26 Jan
2006
26 Jan
'06
8:28 p.m.
john:
I have often wanted a shorthand syntax for testing if a value matches a given pattern. I want to implement such an extension for jhc but can't decide an appropriate syntax so I thought I'd ask the group. basically I want something like
/Left (Just _)/ expands to
\x -> case x of Left (Just _) -> True _ -> False
Something like pattern guards? f x | Just _ <- x = putStrLn "something" -- Don