On Fri, 2009-02-13 at 11:45 -0700, John A. De Goes wrote:
On Feb 13, 2009, at 11:32 AM, Jonathan Cast wrote:
I believe the last time it was brought up, the proposal was that type inference should fail on certain typeable terms. That doesn't count.
I'm referring to a rather conservative proposal wherein if there is one and exactly one definition that allows an expression to type, then name overloading in the same scope is permitted.
Aside from exponential performance in pathological (but unlikely) cases, what issue do you have with such a proposal?
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! jcc