Presumably not "replace all Ints by Floats"

I've thought about it some more, and I don't think its possible to do what I want using generics... Ideally I would like to achieve the following type transformation: type SqlColumn a = String type TypedExpr a = Int the function would map SqlColumns to TypedExpr... The actual code generates an integer from a sequence to "tag" each column, but for the sake of simplicity, the following types would be sufficient: type SqlColumn a = String type TypedExpr a = String So we take a tuple of any length and return exactly the same tuple, but with the types changed: project :: (SqlColumn a,SqlColumn b) -> (TypedExpr a,TypedExpr b) project :: (SqlColumn a,SqlColumn b,SqlColumn c) -> (TypedExpr a,TypedExpr b,TypedExpr c) What do you think? Regards, Keean Schupke.