Data::YAML - Easy YAML serialisation of Perl data structures

This document describes Data::YAML version 0.0.6

In the spirit of YAML::Tiny, Data::YAML::Reader and Data::YAML::Writer provide lightweight, dependency-free YAML handling. While YAML::Tiny is designed principally for working with configuration files Data::YAML concentrates on the transparent round- tripping of YAML serialized Perl data structures.

As an example of why this distinction matters consider that YAML::Tiny doesn't handle hashes with keys containing non-printable characters. This is fine for configuration files but likely to cause problems when handling arbitrary Perl data structures. Data::YAML handles exotic hash keys correctly.

The syntax accepted by Data::YAML is a subset of YAML. Specifically it is the same subset of YAML that Data::YAML::Writer produces. See Data::YAML for more information.

Although YAML appears to be a simple language the entire YAML specification is huge. Data::YAML implements a small subset of the complete syntax trading completeness for compactness and simplicity. This restricted syntax is known (to me at least) as 'YAMLish'.

These examples demonstrates the full range of supported syntax.

All YAML documents must begin with '---' and end with a line containing '...'.

    --- Simple scalar
    ...

Unprintable characters are represented using standard escapes in double quoted strings.

    --- "\t\x01\x02\n"
    ...

Array and hashes are represented thusly

    ---
      - "This"
      - "is"
      - "an"
      - "array"
    ...

    ---
      This: is
      a: hash
    ...

Structures may nest arbitrarily

    ---
      -
        name: 'Hash one'
        value: 1
      -
        name: 'Hash two'
        value: 2
    ...

Undef is a tilde

    --- ~
    ...

Use Data::YAML may be used any time you need to freeze and thaw Perl data structures into a human readable format. The output from Data::YAML::Writer should be readable by any YAML parser.

Data::YAML was originally written to allow machine-readable diagnostic information to be passed from test scripts to TAP::Harness. That means that if you're writing a testing system that needs to output TAP version 13 or later syntax you might find Data::YAML useful.

Read more about TAP and YAMLish here: http://testanything.org/wiki

No bugs have been reported.

Please report any bugs or feature requests to data-yaml@rt.cpan.org, or through the web interface at http://rt.cpan.org.

Andy Armstrong <andy@hexten.net>

Copyright (c) 2007, Andy Armstrong <andy@hexten.net>. All rights reserved.

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See perlartistic.

BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR, OR CORRECTION.

IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.