Re: [Haskell-cafe] Closed Classes

G'day all. Quoting camarao@dcc.ufmg.br:

Informally, what I see as the defining rule for "closed world" is: "an expression is typed according to the set of definitions that are visible in the context in which it is used". Other possibilities exist, but the nice thing about this is that it is an extension of what happens without overloading.

Except that you can choose to export or not export a non-overloaded function from a module, but you don't have that choice with typeclass instances. Cheers, Andrew Bromage