function signatures

[vitiral]

I don't like them

Today we have

fn foo stk:S, b:S -> U2 do ( ... stuff ... )

I thought I wanted something like this:

fn foo(stk:S, b:S) -> U2 do ( ... stuff ... )

But I think I prefer this

fn foo[stk:S, b:S -> U2] do ( ... stuff ... )

This also lets us create a macro like:

fnTy[stk:S, b:S -> U2]

[vitiral]

This lets us do

absmethod foo[stk:S, b:S -> U2] \ note no `do` or semicolon or anything

[vitiral]

For fnTy we are going to need to support synty functions.

These work kind of like syn functions except that they return a type.

They can be used to create generics as well.

[vitiral]

fixed