/*
Copyright 2009 Tomer Gabel
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.
ant-intellij-tasks project (http://code.google.com/p/ant-intellij-tasks/)
$Id: CharPrefixTree.java 106 2009-09-30 02:07:29Z tomergabel $
*/
//package com.tomergabel.util;
import java.util.*;
public class CharPrefixTree implements Collection {
private static class Node {
public Map children = new HashMap();
}
Node root = null;
@Override
public Iterator iterator() {
throw new UnsupportedOperationException();
}
@Override
public Object[] toArray() {
throw new UnsupportedOperationException();
}
@Override
public T[] toArray( final T[] a ) {
throw new UnsupportedOperationException();
}
@Override
public int size() {
throw new UnsupportedOperationException();
}
@Override
public boolean isEmpty() {
return this.root != null;
}
@Override
public boolean add( final String s ) {
Node node = this.root;
if ( node == null )
node = this.root = new Node();
boolean isNew = false;
for ( int i = 0; i < s.length(); ++i ) {
final char c = s.charAt( i );
if ( node.children.containsKey( c ) )
node = node.children.get( c );
else {
isNew = true;
node.children.put( c, node = new Node() );
}
}
return isNew;
}
@Override
public boolean remove( final Object o ) {
if ( o instanceof String ) {
final String s = (String) o;
Node node = this.root;
for ( int i = 0; node != null && i < s.length() - 1; ++i )
node = node.children.get( s.charAt( i ) );
return node != null;
} else throw new ClassCastException();
}
@Override
public boolean containsAll( final Collection c ) {
for ( final Object o : c )
if ( !contains( o ) )
return false;
return true;
}
@Override
public boolean addAll( final Collection c ) {
boolean any = false;
for ( final String s : c )
any |= add( s );
return any;
}
@Override
public boolean removeAll( final Collection c ) {
boolean any = false;
for ( final Object o : c )
any |= remove( o );
return any;
}
@Override
public boolean retainAll( final Collection c ) {
throw new UnsupportedOperationException();
}
@Override
public void clear() {
this.root = null;
}
@Override
public boolean contains( final Object o ) {
if ( o instanceof String ) {
final String s = (String) o;
if ( s.length() == 0 )
return !isEmpty();
Node node = this.root;
for ( int i = 0; node != null && i < s.length(); ++i )
node = node.children.get( s.charAt( i ) );
return node != null;
} else throw new ClassCastException();
}
}