Am 13.01.23 um 09:28 schrieb Ævar Arnfjörð Bjarmason: > > There's a couple of ways out of this that I don't see in this thread: > > - Declare it not a problem: We have -G, -E and -P to map to BRE, ERE and > PCRE. One view is to say the first two must match POSIX, another is > tha whatever the platform thinks they should do is how they should > act. I like that and it was my first reaction -- alternation is a non-standard extension to BREs. But we supported it explicitly since 3632cfc248 (Use compatibility regex library for OSX/Darwin, 2008-09-07), so not having it anymore is a regression that we should fix, I think. > Of course that makes git regex invocations "unportable", but it might > be acceptable. People can always use PCRE if they want "portability". > > - Just mandate PCRE for Mac OS, then map -E to -P. We could do this with > the pcre2convert() API and PCRE2_CONVERT_POSIX_EXTENDED flag, > i.e. PCRE's own "translate this to ERE". > > But Perl/PCRE syntax is already a superset of ERE syntax, minus things > like (*VERB), (?: etc., which people are unlikely to write without > intending to get the PCRE semantics. PCRE2_CONVERT_POSIX_EXTENDED is a flag for pcre2_pattern_convert(), which allows converting an ERE into a PCRE2 regex (https://pcre.org/current/doc/html/pcre2convert.html). So this feature allows using PCRE for every kind of regexes, right? There may be feature differences for EREs between libc on macOS, glibc and/or GAWK, but I'm not aware of any complaints so far. So I currently don't see the need for that. René
