCH=3000)(a+)*zz/I
Capturing subpattern count = 1
Match limit = 3000
Starting code units: a z 
Last code unit = 'z'
Subject length lower bound = 2
    aaaaaaaaaaaaaz
Failed: error -45: match limit exceeded

/(*LIMIT_MATCH=60000)(a+)*zz/I
Capturing subpattern count = 1
Match limit = 60000
Starting code units: a z 
Last code unit = 'z'
Subject length lower bound = 2
    aaaaaaaaaaaaaz
No match
    aaaaaaaaaaaaaz\=match_limit=3000
Failed: error -45: match limit exceeded

/(*LIMIT_RECURSION=10)(a+)*zz/I
Capturing subpattern count = 1
Recursion limit = 10
Starting code units: a z 
Last code unit = 'z'
Subject length lower bound = 2
    aaaaaaaaaaaaaz
Failed: error -50: recursion limit exceeded
    aaaaaaaaaaaaaz\=recursion_limit=1000
Failed: error -50: recursion limit exceeded

/(*LIMIT_RECURSION=10)(*LIMIT_RECURSION=1000)(a+)*zz/I
Capturing subpattern count = 1
Recursion limit = 1000
Starting code units: a z 
Last code unit = 'z'
Subject length lower bound = 2
    aaaaaaaaaaaaaz
No match

/(*LIMIT_RECURSION=1000)(a+)*zz/I
Capturing subpattern count = 1
Recursion limit = 1000
Starting code units: a z 
Last code unit = 'z'
Subject length lower bound = 2
    aaaaaaaaaaaaaz
No match
    aaaaaaaaaaaaaz\=recursion_limit=10
Failed: error -50: recursion limit exceeded

# This test causes a segfault with Perl 5.18.0 

/^(?=(a)){0}b(?1)/
    backgammon
 0: ba

/(?|(?<n>f)|(?<n>b))/I,dupnames
Capturing subpattern count = 1
Named capturing subpatterns:
  n   1
Options: dupnames
Starting code units: b f 
Subject length lower bound = 1

/(?<a>abc)(?<a>z)\k<a>()/IB,dupnames
------------------------------------------------------------------
        Bra
        CBra 1
        abc
        Ket
        CBra 2
        z
        Ket
        \k<a>2
        CBra 3
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 3
Max back reference = 2
Named capturing subpatterns:
  a   1
  a   2
Options: dupnames
First code unit = 'a'
Last code unit = 'z'
Subject length lower bound = 5

/a*[bcd]/B
------------------------------------------------------------------
        Bra
        a*+
        [b-d]
        Ket
        End
------------------------------------------------------------------

/[bcd]*a/B
------------------------------------------------------------------
        Bra
        [b-d]*+
        a
        Ket
        End
------------------------------------------------------------------

# A complete set of tests for auto-possessification of character types.

/\D+\D \D+\d \D+\S \D+\s \D+\W \D+\w \D+. \D+\C \D+\R \D+\H \D+\h \D+\V \D+\v \D+\Z \D+\z \D+$/Bx
------------------------------------------------------------------
        Bra
        \D+
        \D
        \D++
        \d
        \D+
        \S
        \D+
        \s
        \D+
        \W
        \D+
        \w
        \D+
        Any
        \D+
        AllAny
        \D+
        \R
        \D+
        \H
        \D+
        \h
        \D+
        \V
        \D+
        \v
        \D+
        \Z
        \D++
        \z
        \D+
        $
        Ket
        End
------------------------------------------------------------------

/\d+\D \d+\d \d+\S \d+\s \d+\W \d+\w \d+. \d+\C \d+\R \d+\H \d+\h \d+\V \d+\v \d+\Z \d+\z \d+$/Bx
------------------------------------------------------------------
        Bra
        \d++
        \D
        \d+
        \d
        \d+
        \S
        \d++
        \s
        \d++
        \W
        \d+
        \w
        \d+
        Any
        \d+
        AllAny
        \d++
        \R
        \d+
        \H
        \d++
        \h
        \d+
        \V
        \d++
        \v
        \d++
        \Z
        \d++
        \z
        \d++
        $
        Ket
        End
------------------------------------------------------------------

