Dominic Steinitz schrieb:
Andrew Coppin <andrewcoppin <at> btinternet.com> writes:

  
I just found it rather surprising. Every time *I* try to compose with 
functions of more than 1 argument, the type checker complains. 
Specifically, suppose you have

  foo = f3 . f2 . f1

Assuming those are all 1-argument functions, it works great. But if f1 
is a *two* argument function (like map is), the type checker refuses to 
allow it, and I have to rewrite it as

  foo x y = f3 $ f2 $ f1 x y

    
Look at the type of (.).(.) which should tell you how to compose functions 
with more than one variable. Mind you, I don't think it improves readability.

Dominic.
  
Interesting function. It got a sibling: (.)(.) :: (a1 -> b -> c) -> a1 -> (a -> b) -> a -> c

Anybody knows how to intepret that? I tried to call it with (++) "t" (++"s") "it" but suddenly got distracted.