Re: Pure perl lexical sub import

Another option using two packages (inspired by Re^8: In praise of Perl's object system. (OO namespaces))

use v5.36;

package Foo::Internal {
    use Scalar::Util 'looks_like_number';

    sub check_it ($self, $num) {
        say 'Hoorah!' if looks_like_number($num);
    }   
}

package Foo {
    sub new ($class) {
        bless {} => $class;
    }   

    no warnings 'once';
    *check_it = \&Foo::Internal::check_it; 
}

my $foo = Foo->new;
$foo->check_it(42);
$foo->looks_like_number(42);
[download]

Then

% perl internal.pl
Hoorah!
Can't locate object method "looks_like_number" via package "Foo" at in
+ternal.pl line 22.
[download]

Comment on Re: Pure perl lexical sub import Select or Download Code

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Re^2: Pure perl lexical sub import by NERDVANA (Priest) on Dec 22, 2024 at 20:01 UTC
So you mean basically have a scope where they're imported be a different package than what eventually holds the object methods, by copying out the functions into that other package? I suppose it works, but I'm having trouble imagining how I would structure things so that it is less ugly than just calling the external function by its full name in the intended package.	[reply]
Re^3: Pure perl lexical sub import by Arunbear (Prior) on Dec 23, 2024 at 12:39 UTC
There'd be one package which is your actual clean namespace meant for end users, and another package containing the implementation details. It only looks ugly because I was tired and didn't use Exporter. So with Exporter it would be like this :::::::::::::: Foo/Internal.pm :::::::::::::: use v5.36; package Foo::Internal { use Exporter 'import'; our @EXPORT = qw[check_it]; use Scalar::Util 'looks_like_number'; sub check_it ($self, $num) { say 'Hoorah!' if looks_like_number($num); } } 1; :::::::::::::: Foo.pm :::::::::::::: use v5.36; package Foo { use Foo::Internal; sub new ($class) { bless {} => $class; } } 1; :::::::::::::: clean.pl :::::::::::::: use v5.36; use Foo; my $foo = Foo->new; $foo->check_it(42); $foo->looks_like_number(42); [download]	[reply] [d/l]