atom-nuclide/pkg/nuclide-fuzzy-native/lib/utils.js

A unified developer experience for web and mobile development, built as a suite of features on top of Atom to provide hackability and the support of an active community.

Object.defineProperty(exports, '__esModule', {
  value: true
});

/*
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the license found in the LICENSE file in
 * the root directory of this source tree.
 */

exports.valueComparator = valueComparator;
exports.scoreComparator = scoreComparator;
exports.inverseScoreComparator = inverseScoreComparator;

/**
 * String comparator that lists the capitalized verson of a string before the lowercase version.
 *
 * Apparently String.prototype.localeCompare() is not i18n-aware in Node 0.10.x. There's a ton of
 * debate on this:
 *
 *   https://github.com/joyent/node/issues/6371
 *   https://github.com/joyent/node/issues/7676
 *
 * It appears the version of io.js bundled with Atom has proper i18n support, but it lists
 * lowercase strings before uppercase strings, so we also need this custom function in Atom.
 *
 * @return <0 if a should appear before b in a list; >0 if b should appear before a in a list
 */

function valueComparator(a, b) {
  var len = Math.min(a.length, b.length);
  for (var i = 0; i < len; i++) {
    var charA = a.charAt(i);
    var charB = b.charAt(i);
    if (charA === charB) {
      continue;
    }

    var aUpper = charA.toUpperCase();
    var bUpper = charB.toUpperCase();

    var caseInsensitiveCompare = aUpper.localeCompare(bUpper);
    if (caseInsensitiveCompare !== 0) {
      return caseInsensitiveCompare;
    }

    // If we have reached this point, charA and charB are different, but only one of them is
    // uppercase. The uppercase one should be returned first.
    return charA === aUpper ? -1 : 1;
  }

  return a.length - b.length;
}

/**
 * @return >0 if a is the greater QueryScore; <0 if b is the greater QueryScore.
 */

function scoreComparator(a, b) {
  var cmp = a.score - b.score;
  if (cmp !== 0) {
    return cmp;
  } else {
    return valueComparator(b.value, a.value);
  }
}

function inverseScoreComparator(a, b) {
  return scoreComparator(b, a);
}