note 58559 added to reference.pcre.pattern.syntax

<quote> 9. Another as yet unresolved discrepancy is that in Perl 5.005_02 the pattern /^(a)?(?(1)a|b)+$/ matches the string "a", whereas in PCRE it does not. However, in both Perl and PCRE /^(a)?a/ matched against "a" leaves $1 unset. </quote> The last sentence does not indicate a bug. If the string "a" should match against the regular expression /^(a)?a/, the last "a" in the regex must be matched by any literal "a" in the string. The rest of the string is "", which obviously does not match the first /^(a)/. ---- Manual Page -- http://www.php.net/manual/en/reference.pcre.pattern.syntax.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+58559 Delete: added to the manual -- http://master.php.net/manage/user-notes.php?action=delete+58559&report=yes&reason=added+to+the+manual Delete: bad code -- http://master.php.net/manage/user-notes.php?action=delete+58559&report=yes&reason=bad+code Delete: spam -- http://master.php.net/manage/user-notes.php?action=delete+58559&report=yes&reason=spam Delete: useless -- http://master.php.net/manage/user-notes.php?action=delete+58559&report=yes&reason=useless Delete: non-english -- http://master.php.net/manage/user-notes.php?action=delete+58559&report=yes&reason=non-english Delete: already in docs -- http://master.php.net/manage/user-notes.php?action=delete+58559&report=yes&reason=already+in+docs Delete: other reasons -- http://master.php.net/manage/user-notes.php?action=delete+58559&report=yes Reject -- http://master.php.net/manage/user-notes.php?action=reject+58559&report=yes Search -- http://master.php.net/manage/user-notes.php