<!-- GENERATED by docs/sphinx/bin/20-reference (p5) from reference/bundled/PDL/IO/Storable.md. Do not edit. -->

```{index} single: PDL::IO::Storable
```

# PDL::IO::Storable

helper functions to make PDL usable with serialisation packages

## SYNOPSIS

```perl
use Storable;
use PDL::IO::Storable;
$hash = {
          'foo' => 42,
          'bar' => zeroes(23,45),
        };
store $hash, 'perlhash.dat';

use JSON::MaybeXS;
$encoder = JSON::MaybeXS->new(allow_tags => 1);
my $ndarray = xvals (5,2);
my $encoded_json = $encoder->encode ($ndarray);
my $decoded_ndarray = $encoder->decode ($encoded_json);
```

## DESCRIPTION

Serialisation packages such as `Storable`, `Sereal`, `JSON::MaybeXS`
and `CBOR::XS` implement
object persistence for Perl data structures that can
contain arbitrary Perl objects. This module implements the relevant methods to
be able to store and retrieve ndarrays via `Storable` as well as packages that support
the [Types::Serialiser](https://metacpan.org/pod/Types::Serialiser) protocol (currently [Sereal](https://metacpan.org/pod/Sereal), [CBOR::XS](https://metacpan.org/pod/CBOR::XS) and JSON packages).

Note that packages supporting the `Types::Serialiser` protocol need to have their
respective flags enabled so that the FREEZE and THAW callbacks are used.

Note also that while [JSON::MaybeXS](https://metacpan.org/pod/JSON::MaybeXS) is supported, if it has to
fall back to [JSON::PP](../../JSON/PP.md), it will fail. [JSON::XS](https://metacpan.org/pod/JSON::XS) treats the data
it gets back from `FREEZE` as items to encode, while [JSON::PP](../../JSON/PP.md)
treats the list it gets as strings already encoded. They are
fundamentally incompatible, so this module supports the JSON::XS
option.

Finally, [data flow](https://metacpan.org/pod/PDL::Dataflow) is not preserved.  If a data structure
containing ndarrays connected by data flow is serialised then this will need to be
explicitly reinstated on deserialisation.

## FUNCTIONS

### store

store an ndarray using [Storable](../../Storable.md)

```perl
$x = random 12,10;
$x->store('myfile');
```

### freeze

freeze an ndarray using [Storable](../../Storable.md)

```perl
$x = random 12,10;
$frozen = $x->freeze;
```

## AUTHOR

Copyright (C) 2013 Dima Kogan <dima@secretsauce.net>
Copyright (C) 2002 Christian Soeller <c.soeller@auckland.ac.nz>
All rights reserved. There is no warranty. You are allowed
to redistribute this software / documentation under certain
conditions. For details, see the file COPYING in the PDL
distribution. If this file is separated from the PDL distribution,
the copyright notice should be included in the file.