bliako:

I'm pretty sure I understand what you're saying, but I'm not seeing what the problem is.

If you're just talking about subroutines in packages, then calling xyz() while you're in X::Y::Z won't accidentally call ::xyz() in the event that X::Y::Z::xyz() isn't defined. Instead you'll get an error about the missing subroutine:

$ cat pm_1232441.pl
use strict;
use warnings;

sub xyz { print "I'm ::xyz()\n"; }

{
    package FOO;
    sub xyz { print "I'm FOO::xyz()\n"; }

    sub abc {
        print "I'm FOO::abc()\n";
        xyz();
    }
}

{
    package BAR;

    sub abc {
        print "I'm BAR::abc()\n";
        xyz();
    }
}

xyz();
FOO::xyz();
FOO::abc();
BAR::abc();


Roboticus@Waubli ~
$ perl pm_1232441.pl
I'm ::xyz()
I'm FOO::xyz()
I'm FOO::abc()
I'm FOO::xyz()
I'm BAR::abc()
Undefined subroutine &BAR::xyz called at pm_1232441.pl line 21.
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If you're talking about object-oriented programming and you're using inheritance, then if someone overrides your xyz() you'd want to let it get called. Calling a specific implementation of an xyz() is usually an error because the wrong specialization won't know about any potential extra constraints on your object.

...roboticus

When your only tool is a hammer, all problems look like your thumb.