implementation module ast

import StdEnv
import Text

instance toString AST
where
	toString (AST f) = join "\n" (map toString f)

instance toString Function
where
	toString (Function i a e) = concat [toString i, " ", join " " (map toString a), " = ", toString e]

instance toString Expression
where
	toString (Lit v) = toString v
	toString (Var s) = toString s
	toString (App l r) = "(" +++ toString l +++ " " +++ toString r +++ ")"
	toString (Lambda a e) = "(\\" +++ toString a +++ "." +++ toString e +++ ")"
	toString (Builtin v as) = "'" +++ toString v +++ "'" +++ join " " (map toString as)
	toString _ = abort "toString Expression not implemented"

instance toString Value
where
	toString (Int i) = toString i
	toString (Bool b) = toString b
	toString (Char b) = "'" +++ toString b +++ "'"
	toString (Func a as _) = "Function arity " +++ toString a +++ " curried " +++ join "," (map toString as)