On Tuesday, 2003-08-05, 15:22, CEST, Nick Name wrote: > [...] > > Is there any way to parametrize a type by a value, rather than another > > type? What I would like to do is to define "list of length 3" and "list of > > length 4" as separate parametrization of the same type, such that I could > > write functions that accept lists (under my new typename) of any length as > > long as parameters have the same length. The goal is to remove the need > > for runtime checks all over the code. > > This is called "dependent types" and is not a feature of haskell (nor of any > language that I know); there was "cayenne" (try a google search) but I don't > believe it is still mantained.
Well, there are, e.g., Ada and C++ which allow types to be parametrized by values. The point is that they obviously still use runtime checks, it's just that you don't have to code these checks explicitely. > BTW, why is there no general interest for such a thing as dependent types? What negative consequences does their implementation have? I think, sometimes they could be quite handy. > V. W. ;-) _______________________________________________ Haskell-Cafe mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell-cafe
