salva has asked for the wisdom of the Perl Monks concerning the following question:

Are there any good alternatives to Storable?

I need a serializer that can be instructed to replace some inner objects on the fly just before serializing then using a callback.

Storable has the STORABLE_freeze and STORABLE_thaw hooks but they are not per-object but per-class and besides that, they are methods of the class, not something that can be controlled by the code calling the serializer.

I was thinking of extending Storable, but frankly, its code its one of the worst examples of code rot I have ever seen and so, my question.

update: an example of what I need to do: 

my $data = serialize $tree, sub {
    my $obj = shift;
    if (check_some_condition($obj)) {
        return replace($obj)
    }
    return (); # serialize $obj as is
};

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Re: Storable alternatives
by tobyink (Canon) on May 17, 2013 at 13:59 UTC

    Sereal may be worth looking at. It doesn't have the hooks you're looking for, but based on my experience (porting Sereal::Encoder to PHP) it's relatively clean code if you want to extend it. (Albeit mostly XS.)

    It's also an actively developed framework and format, so you might have a good chance of getting your extensions adopted into the Sereal::{Encoder,Decoder} modules.

    package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name
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Re: Storable alternatives
by BrowserUk (Patriarch) on May 17, 2013 at 17:09 UTC

    If you decide to implement this yourself, you could do worse than use Clone as a starting point.

    With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
    Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
    "Science is about questioning the status quo. Questioning authority".
    In the absence of evidence, opinion is indistinguishable from prejudice.
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Re: Storable alternatives
by BillKSmith (Monsignor) on May 17, 2013 at 14:30 UTC

    The book "Intermediate Perl" has a rather long section on "Marshalling Data". It may help.

    Bill
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Re: Storable alternatives
by vsespb (Chaplain) on May 17, 2013 at 13:06 UTC
    What's stopping you from using procedural programming? 
    sub my_serialize {
    my $obj = shift;
    if (check_some_condition($obj)) {
        return freeze replace($obj)
    }
    return freeze $obj; # serialize $obj as is
};

my $data = my_serialize($tree)

    [download]
[reply]
[d/l]
      $tree may be an arbitrarily complex structure and I just want to replace some of the objects inside at serialization time.

      Your code can only be used to replace the top object.

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[d/l]
        Your code can only be used to replace the top object.
        Not quite understand. replace() sub here _can_ replace just _some_ of the inner objects of $tree
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Re: Storable alternatives
by locked_user sundialsvc4 (Abbot) on May 17, 2013 at 13:22 UTC

    Storable has produced some very interesting .. ahem .. problems for me that I never quite figured out.   I would freeze something, then thaw it again, and it came out corrupted.   Some did, some didn’t.   I don’t know if it was the Perl version, the system (an AS/400), or what.   But what I did find, that worked out equally well for me (given that storage-space was not a concern), was good ol’ JSON, stored in a memo-field in a database.   (Which had the added bonus of being human-readable.)   I’ve worked with plenty of legacy systems since then which seem to have no problems with it, but I’ve become gun-shy.

      Unfortunately, JSON can only represent a subset of the data structures that can be created in Perl. In example, it can not represent self-referencing data structures.
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