From: Kero van Gelder <kero@...4050.upc-d.chello.nl>
Date: 2001-07-17T19:46:00+09:00
Subject: [ruby-talk:17983] Re: Regexp - stripping comments

> I'm trying to get the beginning of a line before a comment. A comment is a
> semicolon. The problem I'm having is that the semicolons may be in "" which
> I want to keep.
> 
> For example:
> 
> word1 word2 "some text possibly with ;" + __FILE__ + "some more text"  ;
> comments 

Your familiar with the concept of "string" =~ /regexp/ ?
If so, you probably came up with something like
  if 'if expr ;see' =~ /([^;]*);(.*)/
    p $1, $2
  end
printing the two substrings matching the parts between braces.

But the problem lies in the quoted strings:
  if 'if "blah; blah" ;see' =~ /([^;"]*"[^"]*"[^;"]*);(.*)/
    p $1, $2
  end
will work on this line, but not if there are more "quoted" "strings", so
  if 'if "blah;" and "bah;" ;see' =~ /([^;"]*("[^"]*"[^;"]*)*);(.*)/
    p $1, $2, $3
  end
and $1 still holds the beginning of the line.

Bye,
Kero.

PS: I am not a regexp guru, so I imagine shorter, clearer or more
efficient solutions exist. Plus, next thing he'll ask is how to
escaped double quotes can be allowed in the quoted string (like
'if "bla(\"x;y\")"' ) and I know of no easy extension of my example to
achieve that :(

PS2: Won't match if there is no semicolon on the line, but you can
figure that one out yourself now (hint: ?)

+--- Kero ------------------------------ kero@chello.nl ---+
|  Don't split your mentality without thinking twice       |
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