VB6: Sorting algorithms (sort array, sorting arrays)

[Ellis Dee]

Not sure which one yet though, it seems like a toss up between Stability and Speed.

These are the parameters as it stands

Public Function SortArrayX(ByVal ArrayPtr As Long, SortFieldElement As Variant, Optional Descending As Boolean = False) as boolean

Merge sort is both stable and fast, plus it has the bonus of having no worst case; it's always fast. And as I discussed upthread, if you're going to include a Descending option, you pretty much have to use a stable algorithm. (There is just no relevance to the direction of an unstable sort; ascending and descending don't matter. Just change the direction you iterate the array after sorting.) I really can't see using any other algorithm if your going to create a one-stop sorting function. The code sprawl is annoying, but whaddya gonna do?

A generic UDT array sorter would be one of the most impressive things I could imagine in VB6, but I'm not sure of the utility of it. I have in the past used sorted UDT arrays, but as comfortable as I am with sorting code, even I didn't physically sort the UDT array. Instead, I built two-dimensional variant index arrays and sorted those. That's pretty much always going to be faster than sorting a UDT directly, even if you write a specific sorting function devoted to that particular UDT.