 |  |
12.8. Importing with Exporter
Earlier we skipped over that "and now magic happens" part where the import routine (defined by the module author) is supposed to take File::Basename::fileparse and somehow alias it into the caller's package so it's callable as fileparse.
Perl provides a lot of introspection capabilities. Specifically, you can look at the symbol table (where all subroutines and most variables are named), see what is defined, and alter those definitions. You saw a bit of that back in the AUTOLOAD mechanism earlier. In fact, as the author of File::Basename, if you simply want to force filename, basename, and fileparse from the current package into the main package, you can write import like this:
sub import {
no strict 'refs';
for (qw(filename basename fileparse)) {
*{"main::$_"} = \&$_;
}
}Boy, is that cryptic! And limited. What if you didn't want fileparse? What if you invoked use in a package other than main?
Thankfully, there's a standard import that's available in the Exporter module. As the module author, all you do is add:
use Exporter; our @ISA = qw(Exporter);
Now the import call to the package will inherit upward to the Exporter class, providing an import routine that knows how to take a list of subroutines[71] and export them to the caller's package.
[71]And variables, although far less common, and arguably the wrong thing to do.
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| 12.7. Setting the Path at the Right Time |  | 12.9. @EXPORT and @EXPORT_OK |
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