compile or run-time inheritance

[sh1tn]

Fellow Monks,

Please let me know - when does the inheritence occur in perl? And if it's by default compile time, is there a way to be inforced to happen at run-time?

[gellyfish]

Sure you can manipulate the inheritance at runtime - see for instance the second example in Re: Creating packages on the fly.

/J\

[adrianh]

Please let me know - when does the inheritence occur in perl? And if it's by default compile time, is there a way to be inforced to happen at run-time?

Well - compile/run time is a very fuzzy divide with Perl. But yes - you can change the inheritance structure of objects at run time (e.g. by tweaking the @ISA of a package.)

[ioannis]

You cannot have binding of methods before INIT because the type of invocant is determined at runtime. For example, when we bless a reference with bless {}, $string, this executes at runtime to assign the class type, which tells us which @ISA to examine.

[adrianh]

You cannot have binding of methods before INIT because the type of invocant is determined at runtime

I beg to differ :-)

#! /usr/bin/perl

use strict;
use warnings;

INIT {
    print "in INIT\n";
    print "out INIT\n";
}

BEGIN {
    print "in BEGIN\n";
    
    {   package Foo;
        sub new { bless {}, shift };
        sub foo { print "I'm a ", shift, "\n"};
    }
    
    Foo->new->foo;
    
    print "out BEGIN\n";
}

__END__
in BEGIN
I'm a Foo=HASH(0x181af90)
out BEGIN
in INIT
out INIT