On 1/26/06, John Hughes
I'd be against this--its semantics isn't clear enough to me. For example, I usually assume id e = e, for any e, but
id (f _ x) y = id (\y->f y x) y = f y x /= f _ x y = \z -> f z x y
Or would (f _ x) y and f _ x y maybe be different? That would fix the problem above, while introducing another. Please, no!
They should be different for this to work. The reasonable thing to do would be to rewrite every (e _ a1 a2 ... an) as (\x -> (e x a1 a2 ... an)) and the parentheses should be mandatory. Note that this can be done recursively, so that e.g. (f _ y _ t) ==> (\x1 -> (f x1 y _ t)) ==> (\x1 -> (\x2 -> (f x1 y x2 t))) I see this as no worse than operator sections: we already have (- x) and (-) x meaning different things. Having in mind that (e _ ...) is just syntax, it should be easy to keep it separate from application, so f x y z will still be the same as ((f x) y) z.
John
Cheers, Dinko