1var iterate = require('./lib/iterate.js') 2 , initState = require('./lib/state.js') 3 , terminator = require('./lib/terminator.js') 4 ; 5 6// Public API 7module.exports = parallel; 8 9/** 10 * Runs iterator over provided array elements in parallel 11 * 12 * @param {array|object} list - array or object (named list) to iterate over 13 * @param {function} iterator - iterator to run 14 * @param {function} callback - invoked when all elements processed 15 * @returns {function} - jobs terminator 16 */ 17function parallel(list, iterator, callback) 18{ 19 var state = initState(list); 20 21 while (state.index < (state['keyedList'] || list).length) 22 { 23 iterate(list, iterator, state, function(error, result) 24 { 25 if (error) 26 { 27 callback(error, result); 28 return; 29 } 30 31 // looks like it's the last one 32 if (Object.keys(state.jobs).length === 0) 33 { 34 callback(null, state.results); 35 return; 36 } 37 }); 38 39 state.index++; 40 } 41 42 return terminator.bind(state, callback); 43} 44