/\S+\D \S+\d \S+\S \S+\s \S+\W \S+\w \S+. \S+\C \S+\R \S+\H \S+\h \S+\V \S+\v \S+\Z \S+\z \S+$/Bx
------------------------------------------------------------------
        Bra
        \S+
        \D
        \S+
        \d
        \S+
        \S
        \S++
        \s
        \S+
        \W
        \S+
        \w
        \S+
        Any
        \S+
        AllAny
        \S++
        \R
        \S+
        \H
        \S++
        \h
        \S+
        \V
        \S++
        \v
        \S++
        \Z
        \S++
        \z
        \S++
        $
        Ket
        End
------------------------------------------------------------------

/\s+\D \s+\d \s+\S \s+\s \s+\W \s+\w \s+. \s+\C \s+\R \s+\H \s+\h \s+\V \s+\v \s+\Z \s+\z \s+$/Bx
------------------------------------------------------------------
        Bra
        \s+
        \D
        \s++
        \d
        \s++
        \S
        \s+
        \s
        \s+
        \W
        \s++
        \w
        \s+
        Any
        \s+
        AllAny
        \s+
        \R
        \s+
        \H
        \s+
        \h
        \s+
        \V
        \s+
        \v
        \s+
        \Z
        \s++
        \z
        \s+
        $
        Ket
        End
------------------------------------------------------------------

/\W+\D \W+\d \W+\S \W+\s \W+\W \W+\w \W+. \W+\C \W+\R \W+\H \W+\h \W+\V \W+\v \W+\Z \W+\z \W+$/Bx
------------------------------------------------------------------
        Bra
        \W+
        \D
        \W++
        \d
        \W+
        \S
        \W+
        \s
        \W+
        \W
        \W++
        \w
        \W+
        Any
        \W+
        AllAny
        \W+
        \R
        \W+
        \H
        \W+
        \h
        \W+
        \V
        \W+
        \v
        \W+
        \Z
        \W++
        \z
        \W+
        $
        Ket
        End
------------------------------------------------------------------

/\w+\D \w+\d \w+\S \w+\s \w+\W \w+\w \w+. \w+\C \w+\R \w+\H \w+\h \w+\V \w+\v \w+\Z \w+\z \w+$/Bx
------------------------------------------------------------------
        Bra
        \w+
        \D
        \w+
        \d
        \w+
        \S
        \w++
        \s
        \w++
        \W
        \w+
        \w
        \w+
        Any
        \w+
        AllAny
        \w++
        \R
        \w+
        \H
        \w++
        \h
        \w+
        \V
        \w++
        \v
        \w++
        \Z
        \w++
        \z
        \w++
        $
        Ket
        End
------------------------------------------------------------------

/\C+\D \C+\d \C+\S \C+\s \C+\W \C+\w \C+. \C+\C \C+\R \C+\H \C+\h \C+\V \C+\v \C+\Z \C+\z \C+$/Bx
------------------------------------------------------------------
        Bra
        AllAny+
        \D
        AllAny+
        \d
        AllAny+
        \S
        AllAny+
        \s
        AllAny+
        \W
        AllAny+
        \w
        AllAny+
        Any
        AllAny+
        AllAny
        AllAny+
        \R
        AllAny+
        \H
        AllAny+
        \h
        AllAny+
        \V
        AllAny+
        \v
        AllAny+
        \Z
        AllAny++
        \z
        AllAny+
        $
        Ket
        End
------------------------------------------------------------------

