Ævar Arnfjörð Bjarmason <ava...@gmail.com> writes: > On Mon, May 15, 2017 at 6:57 AM, Junio C Hamano <gits...@pobox.com> wrote: >> Ævar Arnfjörð Bjarmason <ava...@gmail.com> writes: >>> + if test_have_prereq PCRE >>> + then >>> + # Only PCRE would match [\d]\| with only >>> + # "(1|2)" due to [\d]. POSIX basic would match >>> + # both it and "1", and POSIX extended would >>> + # match neither. >> >> OK. BRE would match because the other side of "\|" is empty to >> match anything? > > Yes. I'll clarify this. It's not just a POSIX basic feature. The same > is true of extended and perl. E.g.:
Yes, but "\|" won't be taken as alternative in ERE or PCRE, and that is why "[\d]\|" would match everything with BRE (as opposed to others---PCRE matches "(1|2)" not because "\|" is an alternative but because the pattern looks for a digit followed by a literal vert-bar, and ERE does not match any because there is no 'd' followed by a literal vert-bar). I was mostly reacting to "BRE would match both it and '1'", which singled out "1" as if "1" is special and gives a false impression that it wouldn't have matched if it were "7". > > git grep [-E|-P] 'foo|bar' > > Both match the same as: > > git grep [-E|-P] '(foo|bar)' > >>> + git -c grep.patternType=perl log --pretty=tformat:%s \ >>> + --grep="[\d]\|" >actual.perl && >>> + test_cmp expect.perl actual.perl >>> + fi && >>
