serialOrdered.js (1751B)
1 var iterate = require('./lib/iterate.js') 2 , initState = require('./lib/state.js') 3 , terminator = require('./lib/terminator.js') 4 ; 5 6 // Public API 7 module.exports = serialOrdered; 8 // sorting helpers 9 module.exports.ascending = ascending; 10 module.exports.descending = descending; 11 12 /** 13 * Runs iterator over provided sorted array elements in series 14 * 15 * @param {array|object} list - array or object (named list) to iterate over 16 * @param {function} iterator - iterator to run 17 * @param {function} sortMethod - custom sort function 18 * @param {function} callback - invoked when all elements processed 19 * @returns {function} - jobs terminator 20 */ 21 function serialOrdered(list, iterator, sortMethod, callback) 22 { 23 var state = initState(list, sortMethod); 24 25 iterate(list, iterator, state, function iteratorHandler(error, result) 26 { 27 if (error) 28 { 29 callback(error, result); 30 return; 31 } 32 33 state.index++; 34 35 // are we there yet? 36 if (state.index < (state['keyedList'] || list).length) 37 { 38 iterate(list, iterator, state, iteratorHandler); 39 return; 40 } 41 42 // done here 43 callback(null, state.results); 44 }); 45 46 return terminator.bind(state, callback); 47 } 48 49 /* 50 * -- Sort methods 51 */ 52 53 /** 54 * sort helper to sort array elements in ascending order 55 * 56 * @param {mixed} a - an item to compare 57 * @param {mixed} b - an item to compare 58 * @returns {number} - comparison result 59 */ 60 function ascending(a, b) 61 { 62 return a < b ? -1 : a > b ? 1 : 0; 63 } 64 65 /** 66 * sort helper to sort array elements in descending order 67 * 68 * @param {mixed} a - an item to compare 69 * @param {mixed} b - an item to compare 70 * @returns {number} - comparison result 71 */ 72 function descending(a, b) 73 { 74 return -1 * ascending(a, b); 75 }