Documentation update.
This commit is contained in:
Philip.Hazel
parent
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@ -1085,12 +1085,19 @@ Resetting the match start
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</b><br>
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<P>
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The escape sequence \K causes any previously matched characters not to be
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included in the final matched sequence. For example, the pattern:
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included in the final matched sequence that is returned. For example, the
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pattern:
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<pre>
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foo\Kbar
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</pre>
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matches "foobar", but reports that it has matched "bar". This feature is
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similar to a lookbehind assertion
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matches "foobar", but reports that it has matched "bar". \K does not interact
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with anchoring in any way. The pattern:
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<pre>
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^foo\Kbar
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</pre>
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matches only when the subject begins with "foobar" (in single line mode),
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though it again reports the matched string as "bar". This feature is similar to
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a lookbehind assertion
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<a href="#lookbehind">(described below).</a>
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However, in this case, the part of the subject before the real match does not
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have to be of fixed length, as lookbehind assertions do. The use of \K does
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@ -1107,7 +1114,8 @@ Perl documents that the use of \K within assertions is "not well defined". In
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PCRE2, \K is acted upon when it occurs inside positive assertions, but is
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ignored in negative assertions. Note that when a pattern such as (?=ab\K)
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matches, the reported start of the match can be greater than the end of the
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match.
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match. Using \K in a lookbehind assertion at the start of a pattern can also
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lead to odd effects.
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<a name="smallassertions"></a></P>
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<br><b>
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Simple assertions
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@ -1158,18 +1166,18 @@ end.
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</P>
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<P>
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The \G assertion is true only when the current matching position is at the
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start point of the match, as specified by the <i>startoffset</i> argument of
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<b>pcre2_match()</b>. It differs from \A when the value of <i>startoffset</i> is
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non-zero. By calling <b>pcre2_match()</b> multiple times with appropriate
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arguments, you can mimic Perl's /g option, and it is in this kind of
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implementation where \G can be useful.
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start point of the matching process, as specified by the <i>startoffset</i>
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argument of <b>pcre2_match()</b>. It differs from \A when the value of
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<i>startoffset</i> is non-zero. By calling <b>pcre2_match()</b> multiple times
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with appropriate arguments, you can mimic Perl's /g option, and it is in this
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kind of implementation where \G can be useful.
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</P>
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<P>
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Note, however, that PCRE2's interpretation of \G, as the start of the current
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match, is subtly different from Perl's, which defines it as the end of the
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previous match. In Perl, these can be different when the previously matched
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string was empty. Because PCRE2 does just one match at a time, it cannot
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reproduce this behaviour.
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Note, however, that PCRE2's implementation of \G, being true at the starting
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character of the matching process, is subtly different from Perl's, which
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defines it as true at the end of the previous match. In Perl, these can be
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different when the previously matched string was empty. Because PCRE2 does just
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one match at a time, it cannot reproduce this behaviour.
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</P>
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<P>
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If all the alternatives of a pattern begin with \G, the expression is anchored
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@ -3476,7 +3484,7 @@ Cambridge, England.
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</P>
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<br><a name="SEC30" href="#TOC1">REVISION</a><br>
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<P>
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Last updated: 25 April 2018
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Last updated: 28 June 2018
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<br>
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Copyright © 1997-2018 University of Cambridge.
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<br>
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@ -23,7 +23,7 @@ please consult the man page, in case the conversion went wrong.
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<li><a name="TOC8" href="#SEC8">CHARACTER CLASSES</a>
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<li><a name="TOC9" href="#SEC9">QUANTIFIERS</a>
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<li><a name="TOC10" href="#SEC10">ANCHORS AND SIMPLE ASSERTIONS</a>
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<li><a name="TOC11" href="#SEC11">MATCH POINT RESET</a>
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<li><a name="TOC11" href="#SEC11">REPORTED MATCH POINT SETTING</a>
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<li><a name="TOC12" href="#SEC12">ALTERNATION</a>
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<li><a name="TOC13" href="#SEC13">CAPTURING</a>
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<li><a name="TOC14" href="#SEC14">ATOMIC GROUPS</a>
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@ -387,10 +387,10 @@ but some of them use Unicode properties if PCRE2_UCP is set. You can use
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\G first matching position in subject
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</PRE>
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</P>
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<br><a name="SEC11" href="#TOC1">MATCH POINT RESET</a><br>
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<br><a name="SEC11" href="#TOC1">REPORTED MATCH POINT SETTING</a><br>
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<P>
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<pre>
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\K reset start of match
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\K set reported start of match
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</pre>
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\K is honoured in positive assertions, but ignored in negative ones.
