Re: Question re $obj->$action(@args) syntax

[kyle]

I don't think I understand your question. I tried this:

use strict;
use warnings;

use Data::Dumper;

my $obj = bless {}, 'Foo';
my $action = sub { print Dumper( \@_ ) };
$obj->$action( 'hello' );
__END__
$VAR1 = [
          bless( {}, 'Foo' ),
          'hello'
        ];

...and that works. Are you saying you want to do something like "$obj->sub { do_stuff(); etc(); }( @args );" so that you don't need an explicit $action? It seems that you're basically doing something like:

{
    @_ = ( $obj, @args );
    # rest of 'sub' goes here
}

"Inline" code doesn't need to be made into a sub. Am I misunderstanding your question?

[blazar]

I don't think I understand your question. I tried this:

# snip code

...and that works.

Of course!

Are you saying you want to do something like "$obj->sub { do_stuff(); etc(); }( @args );" so that you don't need an explicit $action?

Exactly, out of orthogonality considerations.

It seems that you're basically doing something like:

{
    @_ = ( $obj, @args );
    # rest of 'sub' goes here
}

"Inline" code doesn't need to be made into a sub. Am I misunderstanding your question?

Possibly so: I certainly don't understand your reply. Are you saying that you would expect the following to work as (I) intended?

use strict;
use warnings;

use Data::Dumper;

my $obj = bless {}, 'Foo';
$obj->{ print Dumper( \@_ ) }( 'hello' );

__END__

If so, then it doesn't because ->{ is interpreted as hash dereferencing:

$VAR1 = [];
Use of uninitialized value in subroutine entry at 605841.pl line 7.
Can't use string ("") as a subroutine ref while "strict refs" in use a
+t 605841.p
l line 7.

OTOH Anno and grinder completely addressed my question.

[kyle]

Are you saying that you would expect the following to work as (I) intended?

No, not at all. What I'm saying is that the code I wrote achieves the goal of removing the extra variable (i.e., there's no explicit $action code ref) while not achieving the goal of a "$obj->blah(@args)" style syntax. To be longer and more explicit:

use strict;
use warnings;

use Data::Dumper;

my $obj = bless {}, 'Foo';
my @args = ( 'hello' );
{
    @_ = ( $obj, @args );
    print Dumper( \@_ )
}
__END__
$VAR1 = [
          bless( {}, 'Foo' ),
          'hello'
        ];

The functional difference between this and what you're shooting for is (in addition to the gross syntax difference) that this one is taking copies in @_ instead of aliases.

So, perhaps a better short version of what I'm saying is, "if all you want to do is eliminate a variable, do this..." Sorry for the confusion.

[blazar]

No, not at all. What I'm saying is that the code I wrote achieves the goal of removing the extra variable (i.e., there's no explicit $action code ref) while not achieving the goal of a "$obj->blah(@args)" style syntax.

Oh, but that I knew. My question was clearly focusing on syntax, not semantics. It was a question "out of curiosity" after all...

So, perhaps a better short version of what I'm saying is, "if all you want to do is eliminate a variable, do this..." Sorry for the confusion.

Not at all, it's an instructive discussion anyway, for someone who could stumble upon it, I guess...