Re^3: Hooks like Storable for Dumper?

Programmers expect a dump to reflect the underlying code structure and the dump they get would be just a convenient fiction.

You can’t help that, can you? Going around diddling innards according to a Data::Dumper reading is a bad idea anyway; I don’t think you should feel obligated to support this notion. What you want to do is support Data::Dumper-based serialisation; that’s another matter altogether.

Registering the Freezer/Toaster requires loading Data::Dumper – so regardless of whether a dump is ever called, just supporting Data::Dumper requires the overhead of loading it.

How so? You can always assign a value to $Data::Dumper::Freezer, whether the module is loaded or not.

sub f { warn };
$Data::Dumper::Freezer = 'f';
require Data::Dumper;
Data::Dumper::Dumper( bless \$_, 'main' );
__END__
Warning: something's wrong at - line 1.
[download]

The real problem I see is that multiple modules may want to use this hook, and they will probably all have a different idea of what the right value for $Data::Dumper::Freezer is.

You could try to be a little more cooperative by using something like this:

$Data::Dumper::Freezer = "DD_freezer" unless defined $Data::Dumper::Fr
+eezer;

*{; do { no strict 'refs'; \*{$Data::Dumper::Freezer} } } = sub {
    # serialisation code here
};
[download]

But that gives you no guarantee that everyone else will attempt to be similarly cooperative. :-/

Makeshifts last the longest.

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Re^4: Hooks like Storable for Dumper? by xdg (Monsignor) on Jan 03, 2006 at 15:29 UTC
The real problem I see is that multiple modules may want to use this hook, and they will probably all have a different idea of what the right value for $Data::Dumper::Freezer is. Good point. I misunderstood how `$Data::Dumper::Freezer` worked. I thought you had to do something like this and it registered per package: `package Foo; use Data::Dumper; Data::Dumper->Freezer( "__FREEZE" ); # Incorrect! sub __FREEZE { # custom class dump here }` [download] It looks like it's just a global, which is even worse. (Unless you want to use Data::Dumper objects, which can have a per D::D object freezer, but that's doesn't help either.) As the discussion below suggests, I think `Data::Dumper::Streamer` comes closest with its `FreezeClass` handlers. -xdg Code written by xdg and posted on PerlMonks is public domain. It is provided as is with no warranties, express or implied, of any kind. Posted code may not have been tested. Use of posted code is at your own risk.	[reply] [d/l] [select]

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Re^4: Hooks like Storable for Dumper?
by xdg (Monsignor) on Jan 03, 2006 at 15:29 UTC

The real problem I see is that multiple modules may want to use this hook, and they will probably all have a different idea of what the right value for $Data::Dumper::Freezer is.

Good point. I misunderstood how $Data::Dumper::Freezer worked. I thought you had to do something like this and it registered per package:

package Foo;

use Data::Dumper;
Data::Dumper->Freezer( "__FREEZE" );  # Incorrect!

sub __FREEZE {
  # custom class dump here
}
[download]

It looks like it's just a global, which is even worse. (Unless you want to use Data::Dumper objects, which can have a per D::D object freezer, but that's doesn't help either.)

As the discussion below suggests, I think Data::Dumper::Streamer comes closest with its FreezeClass handlers.

-xdg

Code written by xdg and posted on PerlMonks is public domain. It is provided as is with no warranties, express or implied, of any kind. Posted code may not have been tested. Use of posted code is at your own risk.

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