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Diffstat (limited to 'dist2/doc/html/pcre2matching.html')
| -rw-r--r-- | dist2/doc/html/pcre2matching.html | 24 |
1 files changed, 10 insertions, 14 deletions
diff --git a/dist2/doc/html/pcre2matching.html b/dist2/doc/html/pcre2matching.html index 3e32cb57..602f3b26 100644 --- a/dist2/doc/html/pcre2matching.html +++ b/dist2/doc/html/pcre2matching.html @@ -134,8 +134,7 @@ do want multiple matches in such cases, either use an ungreedy repeat </P> <P> There are a number of features of PCRE2 regular expressions that are not -supported or behave differently in the alternative matching function. Those -that are not supported cause an error if encountered. +supported by the alternative matching algorithm. They are as follows: </P> <P> 1. Because the algorithm finds all possible matches, the greedy or ungreedy @@ -160,32 +159,29 @@ do this. This means that no captured substrings are available. </P> <P> 3. Because no substrings are captured, backreferences within the pattern are -not supported. +not supported, and cause errors if encountered. </P> <P> 4. For the same reason, conditional expressions that use a backreference as the condition or test for a specific group recursion are not supported. </P> <P> -5. Again for the same reason, script runs are not supported. -</P> -<P> -6. Because many paths through the tree may be active, the \K escape sequence, +5. Because many paths through the tree may be active, the \K escape sequence, which resets the start of the match when encountered (but may be on some paths -and not on others), is not supported. +and not on others), is not supported. It causes an error if encountered. </P> <P> -7. Callouts are supported, but the value of the <i>capture_top</i> field is +6. Callouts are supported, but the value of the <i>capture_top</i> field is always 1, and the value of the <i>capture_last</i> field is always 0. </P> <P> -8. 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 single code unit, even in a UTF mode, is not supported in these modes, because the alternative algorithm moves through the subject string one character (not code unit) at a time, for all active paths through the tree. </P> <P> -9. 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 supported. (*FAIL) is supported, and behaves like a failing negative assertion. </P> <br><a name="SEC5" href="#TOC1">ADVANTAGES OF THE ALTERNATIVE ALGORITHM</a><br> @@ -219,7 +215,7 @@ because it has to search for all possible matches, but is also because it is less susceptible to optimization. </P> <P> -2. Capturing parentheses, backreferences, and script runs are not supported. +2. Capturing parentheses and backreferences are not supported. </P> <P> 3. Although atomic groups are supported, their use does not provide the @@ -236,9 +232,9 @@ Cambridge, England. </P> <br><a name="SEC8" href="#TOC1">REVISION</a><br> <P> -Last updated: 10 October 2018 +Last updated: 29 September 2014 <br> -Copyright © 1997-2018 University of Cambridge. +Copyright © 1997-2014 University of Cambridge. <br> <p> Return to the <a href="index.html">PCRE2 index page</a>. |