[Haskell-beginners] f . g or f g or f $ g?

Martin Drautzburg Martin.Drautzburg at web.de
Fri Feb 1 20:42:56 CET 2013

Hello all

I frequently get confused over f . g vs f g. I do understand the following


g :: a->b
f :: b ->c

f.g :: a->c


f g 

is a type error, because then f would have to accept a function (a->b) as its 
first parameter, but it only accepts a b.

Is there a way to easily remember when to use f.g and when to use f g without 
having to do this type algebra.


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