regexp: considers "\Q\E*" as valid regexp

Question

dvyukov opened this issue 9 years ago · 4 comments

Regexp package successfully compiles "\Q\E_", while re2 says:
re2/re2.cc:202: Error parsing '\Q\E_': no argument for repetition operator: *

Who is right here? What is the reason for difference?

go version devel +b0532a9 Mon Jun 8 05:13:15 2015 +0000 linux/amd64

Answer 1 · 2015-06-12T16:25:01.000Z

Similar case is "\Q\E{2}"

Answer 2 · 2015-10-14T17:29:03.000Z

Perl and RE2 both reject \Q\E*, so I suppose Go should too, although I don't see how it is really different from (?:)*.

Answer 3 · 2015-11-05T16:37:00.000Z

Now I see it. (?:) is a group.

Answer 4 · 2015-11-25T18:02:12.000Z