-//
-//typeExpr :: Expr -> Env Type
-//typeExpr (IntExpr _ _) = Right $ pure IntType
-//typeExpr (CharExpr _ _) = Right $ pure CharType
-//typeExpr (BoolExpr _ _) = Right $ pure BoolType
-//typeExpr (Op1Expr p UnNegation expr) = undef//typeExpr expr
-//// >>= \exprtype->case exprtype of
-//// Right BoolType = Right $ pure BoolType
-//// t = Left $ UnifyError p BoolType exprtype
-//typeExpr (Op1Expr p UnMinus expr) = undef// typeExpr expr
-//// >>= \exprtype->case exprtype of
-//// IntType = Right $ pure IntType
-//// t = Left $ UnifyError p IntType exprtype
-//// typeExpr (Op2Expr Pos Expr Op2 Expr) = undef
-////typeExpr (FunExpr Pos FunCall
-////typeExpr (EmptyListExpr Pos
-////typeExpr (TupleExpr Pos (Expr, Expr)
-////typeExpr (VarExpr Pos VarDef) = undef
-////
-//class unify a :: Type a -> Env a
-//
-//instance unify Type where
-// unify IntType IntType = Right $ pure IntType
-// unify BoolType BoolType = Right $ pure BoolType
-// unify CharType CharType = Right $ pure CharType
-// unify _ _ = undef
+
+typeOp1 :: Pos Expr Type -> Env Type
+typeOp1 p expr rtype = typeExpr expr >>= \exprtype->case exprtype of
+ Left e = pure $ Left e
+ Right rtype = pure $ Right rtype
+ Right (IdType ident) = putIdent ident rtype >>| pure (Right rtype)
+ Right t = pure $ Left $ UnifyError p rtype t
+
+typeExpr :: Expr -> Env Type
+typeExpr (IntExpr _ _) = pure $ Right IntType
+typeExpr (CharExpr _ _) = pure $ Right CharType
+typeExpr (BoolExpr _ _) = pure $ Right BoolType
+typeExpr (Op1Expr p UnNegation expr) = typeOp1 p expr BoolType
+typeExpr (Op1Expr p UnMinus expr) = typeOp1 p expr IntType
+typeExpr (TupleExpr p (e1, e2)) = typeExpr e1
+ >>= \ete1->typeExpr e2 >>= \ete2->pure (
+ ete1 >>= \te1->ete2 >>= \te2->Right $ TupleType (te1, te2))
+//typeExpr (Op1Expr p UnMinus expr) = typeExpr expr
+// >>= \exprtype->case exprtype of
+// IntType = pure $ Right IntType
+// t = Left $ UnifyError p IntType exprtype
+//typeExpr (Op2Expr Pos Expr Op2 Expr) = undef
+//typeExpr (FunExpr Pos FunCall) = undef
+//typeExpr (EmptyListExpr Pos) = undef
+//typeExpr (VarExpr Pos VarDef) = undef
+
+class unify a :: Type a -> Env Type
+
+instance unify Type where
+ unify IntType IntType = pure $ Right IntType
+ unify BoolType BoolType = pure $ Right BoolType
+ unify CharType CharType = pure $ Right CharType
+ unify _ _ = undef