/\R+\D \R+\d \R+\S \R+\s \R+\W \R+\w \R+. \R+\C \R+\R \R+\H \R+\h \R+\V \R+\v \R+\Z \R+\z \R+$/Bx
------------------------------------------------------------------
        Bra
        \R+
        \D
        \R++
        \d
        \R+
        \S
        \R++
        \s
        \R+
        \W
        \R++
        \w
        \R++
        Any
        \R+
        AllAny
        \R+
        \R
        \R+
        \H
        \R++
        \h
        \R+
        \V
        \R+
        \v
        \R+
        \Z
        \R++
        \z
        \R+
        $
        Ket
        End
------------------------------------------------------------------

/\H+\D \H+\d \H+\S \H+\s \H+\W \H+\w \H+. \H+\C \H+\R \H+\H \H+\h \H+\V \H+\v \H+\Z \H+\z \H+$/Bx
------------------------------------------------------------------
        Bra
        \H+
        \D
        \H+
        \d
        \H+
        \S
        \H+
        \s
        \H+
        \W
        \H+
        \w
        \H+
        Any
        \H+
        AllAny
        \H+
        \R
        \H+
        \H
        \H++
        \h
        \H+
        \V
        \H+
        \v
        \H+
        \Z
        \H++
        \z
        \H+
        $
        Ket
        End
------------------------------------------------------------------

/\h+\D \h+\d \h+\S \h+\s \h+\W \h+\w \h+. \h+\C \h+\R \h+\H \h+\h \h+\V \h+\v \h+\Z \h+\z \h+$/Bx
------------------------------------------------------------------
        Bra
        \h+
        \D
        \h++
        \d
        \h++
        \S
        \h+
        \s
        \h+
        \W
        \h++
        \w
        \h+
        Any
        \h+
        AllAny
        \h++
        \R
        \h++
        \H
        \h+
        \h
        \h+
        \V
        \h++
        \v
        \h+
        \Z
        \h++
        \z
        \h+
        $
        Ket
        End
------------------------------------------------------------------

/\V+\D \V+\d \V+\S \V+\s \V+\W \V+\w \V+. \V+\C \V+\R \V+\H \V+\h \V+\V \V+\v \V+\Z \V+\z \V+$/Bx
------------------------------------------------------------------
        Bra
        \V+
        \D
        \V+
        \d
        \V+
        \S
        \V+
        \s
        \V+
        \W
        \V+
        \w
        \V+
        Any
        \V+
        AllAny
        \V++
        \R
        \V+
        \H
        \V+
        \h
        \V+
        \V
        \V++
        \v
        \V+
        \Z
        \V++
        \z
        \V+
        $
        Ket
        End
------------------------------------------------------------------

/\v+\D \v+\d \v+\S \v+\s \v+\W \v+\w \v+. \v+\C \v+\R \v+\H \v+\h \v+\V \v+\v \v+\Z \v+\z \v+$/Bx
------------------------------------------------------------------
        Bra
        \v+
        \D
        \v++
        \d
        \v++
        \S
        \v+
        \s
        \v+
        \W
        \v++
        \w
        \v+
        Any
        \v+
        AllAny
        \v+
        \R
        \v+
        \H
        \v++
        \h
        \v++
        \V
        \v+
        \v
        \v+
        \Z
        \v++
        \z
        \v+
        $
        Ket
        End
------------------------------------------------------------------

/ a+\D  a+\d  a+\S  a+\s  a+\W  a+\w  a+.  a+\C  a+\R  a+\H  a+\h  a+\V  a+\v  a+\Z  a+\z  a+$/Bx
------------------------------------------------------------------
        Bra
        a+
        \D
        a++
        \d
        a+
        \S
        a++
        \s
        a++
        \W
        a+
        \w
        a+
        Any
        a+
        AllAny
        a++
        \R
        a+
        \H
        a++
        \h
        a+
        \V
        a++
        \v
        a++
        \Z
        a++
        \z
        a++
        $
        Ket
        End
------------------------------------------------------------------

