From: Stefano Crocco <stefano.crocco@...>
Date: 2008-01-25T22:43:46+09:00
Subject: Re: regex issue

Alle Friday 25 January 2008, Junkone ha scritto:
> my pattern should match either import or delete
> However it does not seem to be working.
>
> irb(main):014:0> pattern="([import]|[delete])"
> => "([import]|[delete])"
> irb(main):015:0> pattern.match("import")
> => #<MatchData:0x2e76f9c>
> irb(main):016:0> $1
> => nil

I see two problems with your code:
1) if you want to check that a string (in your case, 'import') matches a 
pattern, you need to use

string.match(pattern)

which, in your case, is

'import'.match(pattern)

2) in a regexp, the construct [abc] means one character among 'a', 'b' or 'c', 
not (as I guess you think) the string 'abc'. Because of this, the string 'i' 
matches your pattern:

'i'.match(pattern)
=> #<MatchData:0xb7bbed44>

To do what you want, you simply need:

pattern = "(import|delete")
"import".match pattern
=>#<MatchData:0xb7bb7cb0>
$1
=> "import"

I hope this helps

Stefano