----- Original Message -----
From: "L. Neil Johnson" <[EMAIL PROTECTED]>
> I was initially misled by PERL in a Nutshell which
> says, under Namespaces and Packages, "If the package name is null, the
main
> package is assumed. For example, $var and $::var are the same as
> $main::var" (p. 160). After more reading and testing, it was determined
> that $var really _must_ be qualified as $::var to be seen in the module.
"Perl in a Nutshell" is quite correct here, I think. If the module does not
have a package name (which is rarely the case) then $var, $::var, and
$main::var are all the same thing.
D:\pscrpt>type trial.pm
sub double_it { return $var * 2}
1;
D:\pscrpt>type try.pl
use warnings;
use trial;
$var = 17;
$var++;
$z = double_it();
print $z, "\n";
D:\pscrpt>perl try.pl
36
D:\pscrpt>
I think it's only if trial.pm had a package name (as it normally would) that
'double_it' would have to be coded as either:
sub double_it { return $::var * 2}
or:
sub double_it { return $main::var * 2}
> Since the qualifier expands these short variable names, and some of the
> lines of code are long as is, I turned away from qualified names. Right
> now, whenever the definitions change in main::, I simply cut and paste
them
> into the module, and all works well. But there are four more big data
> arrays that are in development, and I'm tired of cutting and pasting. (I
> keep thinking about C header files and #define statements...)
>
> Question: What's the best way to handle this situation? Can I export
those
> offsets from main:: and "use" them in the module? Or is there some pragma
> that can be used to generate compile-time constants with global
visibility?
> Any suggestion would be appreciated.
Your reference to "#define statements" and "constants" makes me wonder
whether you might want to make use of the constant pragma (see perldoc
constant), but since I can't quite get a picture of the precise scenario, I
can't be sure :-)
Maybe your question is perfectly clear to someone else ..... otherwise you
might have to provide a simple little demo module and script to illustrate
the problem.
Cheers,
Rob
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