[Haskell-cafe] Re: what does @ mean?.....

ChrisK <haskell@list.mightyreason.com> wrote:

zeroNothing Nothing = Nothing zeroNothing (Just n) = if n == 0 then Nothing else (Just n)

versus

zeroNothing Nothing = Nothing zeroNothing x@(Just n) = if n == 0 then Nothing else x

versus zeroNothing Nothing = Nothing zeroNothing x = let (Just n) = x in if n == 0 then Nothing else x so, @ is kind of like a let, just with its arguments flipped.