X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=p5sagit%2FImport-Into.git;a=blobdiff_plain;f=lib%2FImport%2FInto.pm;h=74b7358d9093c688b80beb9bb8d2c62745580e21;hp=59c861bdd848b9391fe0ccd466ce7fce455084b1;hb=995d8262bd1c7cc306aee068943efa7d205605c0;hpb=ac6d2081e8a5f1e5dbe0f95685080edaf40ca48b diff --git a/lib/Import/Into.pm b/lib/Import/Into.pm index 59c861b..74b7358 100644 --- a/lib/Import/Into.pm +++ b/lib/Import/Into.pm @@ -5,29 +5,28 @@ use warnings FATAL => 'all'; our $VERSION = '1.001001'; # 1.1.1 -my %importers; - -sub _importer { +sub _prelude { my $target = shift; - my ($package, $file, $line) = $target =~ /[^0-9]/ ? ($target) : caller($target + 1); - my $code = qq{package $package;\n} + my ($package, $file, $line) + = $target =~ /[^0-9]/ ? ($target) : caller($target + 2); + qq{package $package;\n} . ($file ? "#line $line \"$file\"\n" : '') - . 'sub { my $m = splice @_, 1, 1; shift->$m(@_) };'."\n"; - my $sub = \(eval $code - or die "Couldn't build importer for $package: $@"); - $importers{$target} = $sub - unless $file; - $sub; +} + +sub _make_action { + my ($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; @@ -44,11 +43,13 @@ Import::Into - import packages into other packages 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 @@ -74,6 +75,11 @@ C on it. This is a global method, and is callable on any package (and in fact on any object as well, although it's rarer that you'd want to do that). +If you provide C 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, L) check. + Finally, we also provide an C to allow the exporting of the effect of C: @@ -130,7 +136,7 @@ know if something's a pragma, and second that you can't use either of these approaches alone on something like L or L 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); @@ -139,6 +145,20 @@ which means that import is called from the right place for pragmas to take 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 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: + + 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 creates a global method C which you can call on any package to import it into another @@ -197,7 +217,7 @@ mst - Matt S. Trout (cpan:MSTROUT) =head1 CONTRIBUTORS -None yet - maybe this software is perfect! (ahahahahahahahahaha) +haarg - Graham Knop (cpan:HAARG) =head1 COPYRIGHT