--- Jon Cassorla <[EMAIL PROTECTED]> wrote:
>
> There are many ways to do this. Here is just one example using a
> closure.
>
> package Remember;
>
> # this is a closure
> {
> my $savedData = 0; # only accessible within this scope; side
> effect is that
> # it stays around as long as the module since
> the following
> # method needs it
>
> sub rememberData
> {
> my $class = shift;
> $savedData = shift if @_; # update with new value if given
> return $savedData; # return current value
> }
> }
>
> 1;
>
>
> Here is a test program to validate that the data in $savedData stays
> around.
Actually, you really don't want to try to lexically scope a subroutine like that
(because you
can't -- well, there is a way, but it involves messing with symbol tables and that's
usually not a
good idea).
Your code can easily result in mysterious "Variable $foo will not stay shared" errors.
Here's a
sample program to show why this is bad practice (even though it looks good):
#!/usr/bin/perl -w
use strict;
first( "Ovid" );
second();
first( "foo" );
sub first {
my $argument = shift;
second();
sub second {
print "$argument\n";
}
}
That will print "Ovid" three times and warn you that the variable $argument will not
stay shared.
Cheers,
Curtis "Ovid" Poe
=====
Senior Programmer
Onsite! Technology (http://www.onsitetech.com/)
"Ovid" on http://www.perlmonks.org/
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