From: Krishna Dole <kpd@...>
Date: 2003-04-24T08:00:55+09:00
Subject: grep and regular expressions in ruby

I'm quite taken with ruby, but recently I ran into trouble using grep. I
have two questions: first, is there a way to call grep with multiple
regexps? For example, if you had
	ar = ["cat", "dog", "smallcat"]

and you only wanted strings matching  both "small" and "cat", in perl I
think you could do something like
	ar2 = grep(( /cat/ and /small/ ), ar );

but in ruby it seems like you have to call grep twice
	ar2 = ar.grep(/cat/).grep(/small/)

is there a more elegant solution?

The second question concerns regexps: how do you indicate that you don't
want to match the specified pattern? For example, if I only wanted strings
containing "cat" but not containing "small". Once again, I think the perl
would look like this:
	ar2 = grep(( /cat/ and !/small/ ), ar );

but '!' doesn't work for me in ruby. So far I haven't found anything about
this in Pickaxe or on the web.

thanks,
Krishna