Type classes and code generation
Hal Daume III
Tue, 17 Jun 2003 07:50:23 -0700 (PDT)
(Moved to the Cafe)
> Yes, exactly. Every class is translated to a data type declaration,
> and every instance is translated to an element of that data type - a
> dictionary. (Note that you can't actually write those declarations in
> Haskell 98 in general, because they can have polymorphic fields; but
> this is a simple extension to the language).
Keith, could you elaborate on this parenthetical? Under what
circumstances can you not create the dictionary datatype for a class in
Haskell 98 (where the class itself is H98 :P)?