On Oct 11, 2008, at 2:54 PM, Bit Connor wrote:
Smart constructors are nice but if your module doesn't also export the regular constructor then you can't pattern match against it.
It would be cool if there was a way to export constructors from a module, but only for use in pattern matching and not constructing new values.
I suppose you could make a new data type to pattern match against. For example, say you have data Foo A B = <hidden constructors> foo :: A -> B -> Foo A B -- smart constructor You could introduce and export data FooView = Foo A B | <other possible deconstructions> fooView :: Foo A B -> FooView A B You could even redefine the smart constructor as foo : FooView A B -> Foo A B ... if you wanted. - Jake