front_end/core/common/TextDictionary.ts

/*
 * Copyright (C) 2013 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

import {Trie} from './Trie.js';

export class TextDictionary {
  readonly words: Map<string, number>;
  readonly index: Trie;
  constructor() {
    this.words = new Map();
    this.index = new Trie();
  }

  addWord(word: string): void {
    let count = this.words.get(word) || 0;
    ++count;
    this.words.set(word, count);
    this.index.add(word);
  }

  removeWord(word: string): void {
    let count = this.words.get(word) || 0;
    if (!count) {
      return;
    }
    if (count === 1) {
      this.words.delete(word);
      this.index.remove(word);
      return;
    }
    --count;
    this.words.set(word, count);
  }

  wordsWithPrefix(prefix: string): string[] {
    return this.index.words(prefix);
  }

  hasWord(word: string): boolean {
    return this.words.has(word);
  }

  wordCount(word: string): number {
    return this.words.get(word) || 0;
  }

  reset(): void {
    this.words.clear();
    this.index.clear();
  }
}