14 Dec
2004
14 Dec
'04
7:27 p.m.
Derek Elkins wrote:
Andrew Pimlott wrote:
I think this post should go under the heading "($) considered harmful". I've been bitten by this, and I never use ($) anymore in place of parentheses because it's too tempting to think of it as syntax.
I find this position ridiculous. [...] If you ever make a mistake one way the type checker will tell you.
For what it's worth, this is not true in the presence of implicit parameters: f :: ((?p :: Int) => Int) -> Int f g = let ?p = 1 in g x,y :: Int x = let ?p = 2 in (f ?p) ==> 1 y = let ?p = 2 in (f $ ?p) ==> 2 I wouldn't mind ($) being magical, along the lines of the magical runST in a rank-1 type system. It would be nice to be able to use it in patterns too. -- Ben