From: Joe Cheng <code@...>
Date: 2004-10-05T13:49:51+09:00
Subject: Re: Regexp match question on interpolated strings...

Richard Kilmer wrote:
> If I had the source for a string:
> 
> "name = #{person.first_name+" "+person.last_name} ... Ok?"
> 
> And assuming I could find the first and last double quotes, how would I
> parse out the #{ ... } with a regular expression since anything can fall
> between the #{ ... } braces in a string?

Hmmm, if I understand your question, and if you really knew where the 
first and last double quotes were, you could calculate the number of 
chars between them, and do something like this:

/#\{.*?\".{<number_of_chars>}\".*?}/

But it seems like if you want to be able to get more dynamic/flexible 
than that, you really want to parse the expression for real--which is 
something I believe regexes aren't powerful enough for.  You'd either 
have to write a parser by hand, or use something like racc:

http://i.loveruby.net/en/prog/racc.html