I'm having some dramas with understanding the referencing of enums from 'external' files. I think it's a combination of using the enum module and how scoping works in 'library' files... but I haven't been able to get my head 'round it...

I have a single, simple, 'library file' called 'slib.pl' that contains: 

package slib;

use enum qw(SM_UNK_REC
            SM_HDR_REC
            SM_TTL_REC);

   %SM_REC = ( SM_UNK_REC, "UNK",
               SM_HDR_REC, "HDR",
               SM_TTL_REC, "TTL" );

[...]

sub ABC {
   my ($type) = @_;

   if ($type == SM_HDR_REC) {
      [...]

   } elsif ($type == SM_TTL_REC) {
      [...]
}

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Now, this all works quite happily for subs in the library - the enums are within the same physical file so they will be visible in the file's name space.

However, I'm having trouble 'seeing' the enums when I try to use a sub in the library from another program. For example I might have a program 'test.pl' like: 

require 'slib.pl';

[...]

$stat = &slib::ABC(SM_HDR_REC);

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...and the SM_HDR_REC isn't translated properly. Initially, this makes sense, as there's nothing called 'SM_HDR_REC' in test.pl... even though I've 'require'ed the file that *does* include it.

So I try: 

$stat = &slib::ABC($slib::SM_HDR_REC);

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...and it still isn't seen. Finally, I try: 

$stat = &slib::ABC(&slib::SM_HDR_REC);

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...and it works. ...but I don't understand why the $slib::SM_HDR_REC is wrong. I thought the '&' was only for 'executing' subs and the '$' was used to 'reference' the location where some value is stored.

What can I do about seeing why the '$' doesn't work like I think it should? More simply, is there a better way to do what I'm trying to do, that is be able to use a symbolic name for a piece of data in both the library file AND programs that call the library file?

I'm using ActiveState Perl 5.6.1/Win98 and Perl 5.8.?/WinXP SP2.

Thanks for any pointers.

John

In reply to Problems with the enum Module and File Scoping by ozboomer

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