Tools for automatically simplifying regexes

Question

I'm trying to squash warnings in an open source project, and

/[\.\,\;\:\(\)\[\]\{\}\<\>\"\'\`\~\/\|\?\!\&\@\#\s\x00-\x1f\x7f]+/

is giving me

(irb):1: warning: character class has duplicated range

Are there any tools that automatically point out which parts of the regexp causes the overlap?

Answer 1

I don't know of any tool, but I've spotted the overlap: \s contains \t, \f, \n and \r, so that overlaps with the \x00-\x1f part.

So, unless there's a way to get Ruby itself to tell you that it found a "problem", you can write this regex as (removing all those unnecessary backslashes along the way):

/[.,;:()\[\]{}<>"'`~\/|?!&@# \x00-\x1f\x7f]+/

Answer 2

If you ever reach that point of desperation, I guess you could put outputting some debug info in Ruby source and rebuild. :) I believe this is the place where the warning is thrown:

https://github.com/ruby/ruby/blob/trunk/regparse.c#L1787