Method typeCheck

src/chap14/TypeChecker.java:56–60

(TypeEnv tenv)

    @Reviser public static class NegativeEx extends NegativeExpr {
        public NegativeEx(List<ASTree> c) { super(c); }
        public TypeInfo typeCheck(TypeEnv tenv) throws TypeException {
            TypeInfo t = ((ASTreeTypeEx)operand()).typeCheck(tenv);
            t.assertSubtypeOf(TypeInfo.INT, tenv, this);
            return TypeInfo.INT;
        }
    }
    @Reviser public static class BinaryEx extends BinaryExpr {
        protected TypeInfo leftType, rightType;