Daniel Fischer wrote:
I don't know Joy, but probably there the stack is (roughly) a heterogenous list, which is hard to model in Haskell, think of
data Element = Bool Bool | Char Char | Int Int . . . | IntToBool (Int -> Bool) . . .
type Stack = [Element]
and how to define functions for that, urgh.
Not saying it isn't tricky - but thats what the HList library (http://www.cwi.nl/~ralf/HList) implements, a heterogenous list. It works slightly differently using classes, but does abstract the workings enough to be useful, to construct an HList you can do: hlist = "a" .*. (3:Int) .*. False .*. 'v' .*. HNil And provides head/tail functions and other useful list and set operators. Keean.