You find sorting algorithm in most programming languages, but you have to look hard for an implementation of common sorting algorithms in Visual FoxPro. Of course, Calvin Hsia has some on his blog, but otherthan that it's getting difficult. The most obvious reason is that Visual FoxPro supports sortingnatively for indexes as well as arrays.

Sorting mixed strings

If you have data like

INDEX ON STR(VAL(field)) + field TAG _Sort

Sorting with COLLATE

Virtually every application picks only one COLLATION sequence it uses all the time. The majority uses MACHINE,
followed by GENERAL, followed by country specific versions. However, sometimes you need to sort and search
data with a different order. For example, you might use MACHINE as the collate sequence, but in some cases
need to sort case-independent (that's just an example!).
When you create an index, Visual FoxPro uses the active COLLATE sequence or the one you specified with
the COLLATE clause. A little known fact is that Visual FoxPro always uses the COLLATE sequence that belong to
an index when Visual FoxPro searches or sorts using the index. This is true even when the application switched
to a different COLLATE sequence:
Create Cursor curTest (cName C(10))
Insert into curTest Values("Straße")
Set Collate To "GERMAN"
Index on cName Tag cName
Set Collate To "MACHINE"
? Seek("Strasse") && Prints .T.