definition module parse

from Data.Either import :: Either
from Data.Maybe import :: Maybe
from StdString import class toString

import lex

:: ParserOutput :== Either Error AST

:: AST = AST [VarDecl] [FunDecl]
:: VarDecl = VarDecl Type String Expr
:: Type 
	= TupleType (Type, Type)
	| ListType Type
	| IdType String
	| IntType 
	| BoolType
	| CharType
	| VarType
:: Expr 
	= VarExpr VarDef
	| Op2Expr Expr Op2 Expr
	| Op1Expr Op1 Expr
	| IntExpr Int
	| CharExpr Char
	| BoolExpr Bool
	| FunExpr FunCall
	| EmptyListExpr
	| TupleExpr (Expr, Expr)
:: VarDef = VarDef String [FieldSelector]
:: FieldSelector = FieldHd | FieldTl | FieldFst | FieldSnd
:: Op1 = UnNegation | UnMinus
:: Op2 = BiPlus | BiMinus | BiTimes | BiDivide | BiMod | BiEquals | BiLesser |
	BiGreater | BiLesserEq | BiGreaterEq | BiUnEqual | BiAnd | BiOr | BiCons
:: FunDecl = FunDecl String [String] (Maybe FunType) [VarDecl] [Stmt]
:: FunType = FunType [Type] (Maybe Type)
:: FunCall = FunCall String [Expr]
:: Stmt 
	= IfStmt Expr [Stmt] [Stmt]
	| WhileStmt Expr [Stmt]
	| AssStmt VarDef Expr
	| FunStmt FunCall
	| ReturnStmt (Maybe Expr)

instance toString AST

parser :: LexerOutput -> ParserOutput