[Haskell] simulating dependent types; ghc/ghci discrepancy
Tomasz Zielonka
t.zielonka at students.mimuw.edu.pl
Wed Apr 14 19:24:01 EDT 2004
On Wed, Apr 14, 2004 at 04:58:55PM +0100, Keith Wansbrough wrote:
> > data Show' = forall a . Show a => Show' a
>
> The "forall a. Show a =>" context here has no effect on the
> representation; it merely constrains applications of the data
> constructor Show'. Since you have to say
>
> > print' :: Show' -> IO ()
>
> anyway (thus providing the dictionary) there is no point in storing it.
Aren't you talking about a different declaration?
data Show a => Show' a = Show' a
Best regards,
Tom
--
.signature: Too many levels of symbolic links
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