/\n+\D \n+\d \n+\S \n+\s \n+\W \n+\w \n+. \n+\C \n+\R \n+\H \n+\h \n+\V \n+\v \n+\Z \n+\z \n+$/Bx
------------------------------------------------------------------
        Bra
        \x0a+
        \D
        \x0a++
        \d
        \x0a++
        \S
        \x0a+
        \s
        \x0a+
        \W
        \x0a++
        \w
        \x0a+
        Any
        \x0a+
        AllAny
        \x0a+
        \R
        \x0a+
        \H
        \x0a++
        \h
        \x0a++
        \V
        \x0a+
        \v
        \x0a+
        \Z
        \x0a++
        \z
        \x0a+
        $
        Ket
        End
------------------------------------------------------------------

/ .+\D  .+\d  .+\S  .+\s  .+\W  .+\w  .+.  .+\C  .+\R  .+\H  .+\h  .+\V  .+\v  .+\Z  .+\z  .+$/Bx
------------------------------------------------------------------
        Bra
        Any+
        \D
        Any+
        \d
        Any+
        \S
        Any+
        \s
        Any+
        \W
        Any+
        \w
        Any+
        Any
        Any+
        AllAny
        Any++
        \R
        Any+
        \H
        Any+
        \h
        Any+
        \V
        Any+
        \v
        Any+
        \Z
        Any++
        \z
        Any+
        $
        Ket
        End
------------------------------------------------------------------

/ .+\D  .+\d  .+\S  .+\s  .+\W  .+\w  .+.  .+\C  .+\R  .+\H  .+\h  .+\V  .+\v  .+\Z  .+\z  .+$/Bsx
------------------------------------------------------------------
        Bra
        AllAny+
        \D
        AllAny+
        \d
        AllAny+
        \S
        AllAny+
        \s
        AllAny+
        \W
        AllAny+
        \w
        AllAny+
        AllAny
        AllAny+
        AllAny
        AllAny+
        \R
        AllAny+
        \H
        AllAny+
        \h
        AllAny+
        \V
        AllAny+
        \v
        AllAny+
        \Z
        AllAny++
        \z
        AllAny+
        $
        Ket
        End
------------------------------------------------------------------

/\D+$  \d+$  \S+$  \s+$  \W+$  \w+$  \C+$  \R+$  \H+$  \h+$  \V+$  \v+$   a+$  \n+$   .+$  .+$/Bmx
------------------------------------------------------------------
        Bra
        \D+
     /m $
        \d++
     /m $
        \S++
     /m $
        \s+
     /m $
        \W+
     /m $
        \w++
     /m $
        AllAny+
     /m $
        \R+
     /m $
        \H+
     /m $
        \h+
     /m $
        \V+
     /m $
        \v+
     /m $
        a+
     /m $
        \x0a+
     /m $
        Any+
     /m $
        Any+
     /m $
        Ket
        End
------------------------------------------------------------------

/(?=a+)a(a+)++a/B
------------------------------------------------------------------
        Bra
        Assert
        a++
        Ket
        a
        CBraPos 1
        a++
        KetRpos
        a
        Ket
        End
------------------------------------------------------------------

/a+(bb|cc)a+(?:bb|cc)a+(?>bb|cc)a+(?:bb|cc)+a+(aa)a+(?:bb|aa)/B
------------------------------------------------------------------
        Bra
        a++
        CBra 1
        bb
        Alt
        cc
        Ket
        a++
        Bra
        bb
        Alt
        cc
        Ket
        a++
        Once_NC
        bb
        Alt
        cc
        Ket
        a++
        Bra
        bb
        Alt
        cc
        KetRmax
        a+
        CBra 2
        aa
        Ket
        a+
        Bra
        bb
        Alt
        aa
        Ket
        Ket
        End
------------------------------------------------------------------

/a+(bb|cc)?#a+(?:bb|cc)??#a+(?:bb|cc)?+#a+(?:bb|cc)*#a+(bb|cc)?a#a+(?:aa)?/B
------------------------------------------------------------------
        Bra
        a++
        Brazero
        CBra 1
        bb
        Alt
        cc
        Ket
        #
        a++
        Braminzero
        Bra
        bb
        Alt
        cc
        Ket
        #
        a++
        Once
        Brazero
        Bra
        bb
        Alt
        cc
        Ket
        Ket
        #
        a++
        Brazero
        Bra
        bb
        Alt
        cc
        KetRmax
        #
        a+
        Brazero
        CBra 2
        bb
        Alt
        cc
        Ket
        a#
        a+
        Brazero
        Bra
        aa
        Ket
        Ket
        End
------------------------------------------------------------------

