Method typeCheckForAssign

src/chap14/TypeChecker.java:39–52

(TypeEnv tenv, TypeInfo valueType)

                return type;
        }
        public TypeInfo typeCheckForAssign(TypeEnv tenv, TypeInfo valueType)
            throws TypeException
        {
            type = tenv.get(nest, index);
            if (type == null) {
                type = valueType;
                tenv.put(0, index, valueType);
                return valueType;
            }
            else {
                valueType.assertSubtypeOf(type, tenv, this);
                return type;
            }
        }
    }
    @Reviser public static class NegativeEx extends NegativeExpr {
        public NegativeEx(List<ASTree> c) { super(c); }