superFastSort with sorting function

sortWithParam.js

function superFastSort(t, sortfunction, start, len) {
    "use strict";

    if (!sortfunction || typeof sortfunction !== 'function') {
        sortfunction = function(a, b) {
            return a - b;
        };
    }

    if (start === undefined) {
        start = 0;
    }
    if (len === undefined) {
        len = t.length - start;
    }

    if (len > 1) {
        var left = start;
        var right = start + len - 1;
        var base = t[right];
        while (left <= right) {
            while (sortfunction(t[left], base) < 0 /*t[left] < base*/) {
                left++;
            }
            while (sortfunction(t[right], base) > 0 /*t[right] > base*/) {
                right--;
            }
            if (left <= right) {
                // swap
                var tmp = t[left];
                t[left] = t[right];
                t[right] = tmp;

                left++;
                right--;
            }
        }

        superFastSort(t, sortfunction, start, right + 1 - start);
        superFastSort(t, sortfunction, right + 1, len - right - 1);
    }
}

// var table = [17, 12, 6, 19, 23, 8, 5, 10];
// superFastSort(table, function(a, b){return a - b;});
// console.log(table);