[Haskell-cafe] Comparing functions

[Brandon Allbery]

On Thu, Jul 11, 2013 at 2:11 PM, Vlatko Basic <vlatko.basic at gmail.com>wrote:

> The problem here isn't quite what you think it is; (==) is not a
> constructor, therefore it is a *variable*. It's exactly the same problem as
>
>      a = 5
>     -- ...
>     foo a = 3 -- this does NOT compare with the previous value of "a";
> it's identical to the next line!
>     foo x = x
>
>    Hm, I thought it is a pattern match with constant, as in f ('a':xs) ==
>

I wonder what you'd make of this definition, then?

    (*) `on` f = \x y -> f x * f y

-- 
brandon s allbery kf8nh                               sine nomine associates
allbery.b at gmail.com                                  ballbery at sinenomine.net
unix, openafs, kerberos, infrastructure, xmonad        http://sinenomine.net
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