POST
X-Face: H#SM:U1U-/6#NN83s6?Die557~]Dfifz~-|V:wSKGL6T-|!qk{U4/M7+k5Py!-{q=2Q/%0@
E29yc_kQC&^
User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.4
Andrew Coppin <[EMAIL PROTECTED]> writes:
> As I lay in bed last night, a curios fact occurred to
> me. (Yes, I don't get out very much...)
You probably ought to get out of bed from time to time, you
know.
> Consider the map function:
>
> map :: (a -> b) -> [a] -> [b]
>
> There are two ways you can think about this function. First,
> you can see it as meaning
>
> map :: (a -> b) -> ([a] -> [b])
>
> Which is beautifully symmetric. Alternatively, you can think
> about how you actually use it:
>
> map :: ((a -> b) -> [a]) -> [b]
No, if you think like that, you're wrong! That would be a
function that takes an object of type ((a->b) -> [a]) and
returns a [b] (which if you think about it, would be an odd
sort of function). (->) associates to the right.
--
Jón Fairbairn [EMAIL PROTECTED]
_______________________________________________
Haskell-Cafe mailing list
Haskell-Cafe@haskell.org
http://www.haskell.org/mailman/listinfo/haskell-cafe