/a+(?:bb)?a#a+(?:|||)#a+(?:|b)a#a+(?:|||)?a/B
------------------------------------------------------------------
        Bra
        a+
        Brazero
        Bra
        bb
        Ket
        a#
        a++
        Bra
        Alt
        Alt
        Alt
        Ket
        #
        a+
        Bra
        Alt
        b
        Ket
        a#
        a+
        Brazero
        Bra
        Alt
        Alt
        Alt
        Ket
        a
        Ket
        End
------------------------------------------------------------------

/[ab]*/B
------------------------------------------------------------------
        Bra
        [ab]*+
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: aaaa

/[ab]*?/B
------------------------------------------------------------------
        Bra
        [ab]*?
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: 

/[ab]?/B
------------------------------------------------------------------
        Bra
        [ab]?+
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: a

/[ab]??/B
------------------------------------------------------------------
        Bra
        [ab]??
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: 

/[ab]+/B
------------------------------------------------------------------
        Bra
        [ab]++
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: aaaa

/[ab]+?/B
------------------------------------------------------------------
        Bra
        [ab]+?
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: a

/[ab]{2,3}/B
------------------------------------------------------------------
        Bra
        [ab]{2,3}+
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: aaa

/[ab]{2,3}?/B
------------------------------------------------------------------
        Bra
        [ab]{2,3}?
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: aa

/[ab]{2,}/B
------------------------------------------------------------------
        Bra
        [ab]{2,}+
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: aaaa

/[ab]{2,}?/B
------------------------------------------------------------------
        Bra
        [ab]{2,}?
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: aa

/\d+\s{0,5}=\s*\S?=\w{0,4}\W*/B
------------------------------------------------------------------
        Bra
        \d++
        \s{0,5}+
        =
        \s*+
        \S?
        =
        \w{0,4}+
        \W*+
        Ket
        End
------------------------------------------------------------------

/[a-d]{5,12}[e-z0-9]*#[^a-z]+[b-y]*a[2-7]?[^0-9a-z]+/B
------------------------------------------------------------------
        Bra
        [a-d]{5,12}+
        [0-9e-z]*+
        #
        [\x00-`{-\xff] (neg)++
        [b-y]*+
        a
        [2-7]?+
        [\x00-/:-`{-\xff] (neg)++
        Ket
        End
------------------------------------------------------------------

/[a-z]*\s#[ \t]?\S#[a-c]*\S#[C-G]+?\d#[4-8]*\D#[4-9,]*\D#[!$]{0,5}\w#[M-Xf-l]+\W#[a-c,]?\W/B
------------------------------------------------------------------
        Bra
        [a-z]*+
        \s
        #
        [\x09 ]?+
        \S
        #
        [a-c]*
        \S
        #
        [C-G]++
        \d
        #
        [4-8]*+
        \D
        #
        [,4-9]*
        \D
        #
        [!$]{0,5}+
        \w
        #
        [M-Xf-l]++
        \W
        #
        [,a-c]?
        \W
        Ket
        End
------------------------------------------------------------------

/a+(aa|bb)*c#a*(bb|cc)*a#a?(bb|cc)*d#[a-f]*(g|hh)*f/B
------------------------------------------------------------------
        Bra
        a+
        Brazero
        CBra 1
        aa
        Alt
        bb
        KetRmax
        c#
        a*
        Brazero
        CBra 2
        bb
        Alt
        cc
        KetRmax
        a#
        a?+
        Brazero
        CBra 3
        bb
        Alt
        cc
        KetRmax
        d#
        [a-f]*
        Brazero
        CBra 4
        g
        Alt
        hh
        KetRmax
        f
        Ket
        End
------------------------------------------------------------------

