definition module ast

from Data.Either import :: Either
from StdOverloaded import class toString

:: AST = AST [Function]

:: Function = Function [Char] [[Char]] Expression

:: Expression
	= Lit Value
	| Var [Char]
	| App Expression Expression
	| Lambda [Char] Expression
	| Builtin [Char] [Expression]
	| Let [Char] Expression

:: Value
	= Int Int
	| Bool Bool
	| Func Int [Expression] ([Expression] -> Expression)

:: Type
	= TVar [Char]
	| TInt
	| TBool
	| TFun Type Type

instance toString AST, Function, Expression, Value, Type