Hello Josh, il 20 agosto 2020 alle 22:02 josh friedlander ha scritto:
i understand that in general $ is a) right-associative and b) lowest-priority. but if so shouldn't these two be roughly the same?
λ take (succ 10) $ cycle "hello world" "hello world"
But not this? λ take $ succ 10 $ cycle "hello world"
[…]
λ> :info ($) ($) :: (a -> b) -> a -> b -- Defined in ‘GHC.Base’ infixr 0 $ So, since `$` is right associative, the expression take $ succ 10 $ cycle "hello world" becomes take (succ 10 (cycle "hello world")) `cycle "hello world"` makes sense, `succ 10` makes sense, `succ 10 anotherArgument` does not. Even `take someStuff` is probably not what you want, since take is usually invoked with two arguments. A useful intuition when you see ($) is `it will evaluate everything on the right of it first`. This way, `not $ xx yy zz` looks right, `take $ xx aa yy qq` less so. Does this help? —F