Find the max slice of an array

gistfile1.txt

function sum(a,b){
    return a+b;
}

Array.prototype.min = function(){
    return Math.min.apply(null, this);
}

function maxSlice(arr){
    //Are there any negative numbers?  If not, the entire array is the greatest segment.
    if(arr.min() >= 0) return arr;

    //Is array length 1?  Just return
    if(arr.length == 1) return arr;

    //Find the entire sum
    var total = arr.reduce(sum);

    //Find the min index
    var mindex = arr.indexOf(arr.min());

    //If mindex at the end
    if(mindex == arr.length - 1) return maxSlice(arr.slice(0, -1));

    //If mindex at beginning
    if(mindex == 0) return maxSlice(arr.slice(1));

    //Split the array into two chunks
    l = maxSlice(arr.slice(0,mindex));
    lsum = l.reduce(sum);
    r = maxSlice(arr.slice(mindex+1));
    rsum = r.reduce(sum);

    //Return the greatest of the total or the chunks before / after the min
    if(total > lsum && total > rsum){
        return maxSlice(arr);
    } else {
        return (rsum > lsum) ? r : l;
    }
}

print(maxSlice([1, -3, 4, -2, 2]));
print(maxSlice([2, 3, 1, -5, 2]));
print(maxSlice([-23, -14, 4, 3, 2, -21, 14, -32, 40]));
print(maxSlice([-17, 14, 21, 2, -38, 22, 8, 7, 9, -38]));
print(maxSlice([-100, -200, 50, -50, 23, 22, 14, 1]));