Monks,

Updated: Several typos and omissions fixed.

Here's a weird thing I don't understand. Can another more enlightened share his knowledge? I am working on a large set of scripts and have a 'Utilities' module for simple stuff that's used repeatedly across multiple packages. I wanted to put some sort routines in there, but got tripped up by the fact that the $a and $b used in sort routines are package globals, and these sort routines are used in packages different from the one they are defined in. So I thought, hey, simple answer: export $a and $b from 'Utilities' so the package globals are aliased. That didn't work. I checked and made sure that $a and $b in the Utilities package and the use-ing package were really aliases of e/o, and they were; I even printed out $a inside the sorting sub and the correct value was being printed.

What did turn out to work was exporting *a and *b. I don't understand why that worked and exporting $a/b didn't. Anybody got a clue as to why exporting $a/b doesn't work, but exporting the corresponding type globs does?

Here's some example code:

file1: main.pl 

#!/usr/bin/perl

use lib '.';
use Sorts;

$, = "\n";
print sort caseless ('a','s','d','f');

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file 2: Sorts.pm

version 1 -- b0rken, a/b not exported: 

use Exporter;
package Sorts;

use base 'Exporter';
@Sorts::EXPORT = qw(caseless);

sub caseless { lc $a cmp lc $b }

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version 2 -- still b0rken, $a/b exported: 
use Exporter;
package Sorts;

use base 'Exporter';
@Sorts::EXPORT = qw(caseless $a $b);

sub caseless { lc $a cmp lc $b }

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version 3 -- works!, *a/b exported: 
use Exporter;
package Sorts;

use base 'Exporter';
@Sorts::EXPORT = qw(caseless *a *b);

sub caseless { lc $a cmp lc $b }

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running main.pl with the first two versions of Sorts.pm produces: 
a
s
d
f

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but with the third version outputs: 
a
d
f
s

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--DrWhy

"If God had meant for us to think for ourselves he would have given us brains. Oh, wait..."

In reply to sort routines crossing package lines by DrWhy

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