From: Simon Strandgaard <neoneye@...>
Date: 2005-09-02T07:24:05+09:00
Subject: Re: palindrome finder

On 9/1/05, Josh Charles <josh.charles@gmail.com> wrote:
> I've been working on this piece of code and it's starting to drive me
> crazy.  I think it's a problem with reference vs value type, but I'm
> not sure.  I'm just writing a simple program to process a list of
> words and print out all the palindromes (words that read the same
> forward and backward)
[snip]

palindrome = Regexp.new(<<'EOPALIN')
(?x)(?i)\b
	(?:(\S)                (?:\s|\p)*
		(?:\S|(\S)         (?:\s|\p)*
			(?:\S|(\S)     (?:\s|\p)* 
				(?:\S|(\S) (?:\s|\p)* 
				\4)?       (?:\s|\p)* 
			\3)?           (?:\s|\p)*
		\2)?               (?:\s|\p)*
	\1)
\b
EOPALIN

p "Win a Toyota blah".match(palindrome).to_s
p "Why Abba rocks?".match(palindrome).to_s
p "A Mismatch".match(palindrome).to_s


--
Simon Strandgaard