cmpstr/dist/cjs/phonetic/Cologne.cjs

CmpStr is a lightweight, fast and well performing package for calculating string similarity

// CmpStr v3.0.1 dev-052fa0c-250614 by Paul Köhler @komed3 / MIT License
'use strict';

var Phonetic = require('./Phonetic.cjs');

/**
 * Cologne Phonetic Algorithm
 * src/phonetic/Cologne.ts
 *
 * @see https://en.wikipedia.org/wiki/Cologne_phonetics
 *
 * Cologne phonetics, also known as `Kölner Phonetik` or the `Cologne process`,
 * is a phonetic algorithm that assigns a sequence of digits, referred to as the
 * phonetic code, to words. The purpose of this method is to ensure that words
 * with identical sounds receive the same code. This algorithm can facilitate a
 * similarity search among words.
 *
 * Cologne phonetics is associated with the well-known Soundex phonetic algorithm,
 * yet it is specifically optimized for the German language. This algorithm was
 * introduced by Hans Joachim Postel in 1969.
 *
 * The Cologne phonetic algorithm works by mapping letters to digits, ignoring
 * certain letters, and applying specific rules to handle character combinations.
 *
 * @module Phonetic/Cologne
 * @author Paul Köhler (komed3)
 * @license MIT
 */
/**
 * Cologne class extends the Phonetic class to implement the Cologne phonetic algorithm.
 */
class Cologne extends Phonetic.Phonetic {
  // Default options for the Cologne phonetic algorithm
  static default = { map: 'default', delimiter: ' ', length: -1, dedupe: true };
  /**
   * Constructor for the Cologne class.
   *
   * Initializes the Cologne phonetic algorithm with the mapping and options.
   *
   * @param {PhoneticOptions} [opt] - Options for the Cologne phonetic algorithm
   */
  constructor(opt = {}) {
    super('cologne', opt);
  }
  /**
   * Adjusts the phonetic code by removing all '0's except the first character.
   *
   * @param {string} code - The phonetic code to adjust
   * @returns {string} - The adjusted phonetic code
   */
  adjustCode(code) {
    return code.slice(0, 1) + code.slice(1).replaceAll('0', '');
  }
}
// Register the Cologne algorithm in the phonetic registry
Phonetic.PhoneticRegistry.add('cologne', Cologne);
// Register the Cologne phonetic mapping
Phonetic.PhoneticMappingRegistry.add('cologne', 'default', {
  map: {
    a: '0',
    ä: '0',
    e: '0',
    i: '0',
    j: '0',
    o: '0',
    ö: '0',
    u: '0',
    ü: '0',
    y: '0',
    b: '1',
    p: '1',
    d: '2',
    t: '2',
    f: '3',
    v: '3',
    w: '3',
    g: '4',
    k: '4',
    q: '4',
    l: '5',
    m: '6',
    n: '6',
    r: '7',
    c: '8',
    s: '8',
    ß: '8',
    z: '8',
    x: '48'
  },
  ignore: ['h'],
  ruleset: [
    { char: 'p', next: ['h'], code: '3' },
    {
      char: 'c',
      position: 'start',
      next: ['a', 'h', 'k', 'l', 'o', 'q', 'r', 'u', 'x'],
      code: '4'
    },
    {
      char: 'c',
      next: ['a', 'h', 'k', 'o', 'q', 'u', 'x'],
      prevNot: ['s', 'z'],
      code: '4'
    },
    { char: 'd', next: ['c', 's', 'z'], code: '8' },
    { char: 't', next: ['c', 's', 'z'], code: '8' },
    { char: 'x', prev: ['c', 'k', 'q'], code: '8' }
  ]
});

exports.Cologne = Cologne;
//# sourceMappingURL=Cologne.cjs.map