On Tue, Feb 17, 2015 at 1:14 PM, Alexander Berntsen
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On 17/02/15 05:30, Greg Weber wrote:
I had an idea whose goal is to ease people into Foldable, Traversable, etc. There could be a notation that shows the generalization that is occurring.
map :: Functor [_] => (a -> b) -> [a] -> [b]
This means that the syntax for the list type is now syntax for the variable created by the Functor constraint. I don't know how useful this is by itself.
What I *really* want is list-style syntax sugar for pattern matching. I.e.
f = \xs -> case xs of [] -> foo [x] -> bar x [x:y] -> fu x y (x:xs) -> baz x xs
The existing IsList machinery gets you the [], [x], and [x,y] cases, but not (x:xs). -Edward