Re: [Haskell-beginners] Wildcards in expressions

At 9:34 PM -0500 1/25/11, Tom Murphy wrote:

Hi everyone, Any suggestions?

Given that

someList :: [(a,b,String)]

, the expression

(_, _, "Tom") `elem` someList

seems so intuitive that, even though it doesn't work, I've been searching for several hours for something similar.

Do any of you know a way I can pull this off? I know there are plenty of ways to get the functionality, but something similarly intuitive and succinct would be great.

Thanks for the help, Tom

Wildcards (the underscores) can appear only in patterns. You could use a list comprehension, something like: (not . null) [ () | (_, _, "Tom") <- someList ] Dean