Rambox-CE/ext/src/sparkline/RangeMap.js

/**
 * Base class for Range Map
 */
Ext.define('Ext.sparkline.RangeMap', {
    constructor: 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];
                }
            }
        }
    }
});