Beefy Boxes and Bandwidth Generously Provided by pair Networks
P is for Practical

Re^3: sharing symbols

by ferreira (Chaplain)
on Apr 13, 2007 at 19:42 UTC ( #609994=note: print w/replies, xml ) Need Help??

in reply to Re^2: sharing symbols
in thread sharing symbols

Oh no, I see you only support only upper case letters only names (which would exclude @GLOBAL_SYMBOLS). Which seems too restrictive to my taste.

Don't go down on me that fast. This restriction can be lifted very easily and that's why I kept is_constant separated from push_constants. If the role of is_constant is taken by a subroutine ref, the rest is generic enough.

Here an implementation of that generic module whose idea you cherished for a moment:

package Exporter::All; use strict; use warnings; use base qw(Exporter); our $VERSION = '0.01'; use Carp qw(carp); # these are not package symbols, but Perl artifacts my @GLOBAL_SYMBOLS = qw(ISA EXPORT EXPORT_OK EXPORT_TAGS BEGIN ); my %EXCLUDE_LIST; @EXCLUDE_LIST{@GLOBAL_SYMBOLS} = (1) x @GLOBAL_SYMBOLS; sub export_all { my $self = shift; my %args = @_; my $package = $args{package} || $self; while (my ($k, $v) = each %args) { if ($k eq 'export') { unless ( $v eq 'CODE' ) { carp "should be a subroutine ref"; next; } my $export_ref = do { no strict 'refs'; \@{ "${package}::E +XPORT" } }; push @$export_ref, _select_symbols($package, $v); } else { carp "unknown parameter '$k'"; } } } sub _select_symbols { my $package = shift; my $predicate = shift; # iterate the package stash my @keys = do { no strict 'refs'; keys %{$package . '::'} }; return grep { !$EXCLUDE_LIST{$_} && do { no strict 'refs'; defined *{"${package}::${_ +}"}{CODE} } # has CODE slot && $predicate->() } @keys } 1; __END__ =head1 NAME Exporter::All - Export a bunch of symbols easily =head1 SYNOPSIS In the code you have symbols to export package MyModule; use base qw(Export::All); MyModule->export_all( export => sub { /^my_/ } ); # these are automatically exported sub my_home { } sub my_office { } In user's code use MyModule; # imports all my_ functions
And then applying it to the original request of the OP:
package MyConstants; use base qw(Exporter::All); # must be found in @INC our @EXPORT; __PACKAGE__->export_all( export => qr/^[A-Z]+$/ ); our $VERSION = 3; # it doesn't export this! use constant FOO => 1; use constant BAR => 2; use constant BOO => 3; 1;
The user's code just says
use MyConstants;
to import the constants into the current namespace.

BTW I have not worried with @GLOBAL_SYMBOLS because it didn't match /^[A-Z]+$/ which does not accept underlines. It was an oversight, but, because of this, it was not a problem.

BTW you were right about using a hash. The grep was only for a quick-and-dirty solution.

Log In?

What's my password?
Create A New User
Domain Nodelet?
Node Status?
node history
Node Type: note [id://609994]
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others having an uproarious good time at the Monastery: (10)
As of 2023-02-01 13:17 GMT
Find Nodes?
    Voting Booth?
    I prefer not to run the latest version of Perl because:

    Results (3 votes). Check out past polls.