juzu.impl.router.regex.RERenderer Maven / Gradle / Ivy
/*
* Copyright 2013 eXo Platform SAS
*
* 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 juzu.impl.router.regex;
import java.io.IOException;
/**
* Renders a {@link RENode} to its pattern representation.
*
* @author Julien Viet
* @version $Revision$
*/
public class RERenderer extends REVisitor {
public static A render(RENode re, A appendable) throws IOException, NullPointerException {
if (re == null) {
throw new NullPointerException("No null disjunction accepted");
}
if (appendable == null) {
throw new NullPointerException("No null appendable accepted");
}
//
RERenderer renderer = new RERenderer(appendable);
//
re.accept(renderer);
//
return appendable;
}
/** . */
private final Appendable appendable;
public RERenderer(Appendable appendable) {
this.appendable = appendable;
}
protected void visit(RENode.Disjunction disjunction) throws IOException, NullPointerException {
RENode.Alternative alternative = disjunction.getAlternative();
if (alternative != null) {
alternative.accept(this);
}
if (disjunction.hasAlternative() && disjunction.hasNext()) {
appendable.append('|');
}
RENode.Disjunction next = disjunction.getNext();
if (next != null) {
next.accept(this);
}
}
protected void visit(RENode.Alternative alternative) throws IOException, NullPointerException {
alternative.getExpr().accept(this);
RENode.Alternative next = alternative.getNext();
if (next != null) {
visit(next);
}
}
protected void visit(RENode.Assertion.Begin expr) throws IOException {
appendable.append('^');
if (expr.getQuantifier() != null) {
expr.getQuantifier().toString(appendable);
}
}
protected void visit(RENode.Assertion.End expr) throws IOException {
appendable.append('$');
if (expr.getQuantifier() != null) {
expr.getQuantifier().toString(appendable);
}
}
protected void visit(RENode.Group expr) throws IOException {
appendable.append(expr.getType().getOpen());
this.visit(expr.getDisjunction());
appendable.append(expr.getType().getClose());
if (expr.getQuantifier() != null) {
expr.getQuantifier().toString(appendable);
}
}
protected void visit(RENode.Char expr) throws IOException {
Literal.escapeTo(expr.getValue(), appendable);
if (expr.getQuantifier() != null) {
expr.getQuantifier().toString(appendable);
}
}
protected void visit(RENode.Any expr) throws IOException {
appendable.append('.');
if (expr.getQuantifier() != null) {
expr.getQuantifier().toString(appendable);
}
}
protected void visit(RENode.CharacterClass expr) throws IOException {
appendable.append("[");
expr.getExpr().accept(this);
appendable.append("]");
if (expr.getQuantifier() != null) {
expr.getQuantifier().toString(appendable);
}
}
protected void visit(RENode.CharacterClassExpr.Not expr) throws IOException {
boolean needBrace = false;
for (RENode current = expr.getParent();current != null;current = current.getParent()) {
if (current instanceof RENode.CharacterClassExpr.Or) {
needBrace = true;
break;
}
else if (current instanceof RENode.CharacterClassExpr.And) {
needBrace = true;
break;
}
else if (current instanceof RENode.CharacterClassExpr.Not) {
needBrace = true;
break;
}
}
if (needBrace) {
appendable.append("[");
}
appendable.append("^");
expr.getNegated().accept(this);
if (needBrace) {
appendable.append(']');
}
}
protected void visit(RENode.CharacterClassExpr.Or expr) throws IOException {
expr.getLeft().accept(this);
expr.getRight().accept(this);
}
protected void visit(RENode.CharacterClassExpr.And expr) throws IOException {
expr.getLeft().accept(this);
appendable.append("&&");
expr.getRight().accept(this);
}
protected void visit(RENode.CharacterClassExpr.Range expr) throws IOException {
visit(expr.getFrom());
appendable.append('-');
visit(expr.getTo());
}
protected void visit(RENode.CharacterClassExpr.Char expr) throws IOException {
Literal.escapeTo(expr.getValue(), appendable);
}
}