Exporter collision detection

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Did Exporter ever die or issue a warning when it clobbers existing symbols? I think it should

$ perl -MData::Dump::Streamer -MYAML -le ' Data::Dump::Streamer::Dump(
+ \*Dump ) '
$GLOB1 = \*::Dump;
*::Dump = sub {
            package YAML;
            use warnings;
            use strict 'refs';
            my $yaml = 'YAML'->new;
            $yaml->dumper_class($DumperClass) if $DumperClass;
            return $yaml->dumper_object->dump(@_);
          };

$ perl -MData::Dump::Streamer -mYAML -le ' Data::Dump::Streamer::Dump(
+ \*Dump ) '
$GLOB1 = \*::Dump;
*::Dump = sub {
            package Data::Dump::Streamer;
            use warnings;
            use strict 'refs';
            my $obj;
            if (blessed($_[0]) and blessed($_[0]) eq 'Data::Dump::Stre
+amer') {
              $obj = shift @_;
            }
            if (@_) {
              if (defined wantarray and not wantarray) {
                $obj ||= 'Data::Dump::Streamer'->new;
                $obj->_make_args(@_);
                return $obj;
              } else {
                $obj ||= 'Data::Dump::Streamer';
                return $obj->Data(@_)->Out;
              }
            } else {
              if ($obj) {
                return $obj->Out;
              } else {
                return 'Data::Dump::Streamer'->new;
              }
            }
          };

$ pmvers Data::Dump::Streamer YAML Exporter
Data::Dump::Streamer: 2.09
YAML: 0.70
Exporter: 5.63
[download]

Comment on Exporter collision detection Download Code

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Re: Exporter collision detection by ikegami (Patriarch) on Sep 28, 2009 at 15:17 UTC
It does. `>type ModA.pm package ModA; use Exporter qw( import ); @EXPORT = qw( foo ); sub foo { print __PACKAGE__, "\n" } 1; >type ModB.pm package ModB; use Exporter qw( import ); @EXPORT = qw( foo ); sub foo { print __PACKAGE__, "\n" } 1; >perl -we"use ModA; use ModB;" Subroutine main::foo redefined at c:/Progs/perl5101/lib/Exporter.pm li +ne 67. at -e line 1` [download] You need to turn on warnings if you want warnings.	[reply] [d/l]
Re^2: Exporter collision detection by Anonymous Monk on Sep 28, 2009 at 22:39 UTC
I don't think that is good enough because it doesn't always work $ perl -MData::Dump::Streamer -MYAML -wle 1 $ perl -MData::Dump::Streamer -MYAML -Wle 1 Use of uninitialized value $ENV{"B_UTILS_TRACE"} in addition (+) at /u +sr/local/lib/perl5/site_perl/5.10.1/x86_32-linux/B/Utils.pm line 72. Subroutine main::Dump redefined at /usr/local/lib/perl5/5.10.1/lib/Exp +orter.pm line 67. at -e line 0 Name "Exporter::CARP_NOT" used only once: possible typo at /usr/local/ +lib/perl5/5.10.1/lib/Carp/Heavy.pm line 304. Name "main::CARP_NOT" used only once: possible typo at /usr/local/lib/ +perl5/5.10.1/lib/Carp/Heavy.pm line 304. [download]	[reply] [d/l]