/[a-f]*(g|hh|i)*i#[a-x]{4,}(y{0,6})*y#[a-k]+(ll|mm)+n/B
------------------------------------------------------------------
        Bra
        [a-f]*+
        Brazero
        CBra 1
        g
        Alt
        hh
        Alt
        i
        KetRmax
        i#
        [a-x]{4,}
        Brazero
        SCBra 2
        y{0,6}
        KetRmax
        y#
        [a-k]++
        CBra 3
        ll
        Alt
        mm
        KetRmax
        n
        Ket
        End
------------------------------------------------------------------

/[a-f]*(?>gg|hh)+#[a-f]*(?>gg|hh)?#[a-f]*(?>gg|hh)*a#[a-f]*(?>gg|hh)*h/B
------------------------------------------------------------------
        Bra
        [a-f]*+
        Once_NC
        gg
        Alt
        hh
        KetRmax
        #
        [a-f]*+
        Brazero
        Once_NC
        gg
        Alt
        hh
        Ket
        #
        [a-f]*
        Brazero
        Once_NC
        gg
        Alt
        hh
        KetRmax
        a#
        [a-f]*+
        Brazero
        Once_NC
        gg
        Alt
        hh
        KetRmax
        h
        Ket
        End
------------------------------------------------------------------

/[a-c]*d/IB
------------------------------------------------------------------
        Bra
        [a-c]*+
        d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: a b c d 
Last code unit = 'd'
Subject length lower bound = 1

/[a-c]+d/IB
------------------------------------------------------------------
        Bra
        [a-c]++
        d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: a b c 
Last code unit = 'd'
Subject length lower bound = 2

/[a-c]?d/IB
------------------------------------------------------------------
        Bra
        [a-c]?+
        d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: a b c d 
Last code unit = 'd'
Subject length lower bound = 1

/[a-c]{4,6}d/IB
------------------------------------------------------------------
        Bra
        [a-c]{4,6}+
        d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: a b c 
Last code unit = 'd'
Subject length lower bound = 5

/[a-c]{0,6}d/IB
------------------------------------------------------------------
        Bra
        [a-c]{0,6}+
        d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: a b c d 
Last code unit = 'd'
Subject length lower bound = 1

# End of special auto-possessive tests 

/^A\o{1239}B/
Failed: error 164 at offset 8: non-octal character in \o{} (closing brace missing?)
    A\123B

/^A\oB/
Failed: error 155 at offset 3: missing opening brace after \o
    
/^A\x{zz}B/
Failed: error 167 at offset 5: non-hex character in \x{} (closing brace missing?)

/^A\x{12Z/
Failed: error 167 at offset 7: non-hex character in \x{} (closing brace missing?)

/^A\x{/
Failed: error 167 at offset 5: non-hex character in \x{} (closing brace missing?)

/[ab]++/B,no_auto_possess
------------------------------------------------------------------
        Bra
        [ab]++
        Ket
        End
------------------------------------------------------------------

/[^ab]*+/B,no_auto_possess
------------------------------------------------------------------
        Bra
        [\x00-`c-\xff] (neg)*+
        Ket
        End
------------------------------------------------------------------

/a{4}+/B,no_auto_possess
------------------------------------------------------------------
        Bra
        a{4}
        Ket
        End
------------------------------------------------------------------

/a{4}+/Bi,no_auto_possess
------------------------------------------------------------------
        Bra
     /i a{4}
        Ket
        End
------------------------------------------------------------------

/[a-[:digit:]]+/
Failed: error 150 at offset 3: invalid range in character class

/[A-[:digit:]]+/
Failed: error 150 at offset 3: invalid range in character class

/[a-[.xxx.]]+/
Failed: error 150 at offset 3: invalid range in character class

/[a-[=xxx=]]+/
Failed: error 150 at offset 3: invalid range in character class

/[a-[!xxx!]]+/
Failed: error 108 at offset 3: range out of order in character class

