Daniel Fischer <daniel.is.fisc...@web.de> writes: > On Wednesday 17 November 2010 19:09:16, Jerzy M wrote: >> Hallo, >> let me take this simple function: (2*). >> If I check its type >> >> :t (2*) >> >> I'll obtain >> (2*) :: (Num a) => a -> a >> >> But now it suffices to write >> g = (2*) >> and check >> >> :t g >> >> to obtain >> g :: Integer -> Integer >> >> One more combination, now I write >> h x = (2*) x >> and check once more >> >> :t h >> >> to get >> h :: (Num a) => a -> a >> >> So my question is: why (in this second example) Integer is inferred? >> What makes a difference? > > The monomorphism restriction.
And default. If you load this into ghci module Main where default (Int) g = (2*) main = putStrLn "foo" and type :t g you'll get Int -> Int -- Jón Fairbairn jon.fairba...@cl.cam.ac.uk _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
