Misc #9801: Regexp documentation for Regexp::EXTENDED is incomplete

• Status: Closed
• Assignee: zzak (zzak _)

[allolex (Damon Davison)]

The documentation for Regexp::EXTENDED, i.e. the x flag says that when it is used, Regexp will ignore all whitespace in the pattern. This is not completely true.

All whitespace is ignored, except for whitespace which has been escaped (\ ) or is within a character class ([ ]). Therefore,

/this will not do what you mean/x # this will not work as you expect

but

/this[ ]will\sdo\ what\s+you\s+mean/x #this will work the same as a pattern without the Regexp::EXTENDED flag

I found looking at the Perl documentation very useful http://perldoc.perl.org/perlre.html#%2fx

[allolex (Damon Davison)]

I have submitted a pull request on GitHub to make this easier. (Before, I didn't know I could!)

https://github.com/ruby/ruby/pull/606

[zzak (zzak _)]

• Status changed from Open to Closed

Fixed by r46096