"bgimeno" <bgimeno[at]persistencia[dot]org> wrote:
> I don't know if there is a special case in which a loop of  the variable
> "FooCounter" should remain unchanged.
> But what about a simple detector where the value of "FooCounter" from the
> #while(FooCounter cond) condition does not change when you reach the end of
> the loop?.

First of all, this would require special handling for conditional expressions to
detect the presence of such a construct during parsing.

Furthermore, consider this:

  #declare R = seed(4711);
  #declare Items = 0;
  #while (Items < 10000)
    #declare MyPos = SomeRandomPosition(R);
    #if (SomeCondition(MyPos))
      DoSomething(MyPos)
      #declare Items = Items + 1;
    #end
  #end

Obviously, the problem is more complicated than just checking whether the
variable value actually changes in each loop: Runtime checking won't do, you'd
need code analysis. Also note that the increment may be hidden nested deeply in
macros, so this is not a straightforward check for the existence of a "#declare
FooCounter = ..." somewhere inside the loop.

In my eyes it would be a kludge anyway, so why not heal the leg instead, and add
a proper #for loop - I'm sure we'd have that issue solved then.

(If POV 4 does indeed get a new SDL as promised, I'm quite sure it will not come
without a for loop anyway.)

Post a reply to this message