/[A-[!xxx!]]+/
    A]]]
 0: A]]]

/[a-\d]+/
Failed: error 150 at offset 4: invalid range in character class

/(?<0abc>xx)/
Failed: error 144 at offset 3: group name must start with a non-digit

/(?&1abc)xx(?<1abc>y)/
Failed: error 144 at offset 3: group name must start with a non-digit

/(?<ab-cd>xx)/
Failed: error 142 at offset 5: syntax error in subpattern name (missing terminator)

/(?'0abc'xx)/
Failed: error 144 at offset 3: group name must start with a non-digit

/(?P<0abc>xx)/
Failed: error 144 at offset 4: group name must start with a non-digit

/\k<5ghj>/
Failed: error 144 at offset 3: group name must start with a non-digit

/\k'5ghj'/
Failed: error 144 at offset 3: group name must start with a non-digit

/\k{2fgh}/
Failed: error 144 at offset 3: group name must start with a non-digit

/(?P=8yuki)/
Failed: error 144 at offset 4: group name must start with a non-digit

/\g{4df}/
Failed: error 144 at offset 3: group name must start with a non-digit

/(?&1abc)xx(?<1abc>y)/
Failed: error 144 at offset 3: group name must start with a non-digit

/(?P>1abc)xx(?<1abc>y)/
Failed: error 144 at offset 4: group name must start with a non-digit

/\g'3gh'/
Failed: error 157 at offset 7: \g is not followed by a braced, angle-bracketed, or quoted name/number or by a plain number

/\g<5fg>/
Failed: error 157 at offset 7: \g is not followed by a braced, angle-bracketed, or quoted name/number or by a plain number

/(?(<4gh>)abc)/
Failed: error 144 at offset 4: group name must start with a non-digit

/(?('4gh')abc)/
Failed: error 144 at offset 4: group name must start with a non-digit

/(?(4gh)abc)/
Failed: error 126 at offset 4: malformed number or name after (?(

/(?(R&6yh)abc)/
Failed: error 144 at offset 5: group name must start with a non-digit

/(((a\2)|(a*)\g<-1>))*a?/B
------------------------------------------------------------------
        Bra
        Brazero
        SCBra 1
        Once
        CBra 2
        CBra 3
        a
        \2
        Ket
        Alt
        CBra 4
        a*
        Ket
        Recurse
        Ket
        Ket
        KetRmax
        a?+
        Ket
        End
------------------------------------------------------------------

# Test the ugly "start or end of word" compatibility syntax.

/[[:<:]]red[[:>:]]/B
------------------------------------------------------------------
        Bra
        \b
        Assert
        \w
        Ket
        red
        \b
        AssertB
        Reverse
        \w
        Ket
        Ket
        End
------------------------------------------------------------------
    little red riding hood
 0: red
    a /red/ thing 
 0: red
    red is a colour
 0: red
    put it all on red  
 0: red
    ** Failers
No match
    no reduction
No match
    Alfred Winifred
No match
    
/[a[:<:]] should give error/
Failed: error 130 at offset 4: unknown POSIX class name

/(?=ab\K)/aftertext
    abcd
Start of matched string is beyond its end - displaying from end to start.
 0: ab
 0+ abcd

/abcd/newline=lf,firstline
    xx\nxabcd
No match
    
# Test stack guard external calls.

/(((a)))/stackguard=1
Failed: error 133 at offset 2: parentheses are too deeply nested (stack check)

/(((a)))/stackguard=2
Failed: error 133 at offset 3: parentheses are too deeply nested (stack check)

/(((a)))/stackguard=3

/(((((a)))))/

# End stack guard tests

/^\w+(?>\s*)(?<=\w)/B
------------------------------------------------------------------
        Bra
        ^
        \w+
        Once_NC
        \s*+
        Ket
        AssertB
        Reverse
        \w
        Ket
        Ket
        End
------------------------------------------------------------------

/\othing/
Failed: error 155 at offset 1: missing opening brace after \o

/\o{}/
Failed: error 178 at offset 1: digits missing in \x{} or \o{}

/\o{whatever}/
Failed: error 164 at offset 3: non-octal character in \o{} (closing brace missing?)

