Re: [Haskell-cafe] Irritating Referential Transparency behavior?

10 Aug 2014


      Am 08/10/2014 08:52 PM, schrieb Albert Y. C. Lai:
...
On 14-08-10 02:20 PM, martin wrote:
...
exProcess2 pState loc = LP {lstep = xxx}
         where
             xxx = myStep pState
vs
...
exProcess2 pState loc = LP {lstep = myStep pState}
         where
             xxx = myStep pState
The monomorphism restriction requires assigning a monomorphic (non-polymorphic) type to xxx. The assignment could come
from declaring xxx's type (which you didn't do) or inferring from use sites (which you had in one example but not in
another). When both are lacking, a job that needs done can't be done, and it is an error.
Very clear explanation. Thanks