2012/12/21 Radical
Sometimes I'll need something like:
if value == Foo then Bar else value
Or some syntactic variation thereof:
case value of { Foo -> Bar; _ -> value }
Is there a better/shorter way to do it? I'm surprised that it's more complicated to substitute a value on its own than e.g. in a list, using filter. Or perhaps I'm missing the right abstraction?
Haskell doesn't offer a compact "ternary operator" or similar construct. In some cases, a local definition and pattern guards is appealing: {-# LANGUAGE PatternGuards #-} f value = ... value' ... where value' | Foo <- value = Bar | otherwise = value This does not really have the intuitive of appeal that a "pattern matching ternary operator" might, though: f value = ... (Foo <- value ? Bar : value) ... In Haskell, working with patterns generally is cleaner with multiple lines and full indentation. -- Jason Dusek pgp // solidsnack // C1EBC57DC55144F35460C8DF1FD4C6C1FED18A2B