Beefy Boxes and Bandwidth Generously Provided by pair Networks
Keep It Simple, Stupid
 
PerlMonks  

Re^2: How to export a package sitting lower in a module?

by HelenCr (Monk)
on Apr 22, 2013 at 15:26 UTC ( #1029907=note: print w/ replies, xml ) Need Help??


in reply to Re: How to export a package sitting lower in a module?
in thread How to export a package sitting lower in a module?

Corion and kennethk:

It works best if you put separate packages into separate files.

Sometimes (especially if you have an object-oriented project, with many little packages), it's not convenient to have each package in a speparate file.

So the solution is to add the export text (as Corion says) and then invoke import directly, i.e. pack_B->import.

Please note that this still doesn't work: the .pm module fails, complaining that the second @ISA is a bareword.

Main script:

use pack_A; pack_B->import; third();
The packages:
# Name of this file: pack_A.pm package pack_A; use strict; require Exporter; @ISA = qw {Exporter}; @EXPORT = qw {first second}; sub first { } sub second { } 1; #end package pack_A; package pack_B; use strict; require Exporter; @ISA = qw {Exporter}; @EXPORT = qw {third fourth}; sub third { } sub fourth { } 1; #end package pack_B; #end of file pack_A.pm


Comment on Re^2: How to export a package sitting lower in a module?
Select or Download Code
Re^3: How to export a package sitting lower in a module?
by kennethk (Monsignor) on Apr 22, 2013 at 15:38 UTC
    Sometimes (especially if you have an object-oriented project, with many little packages), it's not convenient to have each package in a speparate file.
    If you are doing OO programming in Perl, you don't need to import anything. Using packages as libraries and exporting subroutines into a user space is actually a direct contradiction with a rigid OO model.
    Please note that this still doesn't work: the .pm module fails, complaining that the second @ISA is a bareword.
    That's because you're violating strict. Try our:
    package pack_B; use strict; require Exporter; our @ISA = qw {Exporter}; our @EXPORT = qw {third fourth}; sub third { } sub fourth { } 1;

    #11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.

      Thank you, kennethk. That works (provided that you use "our @ISA" and "our @EXPORT" both in the first (pack_A) and the second (pack_B) packages).

      Many thanks - Helen

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://1029907]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others romping around the Monastery: (19)
As of 2014-07-11 16:24 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    When choosing user names for websites, I prefer to use:








    Results (232 votes), past polls