Human Readable Binary Search

BinarySearch.cs

public class IntArray
{
    public static int BinarySearch(int[] items, int searchTerm)
    {
        return SearchRecursively(items, searchTerm, 0, items.Length - 1);
    }

    private static int SearchRecursively(int[] items, int searchTerm, int lowerIndex, int upperIndex)
    {
        var scannedAllItems = lowerIndex > upperIndex;
        if (scannedAllItems) return -1;

        var middleIndex = (lowerIndex + upperIndex) / 2;
        var middleItem = items[middleIndex];

        var isItemPresentAtMiddleIndex = items[middleIndex] == searchTerm;
        if (isItemPresentAtMiddleIndex) return middleIndex;

        var searchItemInLowerHalf = middleItem.CompareTo(searchTerm) > 0;
        if (searchItemInLowerHalf) return SearchRecursively(items, searchTerm, lowerIndex, middleIndex - 1);

        var searchItemInUpperHalf = middleItem.CompareTo(searchTerm) < 0;
        if (searchItemInUpperHalf) return SearchRecursively(items, searchTerm, middleIndex + 1, upperIndex);

        return -1;
    }
}