>In one of my apps I just found and fixed a subtle edge-case bug caused by short-circuiting of logical operators. With my coding style I'm not usually vulnerable to it so it was interesting to be reminded of this feature of VFP.

Whoever needs the reminder... it's been drilled into me that any compiler will shortcircuit your logicals, period. And I take that into account whenever I'm coding. I've seen a few experienced guys do things like this

do case
   case not .FirstProcessGoesWell()
   case not .SecondProcessGoesWell()
...
   case not .LastProcessGoesWell()
   otherwise
      oMsg.Message("all is well")
endcase

...which is, for me, perhaps the neatest packaging of multiphase batch process, which needs to be abandoned on first critical error. Can't remember whom I first saw doing this, perhaps the Feltmans or someone around the ComCodebook project. This is shortcircuiting by design.

However, I've found a case where I'd expect shortcircuiting to work, but it doesn't. It's the evl() and nvl() functions, where both parameters are evaluated, regardless of what the first one returns. So if you try

xx=evl(call1(), call2())

call2 will be called no matter what call1 does. This is kind of counterintuitive, because the equivalent construct with iif() will not have this side effect.