$.RangeMapClass = RangeMap = createClass({ init: function (map) { var key, range, rangelist = []; for (key in map) { if (map.hasOwnProperty(key) && typeof key === 'string' && key.indexOf(':') > -1) { range = key.split(':'); range[0] = range[0].length === 0 ? -Infinity : parseFloat(range[0]); range[1] = range[1].length === 0 ? Infinity : parseFloat(range[1]); range[2] = map[key]; rangelist.push(range); } } this.map = map; this.rangelist = rangelist || false; }, get: function (value) { var rangelist = this.rangelist, i, range, result; if ((result = this.map[value]) !== undefined) { return result; } if (rangelist) { for (i = rangelist.length; i--;) { range = rangelist[i]; if (range[0] <= value && range[1] >= value) { return range[2]; } } } return undefined; } }); // Convenience function $.range_map = function(map) { return new RangeMap(map); };