Hello Thomas,
Sunday, May 15, 2005, 7:26:11 PM, you wrote:
TD> data SCode = SModule String [Export] | SUnknown
TD> It would be useful to specify a function as so:
TD> doSomethingToAModule :: SCode(SModule) -> SomeRandomOtherType
because constructor names are globally unique, this can be written just as:
doSomethingToAModule :: SModule -> SomeRandomOtherType
i also needed similar feature, but to keep data as part of complex
structure:
data X = X { field1 :: SModule
, field2 :: ...
}
if Haskell will allow to define new types by or'ing existing ones,
whis will solve both our problems (modulo syntax sugar):
data SModule = SModule String [Export]
data SUnknown = SUnknown
data SCode = SModule | SUnknown
this extension will even allow to create ad-hoc polymorphic functions
(!). but on other side - increased complexity and ambiguousity of type
inferencing
may be, adding only ability to "decompose" existing multi-variant
types, but not to compose arbitrary types will not give such pressure
on type inferencing system
--
Best regards,
Bulat mailto:[EMAIL PROTECTED]
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