Two-argument function composition

Haskell

Public Domain

Like (.), but for function pairings that take an extra argument on one side or the other

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compose composition function functional functions Haskell 
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infixr 9 .$., $..

(.$.) :: (a -> b -> c) -> (d -> b) -> a -> d -> c
(.$.) f g x = f x . g  -- equivalent to ``(.$.) f g x y = f x (g y)''

($..) :: (a -> b) -> (c -> d -> a) -> c -> d -> b
($..) f g x = f . g x  -- equivalent to ``($..) f g x y = f (g x y)''