benchmark.js

'use strict';

var Benchmark = require('benchmark');
var emojis = require('emojilib');
var nearley = require('nearley');
var emojiGrammar = require('./parsers/emoji.js');
var pegjs = require('pegjs-import');
var pegjsEmoji = pegjs.buildParser('./parsers/emoji.pegjs');
var _ = require('lodash');

function nearleyParse(string) {
  var nearleyEmoji = new nearley.Parser(emojiGrammar.ParserRules,
                                        emojiGrammar.ParserStart);

  nearleyEmoji.feed(string);

  return nearleyEmoji.results;
}

var characters = _(emojis)
  .filter(function (emoji) {
    return emoji.char;
  })
  .map(function (emoji) {
    return emoji.char;
  })
  .value();

var suite = new Benchmark.Suite;

suite
  .add('PegJS', function () {
    characters.forEach(function (emoji) {
      pegjsEmoji.parse(emoji);
    });
  })
  .add('nearley.js', function () {
    characters.forEach(function (emoji) {
      nearleyParse(emoji);
    });
  })
  .on('cycle', function (event) {
    console.log(String(event.target));
  })
  .on('complete', function () {
    console.log('Fastest is ' + this.filter('fastest').pluck('name'));
  })
  .run();

emoji.ne

Emoji
 -> PhoneButton {% id %}
  | EmojiCharacter VariationSelector:? {%
      function (data, location, reject) {
        var e = data[0];
        var v = data[1];

        return (e.join ? e.join('') : e) + (v ? v.join ? v.join('') : v : '');
      }
    %}

PhoneButton
 -> [0-9#*] VariationSelector:? [\u20E3] {%
      function (data, location, reject) {
        return data.join('');
      }
    %}

EmojiCharacter
 -> [\uD83C] [\uDDE6-\uDDFF] [\uD83C] [\uDDE6-\uDDFF]
  | [\uD83C] [\uDC04-\uDFFF]
  | [\uD83D] [\uDC00-\uDE4F]
  | [\uD83D] [\uDE80-\uDEC5]
  | [\u203C-\u3299]
  | [\u24C2]
  | [\u2702-\u27B0]
  | [\u00A9\u00AE]

VariationSelector
 -> [\uFE0E\uFE0F]

emoji.pegjs

Emoji
  = p:PhoneButton
  / e:EmojiCharacter v:VariationSelector? {
    return (e.join ? e.join('') : e) + (v ? v.join ? v.join('') : v : '')
  }

PhoneButton
  = [0-9#*] VariationSelector? '\u20E3' {return text()}

EmojiCharacter
  = [\uD83C][\uDDE6-\uDDFF][\uD83C][\uDDE6-\uDDFF]
  / [\uD83C][\uDC04-\uDFFF]
  / [\uD83D][\uDC00-\uDE4F]
  / [\uD83D][\uDE80-\uDEC5]
  / [\u203C-\u3299]
  / '\u24C2'
  / [\u2702-\u27B0]
  / [\u00A9\u00AE]

VariationSelector
  = [\uFE0E\uFE0F]

result.txt

PegJS x 62.04 ops/sec ±3.87% (67 runs sampled)
nearley.js x 30.54 ops/sec ±2.06% (55 runs sampled)
Fastest is PegJS