/\xthing/

/\x{}/
Failed: error 178 at offset 3: digits missing in \x{} or \o{}

/\x{whatever}/
Failed: error 167 at offset 3: non-hex character in \x{} (closing brace missing?)

/A\8B/
Failed: error 115 at offset 4: reference to non-existent subpattern

/A\9B/
Failed: error 115 at offset 4: reference to non-existent subpattern

# This one is here because Perl fails to match "12" for this pattern when the $ 
# is present.
    
/^(?(?=abc)\w{3}:|\d\d)$/
    abc:
 0: abc:
    12
 0: 12
    *** Failers
No match
    123
No match
    xyz    
No match

# Perl gets this one wrong, giving "a" as the after text for ca and failing to 
# match for cd.

/(?(?=ab)ab)/aftertext
    abxxx
 0: ab
 0+ xxx
    ca
 0: 
 0+ ca
    cd 
 0: 
 0+ cd
    
# This should test both paths for processing OP_RECURSE. 

/(?(R)a+|(?R)b)/
    aaaabcde
 0: aaaab
    aaaabcde\=ovector=100
 0: aaaab

/abc(?=xyz)/allusedtext
    abcxyzpqr
 0: abcxyz
       >>>
    abcxyzpqr\=aftertext
 0: abcxyz
       >>>
 0+ xyzpqr
    
/(?<=pqr)abc(?=xyz)/allusedtext
    xyzpqrabcxyzpqr
 0: pqrabcxyz
    <<<   >>>
    xyzpqrabcxyzpqr\=aftertext
 0: pqrabcxyz
    <<<   >>>
 0+ xyzpqr
    
/a\b/
    a.\=allusedtext
 0: a.
     >
    a\=allusedtext  
 0: a

/abc\Kxyz/
    abcxyz\=allusedtext
 0: abcxyz
    <<<   

/abc(?=xyz(*ACCEPT))/
    abcxyz\=allusedtext
 0: abcxyz
       >>>

/abc(?=abcde)(?=ab)/allusedtext
    abcabcdefg
 0: abcabcde
       >>>>>

/a*?b*?/
    ab
 0: 

/(*NOTEMPTY)a*?b*?/
    ab
 0: a
    ba
 0: b
    cb  
 0: b

/(*NOTEMPTY_ATSTART)a*?b*?/aftertext
    ab
 0: a
 0+ b
    cdab 
 0: 
 0+ dab

/(?(VERSION>=10.0)yes|no)/I
Capturing subpattern count = 0
Subject length lower bound = 2
    yesno
 0: yes
    
/(?(VERSION=8)yes){3}/BI,aftertext
------------------------------------------------------------------
        Bra
        Cond
        Cond false
        yes
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    yesno
 0: 
 0+ yesno

/(?(VERSION=8)yes|no){3}/I
Capturing subpattern count = 0
Subject length lower bound = 6
    yesnononoyes
 0: nonono
    ** Failers
No match
    yesno   
No match

/(?:(?<VERSION>abc)|xyz)(?(VERSION)yes|no)/I
Capturing subpattern count = 1
Named capturing subpatterns:
  VERSION   1
Starting code units: a x 
Subject length lower bound = 5
    abcyes
 0: abcyes
 1: abc
    xyzno
 0: xyzno
    ** Failers
No match
    abcno
No match
    xyzyes    
No match

/(?(VERSION<10)yes|no)/
Failed: error 179 at offset 10: syntax error in (?(VERSION condition

/(?(VERSION>10)yes|no)/
Failed: error 179 at offset 11: syntax error in (?(VERSION condition

/(?(VERSION>=10.0.0)yes|no)/
Failed: error 179 at offset 16: syntax error in (?(VERSION condition

# End of testinput2