var iterate = require('./lib/iterate.js')
, initState = require('./lib/state.js') , terminator = require('./lib/terminator.js') ;
// Public API module.exports = serialOrdered; // sorting helpers module.exports.ascending = ascending; module.exports.descending = descending;
/**
* Runs iterator over provided sorted array elements in series * * @param {array|object} list - array or object (named list) to iterate over * @param {function} iterator - iterator to run * @param {function} sortMethod - custom sort function * @param {function} callback - invoked when all elements processed * @returns {function} - jobs terminator */
function serialOrdered(list, iterator, sortMethod, callback) {
var state = initState(list, sortMethod); iterate(list, iterator, state, function iteratorHandler(error, result) { if (error) { callback(error, result); return; } state.index++; // are we there yet? if (state.index < (state['keyedList'] || list).length) { iterate(list, iterator, state, iteratorHandler); return; } // done here callback(null, state.results); }); return terminator.bind(state, callback);
}
/*
* -- Sort methods */
/**
* sort helper to sort array elements in ascending order * * @param {mixed} a - an item to compare * @param {mixed} b - an item to compare * @returns {number} - comparison result */
function ascending(a, b) {
return a < b ? -1 : a > b ? 1 : 0;
}
/**
* sort helper to sort array elements in descending order * * @param {mixed} a - an item to compare * @param {mixed} b - an item to compare * @returns {number} - comparison result */
function descending(a, b) {
return -1 * ascending(a, b);
}