That's something I'm working on, actually. I think matching the top stack item(s) fits well into a postfix stack-oriented language. For example: TYPE: Tree

That's something I'm working on, actually. I think matching the top stack item(s) fits well into a postfix stack-oriented language. For example: TYPE: Tree | Branch(Tree,Tree) | Leaf ; :: depth Tree -> Int ; : Branch($,$) depth {depth} dip depth + ; : Leaf depth 1 ; $ is extract, so the pattern Branch($,$) pops the top of the stack and pushes the 2 members. Types and type constructors have to start with a capital letter, but I like the : Pattern word definition ; syntax a lot.