definition module parse

from Data.Either import :: Either
from Data.Maybe import :: Maybe

import lex

:: ParserOutput :== Either String AST

:: AST = AST [VarDecl] [FunDecl]
:: VarDecl = VarDecl String Type Expr
:: Type 
	= TupleType Type Type
	| ListType Type
	| IdType String
	| IntType 
	| BoolType
	| CharType
	| VarType

:: Expr 
	= VarExpr String (Maybe FieldSelector)
	| Op2Expr Expr Op2 Expr //TODO, iets met associativiteit wat niet weet hoe
	| Op1Expr Op1 Expr
	| IntExpr Int
	| CharExpr Char
	| BoolExpr Bool
	| EmptyListExpr
	| TupleExpr Expr Expr

:: FieldSelector = FieldHd | FieldTl | FieldFst | FieldSnd
:: Op1 = UnNegation | UnMinus
:: Op2 = BiPlus | BiMinus | BiTimes | BiDivide | BiMod | BiEquals | BiLesser |
	BiGreater | BiLesserEq | BiGreaterEq | BiUnEqual | BiAnd | BiOr | BiCons

//TODO

:: FunDecl = Stub

parse :: LexerOutput -> ParserOutput