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</P>
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@ -600,9 +600,9 @@ Cambridge, England.
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</P>
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<br><a name="SEC27" href="#TOC1">REVISION</a><br>
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<P>
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Last updated: 17 June 2017
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Last updated: 28 June 2018
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<br>
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Copyright © 1997-2017 University of Cambridge.
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Copyright © 1997-2018 University of Cambridge.
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<br>
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<p>
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Return to the <a href="index.html">PCRE2 index page</a>.
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@ -6665,16 +6665,23 @@ BACKSLASH
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Resetting the match start
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The escape sequence \K causes any previously matched characters not to
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be included in the final matched sequence. For example, the pattern:
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be included in the final matched sequence that is returned. For exam-
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ple, the pattern:
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foo\Kbar
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matches "foobar", but reports that it has matched "bar". This feature
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is similar to a lookbehind assertion (described below). However, in
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this case, the part of the subject before the real match does not have
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to be of fixed length, as lookbehind assertions do. The use of \K does
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not interfere with the setting of captured substrings. For example,
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when the pattern
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matches "foobar", but reports that it has matched "bar". \K does not
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interact with anchoring in any way. The pattern:
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^foo\Kbar
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matches only when the subject begins with "foobar" (in single line
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mode), though it again reports the matched string as "bar". This fea-
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ture is similar to a lookbehind assertion (described below). However,
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in this case, the part of the subject before the real match does not
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have to be of fixed length, as lookbehind assertions do. The use of \K
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does not interfere with the setting of captured substrings. For exam-
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ple, when the pattern
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(foo)\Kbar
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@ -6684,7 +6691,8 @@ BACKSLASH
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defined". In PCRE2, \K is acted upon when it occurs inside positive
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assertions, but is ignored in negative assertions. Note that when a
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pattern such as (?=ab\K) matches, the reported start of the match can
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be greater than the end of the match.
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be greater than the end of the match. Using \K in a lookbehind asser-
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tion at the start of a pattern can also lead to odd effects.
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Simple assertions
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@ -6729,17 +6737,18 @@ BACKSLASH
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as well as at the very end, whereas \z matches only at the end.
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The \G assertion is true only when the current matching position is at
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the start point of the match, as specified by the startoffset argument
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of pcre2_match(). It differs from \A when the value of startoffset is
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non-zero. By calling pcre2_match() multiple times with appropriate
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arguments, you can mimic Perl's /g option, and it is in this kind of
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implementation where \G can be useful.
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the start point of the matching process, as specified by the startoff-
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set argument of pcre2_match(). It differs from \A when the value of
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startoffset is non-zero. By calling pcre2_match() multiple times with
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appropriate arguments, you can mimic Perl's /g option, and it is in
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this kind of implementation where \G can be useful.
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Note, however, that PCRE2's interpretation of \G, as the start of the
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current match, is subtly different from Perl's, which defines it as the
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end of the previous match. In Perl, these can be different when the
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previously matched string was empty. Because PCRE2 does just one match
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at a time, it cannot reproduce this behaviour.
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Note, however, that PCRE2's implementation of \G, being true at the
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starting character of the matching process, is subtly different from
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Perl's, which defines it as true at the end of the previous match. In
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Perl, these can be different when the previously matched string was
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empty. Because PCRE2 does just one match at a time, it cannot reproduce
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this behaviour.
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If all the alternatives of a pattern begin with \G, the expression is
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anchored to the starting match position, and the "anchored" flag is set
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@ -8921,7 +8930,7 @@ AUTHOR
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REVISION
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Last updated: 25 April 2018
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Last updated: 28 June 2018
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Copyright (c) 1997-2018 University of Cambridge.
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------------------------------------------------------------------------------
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@ -9982,9 +9991,9 @@ ANCHORS AND SIMPLE ASSERTIONS
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\G first matching position in subject
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MATCH POINT RESET
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REPORTED MATCH POINT SETTING
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\K reset start of match
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\K set reported start of match
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\K is honoured in positive assertions, but ignored in negative ones.
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@ -10190,8 +10199,8 @@ AUTHOR
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REVISION
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Last updated: 17 June 2017
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Copyright (c) 1997-2017 University of Cambridge.
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Last updated: 28 June 2018
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Copyright (c) 1997-2018 University of Cambridge.
