[tcltk-perl] RE: scalar($w->getOpenFile)

[Jeff H. <je...@ac...>]

>     my $mw = MainWindow->new;
>     my $label = $mw->Label(-text => "Hello")->pack;
>     if (my $file = $mw->getOpenFile) {
>         $label->configure(-text => "File [$file]");
	...
> and then hit "Cancel" to the dialog that pops up, then we 
> fill in the field with something like "File 
> [ARRAY(0x8141ad8)]".  Apparently tk_getOpenFile returns a 
> list instead of string, but this is not documented.  Since 

I have identified the source of this problem, and it has to
do with promiscuous object literal sharing in Tcl.  The
empty object (string rep "") is being converted to a list at
some point (perfectly valid, as you can still request the
string).  The problem is that when the literal "" object is
passed through to Perl, I check for tclListType first and
create an (empty) array.

My solution to this is to not create an array until the list
actually has length > 0.  This is all in SvFromTclObj, BTW.

My question is, should I create the alternate "empty" list
as newSV(0) (== undef), or newSVpvn("", 0) (== "" I think)?

BTW, the messageBox issue was the same - the literal "yes"
was being used as a boolean (which it validly is), and I was
checking for boolean type without regard to the fact that
the string rep of a boolean can be lots of things other than
0/1.  The solution there is to make sure that I only convert
booleans with no string rep to boolSVs.

Jeff