| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.openjpa.kernel.exps; |
| |
| import org.apache.openjpa.kernel.StoreContext; |
| |
| /** |
| * Value produced by a mathematical operation on one value. |
| * |
| * @author Abe White |
| */ |
| abstract class UnaryMathVal |
| extends Val { |
| |
| private final Val _val; |
| |
| /** |
| * Constructor. Provide the value to operate on. |
| */ |
| public UnaryMathVal(Val val) { |
| _val = val; |
| } |
| |
| public Class getType() { |
| return getType(_val.getType()); |
| } |
| |
| public void setImplicitType(Class type) { |
| } |
| |
| protected Object eval(Object candidate, Object orig, |
| StoreContext ctx, Object[] params) { |
| Object o1 = _val.eval(candidate, orig, ctx, params); |
| return operate(o1, _val.getType()); |
| } |
| |
| /** |
| * Return the type of this value based on the numeric type being operated |
| * on. |
| */ |
| protected abstract Class getType(Class c); |
| |
| /** |
| * Return the result of this mathematical operation on the given value. |
| */ |
| protected abstract Object operate(Object o, Class c); |
| |
| public void acceptVisit(ExpressionVisitor visitor) { |
| visitor.enter(this); |
| _val.acceptVisit(visitor); |
| visitor.exit(this); |
| } |
| } |