in reply to Re^2: RFC: Simulating Python's @decorators in Perl with Attributes
in thread RFC: Simulating Python's @decorators in Perl with Attributes

Sorry, the verbose syntax example I gave was wrong. It would actually be like this: 
#!/usr/bin/perl 
use strict;
use warnings;

package Foo::Sorted;
use Attribute::Handlers;

sub Sorted :ATTR {
  print "all sorted"
}

package main;

my Foo::Sorted $tst :Sorted;

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Re^4: RFC: Simulating Python's @decorators in Perl with Attributes
by LanX (Saint) on Jun 01, 2013 at 14:18 UTC
    But if you worry about name collision in UNIVERSAL (which isn't my biggest concern) why don't you just import the attribute Sorted into the current package?

    Cheers Rolf

    ( addicted to the Perl Programming Language)

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[d/l]
      Importing the attribute does not seem to work: 
      # Foo.pm
package Foo;
use strict;
use Attribute::Handlers;
use Exporter 'import';

our @EXPORT = qw/Sorted/;

sub Sorted :ATTR {
  print "all sorted"
}

1;

# attr.pl
#!/usr/bin/perl 
use strict;
use warnings;

use Foo;

my Foo $tst1 :Sorted;
my $tst2 :Sorted;
print "done\n";

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      It dies with 
      Invalid SCALAR attribute: Sorted at /home/arun/attr.pl line 8.

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[d/l]
[select]
        yep, tried to analyze Attribute::Handlers but no time to dig into details.

        in the meantime, here a hack that works: (plz ignore, see UPDATE)

        
package Foo;
use strict;
use Attribute::Handlers;

sub import {

  my $pkg = (caller)[0];
  
  eval <<"_code_";
 sub ${pkg}::Sorted :ATTR {
    print "all sorted"
 }
_code_
  
}

1;

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        #!/usr/bin/perl 
use strict;
use warnings;
use Foo;

$\="\n";
 
my $tst2 :Sorted;
print "done\n"

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        Beside of this:

        I think attributes could be monkey patched to check a dedicated package like 'UNIVERSAL::attributes" for global attributes.

        Cheers Rolf

        ( addicted to the Perl Programming Language)

        UPDATE

        less hacky, more stable!

        package Foo;
use strict;
use Attribute::Handlers;

sub import {
  my $src_pkg=__PACKAGE__;
  my $dest_pkg = (caller)[0];
  
  my $import = "sub ${dest_pkg}::Sorted :ATTR { goto \&${src_pkg}::Sor
+ted }";
  eval $import;
  
}

sub Sorted {
  print "all sorted"
}
1;

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        the essential problem is that :ATTR stores the combination of package and coderef for every new attribute to be able to identify them later via findsym().

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