range.js

/**
 * Emulates python's range() built-in. Returns an array of integers, counting
 * up (or down) from start to end. Note that the range returned is up to, but
 * NOT INCLUDING, end.
 *.
 * @param start  integer from which to start counting. If the end parameter is
 *               not provided, this value is considered the end and start will
 *               be zero.
 * @param end    integer to which to count. If omitted, the function will count
 *               up from zero to the value of the start parameter. Note that
 *               the array returned will count up to but will not include this
 *               value.
 * @return       an array of consecutive integers. 
 */
function range(start, end) {
    if (arguments.length == 1) {
        var end = start;
        start = 0;
    }

    var r = [];
    if (start < end) {
        while (start != end)
            r.push(start++);
    } else {
        while (start != end)
            r.push(start--);
    }
    return r;
}