Re: [Haskell-cafe] Re: Overloading functions based on arguments?

13 Feb 2009


      On Fri, 2009-02-13 at 12:06 -0700, John A. De Goes wrote:
...
On Feb 13, 2009, at 11:49 AM, Jonathan Cast wrote:
...
It breaks type inference.  I explained this at the time.  I can  
explain
it again:
import Data.List
 import Data.Set
 import Data.Map
warmFuzzyThingFirstOperation = map
This gives an error currently.  Quite properly.  But if *any* use of
`map' type-checks, with those imports, why on earth should this one
fail?  You don't want to remove a wart from the language, you want to
introduce one!
Umm, no, that would still give an error. See definition of "one and  
exactly one".
Exactly!  But if it fails, why on earth should any other use of map in
the module succeed?

jcc