Stephen Tetley <stephen.tetley <at> gmail.com> writes: > -- | Compose an arity 1 function with an arity 2 function. > -- B1 - blackbird > oo :: (c -> d) -> (a -> b -> c) -> a -> b -> d > oo f g = (f .) . g > > Extending the arity works quite nicely too: > > -- | Compose an arity 1 function with an arity 3 function. > -- B2 - bunting > ooo :: (d -> e) -> (a -> b -> c -> d) -> a -> b -> c -> e > ooo f g = ((f .) .) . g
And oo = (.).(.) and ooo = (.).(.).(.) There was a suggestion a few years back to standardise these as I recall something like: $0 = $ $1 = . $2 = (.).(.) and so on but nothing came of it. Dominic. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
