Re: what is $self->verbose

[Michael Fowler]

On Thu, Oct 10, 2002 at 08:27:27PM +0200, Jenda Krynicky wrote:
> It's the reference that's blessed.

It's the referent that's blessed.

For example:

    #!/usr/bin/perl -w

    use strict;

    my $s    = 10;
    my $obj1 = \$s;
    bless($obj1, "Foo");


    $obj1->foo();    # prints "I am foo()"
    
    my $obj2 = \$s;
    $obj2->foo();    # prints "I am foo()"
    
    $s = "foo";
    
    my $obj3 = \$s;
    $obj3->foo();    # prints "I am foo()"


    package Foo;
    sub foo { print "I am foo()\n" }


> So to sum this up. The "magic" is NOT attached to the data referenced 
> nor to the variable itself, but to the reference.

The magic is attached to the variable referenced in the first argument in
the call to bless().  bless() simply returns a reference to that variable.


This can be further shown with Devel::Peek, a module for taking a look at
the internals of Perl variables:

    #!/usr/bin/perl -w

    use Devel::Peek;
    use strict;

    my $s   = 10;
    my $obj = \$s;
    bless($obj, "Foo");
    
    Dump($s);


This prints:

    SV = PVMG(0x8112ef0) at 0x8100904
      REFCNT = 2
      FLAGS = (PADBUSY,PADMY,OBJECT,IOK,pIOK)
      IV = 10
      NV = 10
      PV = 0
      STASH = 0x80f61c0     "Foo"

Notice the STASH element at the end.


Michael
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