com.google.gwt.dev.generator.NameFactory Maven / Gradle / Ivy
/*
* Copyright 2007 Google Inc.
*
* 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 com.google.gwt.dev.generator;
import java.util.Collection;
import java.util.HashSet;
import java.util.Set;
/**
* Generates unqiue identifiers. Use this class to avoid generating conflicting
* names with user code. This class isn't smart enough to know about scopes
* (which isn't generally a problem for generators in any case).
*/
public class NameFactory {
private final Set usedNames = new HashSet();
/**
* Creates a new NameFactory that knows about
* existingNames.
*
* @param existingNames a list of names that may be null.
*/
public NameFactory(Collection existingNames) {
if (existingNames == null) {
return;
}
usedNames.addAll(existingNames);
}
/**
* Creates a new NameFactory that doesn't know about any
* existing names.
*/
public NameFactory() {
this(null);
}
/**
* Reserves a known name. Asserts that the name is not already in this set.
*
* @param name a not null name
*/
public void addName(String name) {
assert !usedNames.contains(name);
usedNames.add(name);
}
/**
* Creates a new unique name based off of name and adds it to
* the list of known names.
*
* @param name a not null name to base the new unique name from
* @return a new unique, not null name. This name may be
* possibly identical to name.
*/
public String createName(String name) {
String newName = name;
for (int count = 0; true; ++count) {
if (usedNames.contains(newName)) {
newName = name + count;
} else {
usedNames.add(newName);
return newName;
}
}
}
}