On Wed, May 01, 2002 at 05:08:14PM -0400, Miko O'Sullivan wrote: > Damian said: > > The C<BETWEEN> block can't decide whether to execute until > > it knows whether the loop is going to iterate again. And it can't > > know *that* until it has evaluated the condition again. At which > > point, the $filename variable has the wrong value. :-( > > > > The example is a little contrived perhaps, but it might be a common > > problem. > > I don't think your example is contrived at all. It's just a situation > where a little education is all that's needed. The rule could be quite > simple: BETWEEN is run before every iteration except for the first > iteration. Any variables that you use in BETWEEN are for the iteration > that is about to run, not the iteration that just ran. Once people gt > that concept things become clear.
You know, I almost made a very similar reply. But I read through Damian's message a second time and changed my mind. C<BETWEEN> makes sense as a C<NEXT> minus C<LAST>. As a C<PRE> minus C<FIRST> it's less appealing. At the very least it begs a different name than "BETWEEN" (a name that implies it executes "between" each loop, not at the beginning of some). Hmmm... would C<LAST> not have the same problem as C<BETWEEN>? It also "can't decide whether to execute until it knows whether the loop is going to iterate again". Allison
