/*
 * Copyright 2012 Takao Nakaguchi
 *
 * 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 org.trie4j;

import java.util.Map;

/**
 * Represents the Trie that can keep values binded to the key.
 * @author Takao Nakaguchi
 * @param <T> type of the value
 */
public interface MapTrie<T> extends Trie{
	/**
	 * retuns root node.
	 * @return root node.
	 */
	MapNode<T> getRoot();

	/**
	 * gets the value associated with word.
	 * @param word word
	 * @return value. null if word not inserted or inserted with null value.
	 */
	T get(String word);

	/**
	 * insert a word with value.
	 * @param word word to insert.
	 * @param value the value associated with word.
	 * @return old value for word.
	 */
	T insert(String word, T value);

	/**
	 * Put a value associated with existing word.
	 * @param word word to be associated with value. word must be exist in trie.
	 * @param value value
	 * @return old value for word.
	 */
	T put(String word, T value);

	/**
	 * search trie for words contained in query.
	 * If query is "helloworld" and trie contains "he", "hello" and "world",
	 * the words "he" and "hello" will be found.
	 * @param query query
	 * @return Iterable object which iterates found words.
	 */
	Iterable<Map.Entry<String, T>> commonPrefixSearchEntries(String query);

	/**
	 * search trie for words starting prefix.
	 * If prefix is "he" and trie contains "he", "hello" and "world",
	 * the words "he" and "hello" will be found.
	 * @param prefix prefix
	 * @return Iterable object which iterates found words.
	 */
	Iterable<Map.Entry<String, T>> predictiveSearchEntries(String prefix);
}