21 Jan
2008
21 Jan
'08
4:56 p.m.
"Alexander Seliverstov"
How does caller choose which particular instance of Num they want?
They specify the type... or just pass the result to something that specifies the type. Try it in ghci: Prelude> let f:: Integral i => Integer -> i; f = fromIntegral Prelude> let g :: Int -> Int; g = id Prelude> :t g (f 5) g (f 5) :: Int Prelude> let h :: Integer -> Integer; h = id Prelude> :t h (f 5) h (f 5) :: Integer Prelude>
What the difference between haskell class and interface in object-oriented languge such Java or C#?
Really they are completely different animals that look a lot alike because they serve similar purposes -- convergent evolution! -- Jón Fairbairn Jon.Fairbairn@cl.cam.ac.uk