Bug #79028 [Csd->Nab]: Several same-name subpatterns in distinct piped alternatives should be allowed

Edit report at https://bugs.php.net/bug.php?id=79028&edit=1 ID: 79028 Updated by: cmb@php.net Reported by: php4fan at gmail dot com Summary: Several same-name subpatterns in distinct piped alternatives should be allowed -Status: Closed +Status: Not a bug Type: Bug Package: *Regular Expressions PHP Version: 7.2.26 Block user comment: N Private report: N Previous Comments: ------------------------------------------------------------------------ [2019-12-24 17:36:50] php4fan at gmail dot com Ok, I see, "(?J)" modifies the behavior to accomplish what I asked for. So, not a bug. Sorry about the noise. ------------------------------------------------------------------------ [2019-12-24 17:18:05] php4fan at gmail dot com Description: ------------ see below test script and expected and observed behavior below. Maybe this an issue at the level of regular expressions specifications. As I only use them in PHP, I don't know, so I report it here. Also, it's so evidently flawed that maybe PHP could implement them correctly anyway while waiting for the specs to be fixed; not sure about that. Test script: --------------- <?php $content = <<<'HERE' First match: foo::"XYZ" Second match: bar--<XYZ> HERE; $content=preg_replace_callback('#foo::"(?<sub>[^"]*)"|bar--<(?<sub>[^>]*)>#', 'testReplace', $content); function testReplace($match) { print_r($match); return 'XXX'; } Expected result: ---------------- Array ( [0] => foo::"XYZ" [sub] => XYZ [1] => XYZ ) Array ( [0] => bar--<XYZ> [1] => [sub] => XYZ [2] => XYZ ) Actual result: -------------- Warning: preg_replace_callback(): Compilation failed: two named subpatterns have the same name Because the subgroups with the same name appear on two sides of a "|", there should be no conflict. At most one of the piped patterns (i.e. either side of the "|") can match, they are mutually exclusive, so there is no ambiguity possible and it should be a problem that a subgroup appear in both of them with the same name, as it can only be assigned once anyway. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=79028&edit=1