hound-search
Lookaround assertions in regular expressions?
If I write a regular expression with a (positive or negative) lookahead (or lookbehind) assertion I get an error saying it's incorrect Perl syntax.
For example to look for the text "function" that's not followed by an underscore, I might use this:
function(?!_)
However that returns the error:
ERROR:error parsing regexp: invalid or unsupported Perl syntax: (?!
However they do work in Perl!
Any ideas?
PS: In this toy example I could use a negated character class function[^_] for searching, but I'm interested in the general case rather than a solution to a specific pattern.
OK, looks like this is a limitation with regex in Go (RE2), rather than a Perl thing:
https://github.com/golang/go/issues/18868 https://github.com/google/re2/issues/156
If there are errors, it may be worthwhile to show a link to some documentation alongside the parsing error. We'd love a PR for that contribution.
