diff options
Diffstat (limited to 'lib/Exporter.pm')
| -rw-r--r-- | lib/Exporter.pm | 65 |
1 files changed, 62 insertions, 3 deletions
diff --git a/lib/Exporter.pm b/lib/Exporter.pm index 66459b8af0..3f42e407e0 100644 --- a/lib/Exporter.pm +++ b/lib/Exporter.pm @@ -108,7 +108,8 @@ sub export { last; } } elsif ($sym !~ s/^&// || !$exports{$sym}) { - warn qq["$sym" is not exported by the $pkg module]; + require Carp; + Carp::carp(qq["$sym" is not exported by the $pkg module]); $oops++; } } @@ -137,8 +138,9 @@ sub export { if (@failed) { @failed = $pkg->export_fail(@failed); foreach $sym (@failed) { - warn qq["$sym" is not implemented by the $pkg module ], - "on this architecture"; + require Carp; + Carp::carp(qq["$sym" is not implemented by the $pkg module ], + "on this architecture"); } if (@failed) { require Carp; @@ -165,6 +167,15 @@ sub export { } } +sub export_to_level +{ + my $pkg = shift; + my ($level, $junk) = (shift, shift); # need to get rid of first arg + # we know it already. + my $callpkg = caller($level); + $pkg->export($callpkg, @_); +} + sub import { my $pkg = shift; my $callpkg = caller($ExportLevel); @@ -172,6 +183,7 @@ sub import { } + # Utility functions sub _push_tags { @@ -346,6 +358,53 @@ You can say C<BEGIN { $Exporter::Verbose=1 }> to see how the specifications are being processed and what is actually being imported into modules. +=head2 Exporting without using Export's import method + +Exporter has a special method, 'export_to_level' which is used in situations +where you can't directly call Export's import method. The export_to_level +method looks like: + +MyPackage->export_to_level($where_to_export, @what_to_export); + +where $where_to_export is an integer telling how far up the calling stack +to export your symbols, and @what_to_export is an array telling what +symbols *to* export (usually this is @_). + +For example, suppose that you have a module, A, which already has an +import function: + +package A; + +@ISA = qw(Exporter); +@EXPORT_OK = qw ($b); + +sub import +{ + $A::b = 1; # not a very useful import method +} + +and you want to Export symbol $A::b back to the module that called +package A. Since Exporter relies on the import method to work, via +inheritance, as it stands Exporter::import() will never get called. +Instead, say the following: + +package A; +@ISA = qw(Exporter); +@EXPORT_OK = qw ($b); + +sub import +{ + $A::b = 1; + A->export_to_level(1, @_); +} + +This will export the symbols one level 'above' the current package - ie: to +the program or module that used package A. + +Note: Be careful not to modify '@_' at all before you call export_to_level +- or people using your package will get very unexplained results! + + =head2 Module Version Checking The Exporter module will convert an attempt to import a number from a |