Word Suggestion Service

word-suggestion-service.js

function WordSuggestionService(words) {
  this.words = words;
  this.levenshtein = function(a, b) {
    // special cases
    if (a === b) { return 0; }
    if (a === '') { return b.length; }
    if (b === '') { return a.length; }
    // determine longer string
    let short = (a.length <= b.length) ? a : b;
    let long = (a.length <= b.length) ? b : a;
    // init vectors
    let vector1 = [];
    let vector2 = [];
    vector2.length = long.length + 1;
    for (let i = 0, max = long.length; i <= max; i++) { vector1.push(i); } // prefill vector1
    for (let i = 0, iMax = short.length; i < iMax; i++) {
      // vector2 - current distance from previous row
      vector2[0] = i + 1;
      for (let j = 0, jMax = long.length; j < jMax; j++) {
        const increment = (short[i] === long[j]) ? 0 : 1;
        vector2[j + 1] = Math.min(vector2[j] + 1, vector1[j + 1] + 1, vector1[j] + increment);
      }
      // copy vector2 to vector1 for next iteration
      vector2.forEach((item, index) => vector1[index] = item);
    }
    return vector2[long.length]; // return last element of vector2
  }
}

WordSuggestionService.prototype.suggest = function(term) {
  let diff = [];
  this.words.forEach(word => {
    diff.push(this.levenshtein(term, word));
  });
  const minIndex = diff.indexOf(Math.min(...diff));
  return this.words[minIndex];
}

const service = new WordSuggestionService(['javascript', 'java', 'ruby', 'php', 'python', 'coffeescript']);
const suggestion = service.suggest('heaven'); // java

WordSuggestionService.markdown

Word Suggestion Service

Utilizes Levenshtein Distance algorythm to suggest a most similar word to the provided term. The service uses a words dictionary provided as a parameter on service instantiation new WordSuggestionService(['javascript', 'java', 'ruby', 'php', 'python', 'coffeescript']). The service's instance method suggest('heaven') returns a suggestion.

A script by V.

License.