definition module AST

from Data.Maybe import :: Maybe
from StdOverloaded import class toString, class ==, class zero, class <

:: Pos = {line :: Int, col :: Int}
:: AST = AST [FunDecl]
:: VarDecl = VarDecl Pos (Maybe Type) String Expr
:: TVar :== String
:: Type 
	= TupleType (Type, Type)
	| ListType Type
	| IdType TVar 
	| IntType 
	| BoolType
	| CharType
    | VoidType
	| FuncType Type
    | (->>) infixl 7 Type Type
:: Expr 
	= VarExpr Pos VarDef
	| Op2Expr Pos Expr Op2 Expr
	| Op1Expr Pos Op1 Expr
	| IntExpr Pos Int
	| CharExpr Pos Char
	| BoolExpr Pos Bool
	| FunExpr Pos String [Expr] [FieldSelector]
	| EmptyListExpr Pos 
	| TupleExpr Pos (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 Pos String [String] (Maybe Type) [VarDecl] [Stmt]
:: Stmt 
	= IfStmt Expr [Stmt] [Stmt]
	| WhileStmt Expr [Stmt]
	| AssStmt VarDef Expr
	| FunStmt String [Expr] [FieldSelector]
	| ReturnStmt (Maybe Expr)

instance toString Pos
instance toString Type
instance toString AST
instance toString FieldSelector
instance toString Op2
instance toString Expr
instance toString VarDecl

instance zero Pos
instance == Op1
instance == Op2
instance < Op1
instance < Op2
instance == Type