[Haskell-cafe] type inference question

Bulat Ziganshin bulat.ziganshin at gmail.com
Thu Oct 8 11:35:47 EDT 2009


Hello Cristiano,

Thursday, October 8, 2009, 7:14:20 PM, you wrote:

> Could you explain why, under NoMonomorphismRestriction, this typechecks:

> let a = 1 in (a + (1 :: Int),a + (1 :: Float))

> while this not:

> foo :: Num a => a -> (Int,Float)
> foo k = (k + (1 :: Int), k + (1.0 :: Float))

i think it's because type is different:

foo :: (forall a. (Num a) => a) -> (Int,Float)

in first equation it probably inferred correctly



-- 
Best regards,
 Bulat                            mailto:Bulat.Ziganshin at gmail.com



More information about the Haskell-Cafe mailing list