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Documentation and test update.

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Philip.Hazel 2019-07-28 15:32:11 +00:00
parent 24c62fc0d0
commit fe2df37c9f
5 changed files with 88 additions and 19 deletions
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21
doc/html/pcre2pattern.html
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@ -3758,11 +3758,20 @@ retained in both cases.
</P>
<P>
The remaining verbs act only when a later failure causes a backtrack to
reach them. This means that their effect is confined to the assertion,
because lookaround assertions are atomic. A backtrack that occurs after an
assertion is complete does not jump back into the assertion. Note in particular
that a (*MARK) name that is set in an assertion is not "seen" by an instance of
(*SKIP:NAME) latter in the pattern.
reach them. This means that, for the Perl-compatible assertions, their effect
is confined to the assertion, because Perl lookaround assertions are atomic. A
backtrack that occurs after such an assertion is complete does not jump back
into the assertion. Note in particular that a (*MARK) name that is set in an
assertion is not "seen" by an instance of (*SKIP:NAME) later in the pattern.
</P>
<P>
PCRE2 now supports non-atomic positive assertions, as described in the section
entitled
<a href="#nonatomicassertions"> "Non-atomic assertions"</a>
above. These assertions must be standalone (not used as conditions). They are
not Perl-compatible. For these assertions, a later backtrack does jump back
into the assertion, and therefore verbs such as (*COMMIT) can be triggered by
backtracks from later in the pattern.
</P>
<P>
The effect of (*THEN) is not allowed to escape beyond an assertion. If there
@ -3820,7 +3829,7 @@ Cambridge, England.
</P>
<br><a name="SEC32" href="#TOC1">REVISION</a><br>
<P>
Last updated: 13 July 2019
Last updated: 28 July 2019
<br>
Copyright &copy; 1997-2019 University of Cambridge.
<br>

20
doc/pcre2.txt
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@ -9439,11 +9439,19 @@ BACKTRACKING CONTROL
substrings are retained in both cases.
The remaining verbs act only when a later failure causes a backtrack to
reach them. This means that their effect is confined to the assertion,
because lookaround assertions are atomic. A backtrack that occurs after
an assertion is complete does not jump back into the assertion. Note in
particular that a (*MARK) name that is set in an assertion is not
"seen" by an instance of (*SKIP:NAME) latter in the pattern.
reach them. This means that, for the Perl-compatible assertions, their
effect is confined to the assertion, because Perl lookaround assertions
are atomic. A backtrack that occurs after such an assertion is complete
does not jump back into the assertion. Note in particular that a
(*MARK) name that is set in an assertion is not "seen" by an instance
of (*SKIP:NAME) later in the pattern.
PCRE2 now supports non-atomic positive assertions, as described in the
section entitled "Non-atomic assertions" above. These assertions must
be standalone (not used as conditions). They are not Perl-compatible.
For these assertions, a later backtrack does jump back into the asser-
tion, and therefore verbs such as (*COMMIT) can be triggered by back-
tracks from later in the pattern.
The effect of (*THEN) is not allowed to escape beyond an assertion. If
there are no more branches to try, (*THEN) causes a positive assertion
@ -9494,7 +9502,7 @@ AUTHOR
REVISION
Last updated: 13 July 2019
Last updated: 28 July 2019
Copyright (c) 1997-2019 University of Cambridge.
------------------------------------------------------------------------------

25
doc/pcre2pattern.3
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@ -1,4 +1,4 @@
.TH PCRE2PATTERN 3 "13 July 2019" "PCRE2 10.34"
.TH PCRE2PATTERN 3 "28 July 2019" "PCRE2 10.34"
.SH NAME
PCRE2 - Perl-compatible regular expressions (revised API)
.SH "PCRE2 REGULAR EXPRESSION DETAILS"
@ -3796,11 +3796,22 @@ a positive assertion and false for a negative one; captured substrings are
retained in both cases.
.P
The remaining verbs act only when a later failure causes a backtrack to
reach them. This means that their effect is confined to the assertion,
because lookaround assertions are atomic. A backtrack that occurs after an
assertion is complete does not jump back into the assertion. Note in particular
that a (*MARK) name that is set in an assertion is not "seen" by an instance of
(*SKIP:NAME) latter in the pattern.
reach them. This means that, for the Perl-compatible assertions, their effect
is confined to the assertion, because Perl lookaround assertions are atomic. A
backtrack that occurs after such an assertion is complete does not jump back
into the assertion. Note in particular that a (*MARK) name that is set in an
assertion is not "seen" by an instance of (*SKIP:NAME) later in the pattern.
.P
PCRE2 now supports non-atomic positive assertions, as described in the section
entitled
.\" HTML <a href="#nonatomicassertions">
.\" </a>
"Non-atomic assertions"
.\"
above. These assertions must be standalone (not used as conditions). They are
not Perl-compatible. For these assertions, a later backtrack does jump back
into the assertion, and therefore verbs such as (*COMMIT) can be triggered by
backtracks from later in the pattern.
.P
The effect of (*THEN) is not allowed to escape beyond an assertion. If there
are no more branches to try, (*THEN) causes a positive assertion to be false,
@ -3859,6 +3870,6 @@ Cambridge, England.
.rs
.sp
.nf
Last updated: 13 July 2019
Last updated: 28 July 2019
Copyright (c) 1997-2019 University of Cambridge.
.fi

15
testdata/testinput2 vendored
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@ -5688,6 +5688,21 @@ a)"xI
/(*napla:abc|abd)/I
/(*napla:a|(.)(*ACCEPT)zz)\1../
abcd
/(*napla:a(*ACCEPT)zz|(.))\1../
abcd
/(*napla:a|(*COMMIT)(.))\1\1/
aabc
\= Expect no match
abbc
/(*napla:a|(.))\1\1/
aabc
abbc
# ----
# Expect error (recursion => not fixed length)

26
testdata/testoutput2 vendored
View File

@ -17185,6 +17185,32 @@ May match empty string
First code unit = 'a'
Subject length lower bound = 1
/(*napla:a|(.)(*ACCEPT)zz)\1../
abcd
0: abc
1: a
/(*napla:a(*ACCEPT)zz|(.))\1../
abcd
0: bcd
1: b
/(*napla:a|(*COMMIT)(.))\1\1/
aabc
0: aa
1: a
\= Expect no match
abbc
No match
/(*napla:a|(.))\1\1/
aabc
0: aa
1: a
abbc
0: bb
1: b
# ----
# Expect error (recursion => not fixed length)