our $VERSION = '1.001001'; # 1.1.1
-my %importers;
-
-sub _importer {
+sub _prelude {
my $target = shift;
- \($importers{$target} ||= eval qq{
- package $target;
- sub { my \$m = splice \@_, 1, 1; shift->\$m(\@_) };
- } or die "Couldn't build importer for $target: $@")
+ my ($package, $file, $line)
+ = $target =~ /[^0-9]/ ? ($target) : caller($target + 2);
+ qq{package $package;\n}
+ . ($file ? "#line $line \"$file\"\n" : '')
+}
+
+sub _make_action {
+ my ($action, $target) = @_;
+ eval _prelude($target).qq{sub { shift->$action(\@_) }}
+ or die "Failed to build action sub to ${action} for ${target}: $@";
}
-
sub import::into {
my ($class, $target, @args) = @_;
- $class->${_importer($target)}(import => @args);
+ _make_action(import => $target)->($class, @args);
}
sub unimport::out_of {
my ($class, $target, @args) = @_;
- $class->${_importer($target)}(unimport => @args);
+ _make_action(unimport => $target)->($class, @args);
}
1;
use Thing1 ();
use Thing2 ();
+ use Thing3 ();
sub import {
my $target = caller;
Thing1->import::into($target);
Thing2->import::into($target, qw(import arguments));
+ Thing3->import::into(1); # import to level
}
Note: you don't need to do anything more clever than this provided you
package (and in fact on any object as well, although it's rarer that you'd
want to do that).
+If you provide C<import::into> with an integer instead of a package name, it
+will be used as the number of stack frames to skip to find where to export to.
+This has the advantage of preserving the apparent filename and line number
+being exported to, which some modules (L<autodie>, L<strictures>) check.
+
Finally, we also provide an C<unimport::out_of> to allow the exporting of the
effect of C<no>:
these approaches alone on something like L<Moose> or L<Moo> that's both
an exporter and a pragma.
-So, the complete solution is:
+So, a solution for that is:
my $sub = eval "package $target; sub { shift->import(\@_) }";
$sub->($thing, @import_args);
effect, and from the right package for caller checking to work - and so
behaves correctly for all types of exporter, for pragmas, and for hybrids.
+Additionally, some import routines check the filename they are being imported
+to. This can be dealt with by generating a L<#line directive|perlsyn/Plain
+Old Comments (Not!)> in the eval, which will change what C<caller> reports for
+the filename when called in the importer. The filename and line number to use
+in the directive then need to be fetched using C<caller>:
+
+ my ($target, $file, $line) = caller(1);
+ my $sub = eval qq{
+ package $target;
+ #line $line "$file"
+ sub { shift->import(\@_) }
+ };
+ $sub->($thing, @import_args);
+
Remembering all this, however, is excessively irritating. So I wrote a module
so I didn't have to anymore. Loading L<Import::Into> creates a global method
C<import::into> which you can call on any package to import it into another
=head1 CONTRIBUTORS
-None yet - maybe this software is perfect! (ahahahahahahahahaha)
+haarg - Graham Knop (cpan:HAARG) <haarg@haarg.org>
=head1 COPYRIGHT