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revision 1193 by ph10, Sat Jan 21 16:37:17 2012 UTC revision 1194 by ph10, Wed Oct 31 17:42:29 2012 UTC
# Line 26  man page, in case the conversion went wr Line 26  man page, in case the conversion went wr
26  <P>  <P>
27  This document describes the two different algorithms that are available in PCRE  This document describes the two different algorithms that are available in PCRE
28  for matching a compiled regular expression against a given subject string. The  for matching a compiled regular expression against a given subject string. The
29  "standard" algorithm is the one provided by the <b>pcre_exec()</b> and  "standard" algorithm is the one provided by the <b>pcre_exec()</b>,
30  <b>pcre16_exec()</b> functions. These work in the same was as Perl's matching  <b>pcre16_exec()</b> and <b>pcre32_exec()</b> functions. These work in the same
31  function, and provide a Perl-compatible matching operation. The just-in-time  as as Perl's matching function, and provide a Perl-compatible matching operation.
32  (JIT) optimization that is described in the  The just-in-time (JIT) optimization that is described in the
33  <a href="pcrejit.html"><b>pcrejit</b></a>  <a href="pcrejit.html"><b>pcrejit</b></a>
34  documentation is compatible with these functions.  documentation is compatible with these functions.
35  </P>  </P>
36  <P>  <P>
37  An alternative algorithm is provided by the <b>pcre_dfa_exec()</b> and  An alternative algorithm is provided by the <b>pcre_dfa_exec()</b>,
38  <b>pcre16_dfa_exec()</b> functions; they operate in a different way, and are not  <b>pcre16_dfa_exec()</b> and <b>pcre32_dfa_exec()</b> functions; they operate in
39  Perl-compatible. This alternative has advantages and disadvantages compared  a different way, and are not Perl-compatible. This alternative has advantages
40  with the standard algorithm, and these are described below.  and disadvantages compared with the standard algorithm, and these are described
41    below.
42  </P>  </P>
43  <P>  <P>
44  When there is only one possible way in which a given subject string can match a  When there is only one possible way in which a given subject string can match a
# Line 167  always 1, and the value of the <i>captur Line 168  always 1, and the value of the <i>captur
168  </P>  </P>
169  <P>  <P>
170  7. The \C escape sequence, which (in the standard algorithm) always matches a  7. The \C escape sequence, which (in the standard algorithm) always matches a
171  single data unit, even in UTF-8 or UTF-16 modes, is not supported in these  single data unit, even in UTF-8, UTF-16 or UTF-32 modes, is not supported in
172  modes, because the alternative algorithm moves through the subject string one  these modes, because the alternative algorithm moves through the subject string
173  character (not data unit) at a time, for all active paths through the tree.  one character (not data unit) at a time, for all active paths through the tree.
174  </P>  </P>
175  <P>  <P>
176  8. Except for (*FAIL), the backtracking control verbs such as (*PRUNE) are not  8. Except for (*FAIL), the backtracking control verbs such as (*PRUNE) are not

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