/*
* Copyright 2014 Attila Szegedi, Daniel Dekany, Jonathan Revusky
*
* Licensed 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 freemarker.core;
import freemarker.template.TemplateException;
/**
* Represents a <return> instruction to jump out of a macro.
*/
public final class ReturnInstruction extends TemplateElement {
private Expression exp;
ReturnInstruction(Expression exp) {
this.exp = exp;
}
@Override
void accept(Environment env) throws TemplateException {
if (exp != null) {
env.setLastReturnValue(exp.eval(env));
}
if (nextSibling() != null) {
// We need to jump out using an exception.
throw Return.INSTANCE;
}
if (!(getParentElement() instanceof Macro || getParentElement().getParentElement() instanceof Macro)) {
// Here also, we need to jump out using an exception.
throw Return.INSTANCE;
}
}
@Override
protected String dump(boolean canonical) {
StringBuilder sb = new StringBuilder();
if (canonical) sb.append('<');
sb.append(getNodeTypeSymbol());
if (exp != null) {
sb.append(' ');
sb.append(exp.getCanonicalForm());
}
if (canonical) sb.append("/>");
return sb.toString();
}
@Override
String getNodeTypeSymbol() {
return "#return";
}
public static class Return extends RuntimeException {
static final Return INSTANCE = new Return();
private Return() {
}
}
@Override
int getParameterCount() {
return 1;
}
@Override
Object getParameterValue(int idx) {
if (idx != 0) throw new IndexOutOfBoundsException();
return exp;
}
@Override
ParameterRole getParameterRole(int idx) {
if (idx != 0) throw new IndexOutOfBoundsException();
return ParameterRole.VALUE;
}
@Override
boolean isNestedBlockRepeater() {
return false;
}
}