when is defaulting supposed to occur?

Iavor S. Diatchki diatchki at cse.ogi.edu
Thu Oct 23 16:07:45 EDT 2003


hello,
the problem has to do with the monomorphism restriction
see section 4.5.5 (rule 2)  (or typing hashell in haskell section 11.5.1 
for details).
bye
iavor


Mark Tullsen wrote:

> Note the following program
>  x = 1
>  y = x :: Int
>
> This is accepted by ghc but it is rejected hugs (May 2003 cvs):
>  ERROR "IntegerTest.hs":4 - Type error in type annotation
>  *** Term           : x
>  *** Type           : Integer
>  *** Does not match : Int
>
> My guess is that hugs is doing defaulting after a "declaration group"
> is type-checked, but that ghci leaves 'x' with type 'Num a', then
> processes further declaration groups, and then does defaulting.
>
> I don't see that the report specifies this (did I miss it?).
>
> - Mark
>
>
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-- 
==================================================
| Iavor S. Diatchki, Ph.D. student               | 
| Department of Computer Science and Engineering |
| School of OGI at OHSU                          |
| http://www.cse.ogi.edu/~diatchki               |
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