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------------------------------------------------------------------------------
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@ -1,4 +1,4 @@
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.TH PCRE2PATTERN 3 "25 April 2018" "PCRE2 10.32"
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.TH PCRE2PATTERN 3 "28 June 2018" "PCRE2 10.32"
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.SH NAME
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PCRE2 - Perl-compatible regular expressions (revised API)
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.SH "PCRE2 REGULAR EXPRESSION DETAILS"
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@ -1073,12 +1073,19 @@ sequences but the characters that they represent.)
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.rs
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.sp
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The escape sequence \eK causes any previously matched characters not to be
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included in the final matched sequence. For example, the pattern:
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included in the final matched sequence that is returned. For example, the
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pattern:
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.sp
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foo\eKbar
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.sp
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matches "foobar", but reports that it has matched "bar". This feature is
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similar to a lookbehind assertion
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matches "foobar", but reports that it has matched "bar". \eK does not interact
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with anchoring in any way. The pattern:
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.sp
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^foo\eKbar
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.sp
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matches only when the subject begins with "foobar" (in single line mode),
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though it again reports the matched string as "bar". This feature is similar to
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a lookbehind assertion
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.\" HTML <a href="#lookbehind">
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.\" </a>
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(described below).
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@ -1100,7 +1107,8 @@ Perl documents that the use of \eK within assertions is "not well defined". In
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PCRE2, \eK is acted upon when it occurs inside positive assertions, but is
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ignored in negative assertions. Note that when a pattern such as (?=ab\eK)
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matches, the reported start of the match can be greater than the end of the
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match.
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match. Using \eK in a lookbehind assertion at the start of a pattern can also
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lead to odd effects.
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.
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.
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.\" HTML <a name="smallassertions"></a>
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@ -1152,17 +1160,17 @@ end of the string as well as at the very end, whereas \ez matches only at the
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end.
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.P
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The \eG assertion is true only when the current matching position is at the
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start point of the match, as specified by the \fIstartoffset\fP argument of
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\fBpcre2_match()\fP. It differs from \eA when the value of \fIstartoffset\fP is
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non-zero. By calling \fBpcre2_match()\fP multiple times with appropriate
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arguments, you can mimic Perl's /g option, and it is in this kind of
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implementation where \eG can be useful.
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start point of the matching process, as specified by the \fIstartoffset\fP
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argument of \fBpcre2_match()\fP. It differs from \eA when the value of
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\fIstartoffset\fP is non-zero. By calling \fBpcre2_match()\fP multiple times
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with appropriate arguments, you can mimic Perl's /g option, and it is in this
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kind of implementation where \eG can be useful.
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.P
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Note, however, that PCRE2's interpretation of \eG, as the start of the current
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match, is subtly different from Perl's, which defines it as the end of the
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previous match. In Perl, these can be different when the previously matched
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string was empty. Because PCRE2 does just one match at a time, it cannot
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reproduce this behaviour.
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Note, however, that PCRE2's implementation of \eG, being true at the starting
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character of the matching process, is subtly different from Perl's, which
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defines it as true at the end of the previous match. In Perl, these can be
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different when the previously matched string was empty. Because PCRE2 does just
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one match at a time, it cannot reproduce this behaviour.
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.P
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If all the alternatives of a pattern begin with \eG, the expression is anchored
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to the starting match position, and the "anchored" flag is set in the compiled
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@ -3503,6 +3511,6 @@ Cambridge, England.
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.rs
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.sp
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.nf
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Last updated: 25 April 2018
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Last updated: 28 June 2018
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Copyright (c) 1997-2018 University of Cambridge.
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.fi
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@ -1,4 +1,4 @@
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.TH PCRE2SYNTAX 3 "17 June 2017" "PCRE2 10.30"
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.TH PCRE2SYNTAX 3 "28 June 2018" "PCRE2 10.32"
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.SH NAME
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PCRE2 - Perl-compatible regular expressions (revised API)
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.SH "PCRE2 REGULAR EXPRESSION SYNTAX SUMMARY"
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@ -361,10 +361,10 @@ but some of them use Unicode properties if PCRE2_UCP is set. You can use
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\eG first matching position in subject
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.
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.
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.SH "MATCH POINT RESET"
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.SH "REPORTED MATCH POINT SETTING"
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.rs
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.sp
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\eK reset start of match
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\eK set reported start of match
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.sp
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\eK is honoured in positive assertions, but ignored in negative ones.
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.
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@ -589,6 +589,6 @@ Cambridge, England.
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.rs
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.sp
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.nf
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Last updated: 17 June 2017
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Copyright (c) 1997-2017 University of Cambridge.
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Last updated: 28 June 2018
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Copyright (c) 1997-2018 University of Cambridge.
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.fi
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