From: Richard Kilmer <rich@...>
Date: 2004-10-06T01:06:38+09:00
Subject: Re: Regexp match question on interpolated strings...

I am working in an environment that is neither Ruby or Perl.  The piece of
code looks something like this:

    { name = "Double Quoted String";
      begin = "\"";
      end = "\"";  
      foregroundColor = "#66CC33";
      patterns = (
        { name = "Interpolated String";
          match = "#\\{([^\\}]*)\\}";
          foregroundColor = "#aaaaaa";
        }
      );
    },

This is a syntax highlighting system for an editor.  As you can see, you can
use either begin="regexp"; end="regexp" or match="regexp" and patterns can
be nested.

What I have works...assuming that the code inside the #{ ... } does not,
itself contain braces (which is limiting, I know).

-rich


On 10/5/04 10:04 AM, "James Edward Gray II" <james@grayproductions.net>
wrote:

> On Oct 5, 2004, at 4:09 AM, Brian Schr�der wrote:
> 
>> Regular expressions are not able to "count" more than a finite number
>> of states, and the number of states is fixed at compile time. That is
>> because regular expressions map to finite automata. So it is
>> impossible to match opening and closing braces in an unknown
>> expression. For this to work always you need a model that can enter
>> unbounded many states.
> 
> Just for the sake of clarity, you are speaking of Ruby's regular
> expressions here.  Perl's regex engine has no such limitation.  Using
> the (?? ... ) construct, Perl regular expressions can parse balanced
> delimiters.  I miss this feature and would love to see Ruby add
> something similar in the future.
> 
> James Edward Gray II
> 
> 
>