NAME
Acme::CPANModules::DumpingDataForDebugging - Some modules and tips when
dumping data structures for debugging
VERSION
This document describes version 0.001 of
Acme::CPANModules::DumpingDataForDebugging (from Perl distribution
Acme-CPANModules-DumpingDataForDebugging), released on 2020-02-07.
DESCRIPTION
Some modules and tips when dumping data structures for debugging.
This list catalogs some of the modules you can you to dump your data
structures for debugging purposes, so the modules will be judged mostly
by the appropriateness of its output for human viewing (instead of other
criteria like speed, footprint, etc).
INCLUDED MODULES
* Data::Dumper
Everybody knows this module and it's core so sometimes it's the only
appropriate choice. However, the default setting is not really
optimized for viewing by human. I suggest you tweak these before
dumping your data:
* Set $Data::Dumper::Useqq to 1.
By default, Data::Dumper quotes strings using single-quotes and does
not quote things like "\n" and "\b" making it difficult to spot
special characters.
* Data::Dump
A data dumper that produces nicer Perl code output, with features
like vertical alignment of "=>" when dumping hashes, compacting
sequences like 1,2,3,4,5,6 to 1..6, compacting repeating characters
in string like "ccccccccccccccccccccc" to ("c" x 21), and so on.
It tries harder to produce Perl code that generates the original
data structure, particularly with circular references. But with
interlinked references like trees, Data::Dumper might be more
helpful in showing you which references get mentioned where. For
example this data:
$tree = {children=>[{children=>[{}]}, {children=>[]}]};
$tree->{children}[0]{parent}=$tree;
$tree->{children}[1]{parent}=$tree;
$tree->{children}[0]{children}[0]{parent} = $tree->{children}[0];
Data::Dump will produce:
do {
my $a = {
children => [
{ children => [{ parent => 'fix' }], parent => 'fix' },
{ children => [], parent => 'fix' },
],
};
$a->{children}[0]{children}[0]{parent} = $a->{children}[0];
$a->{children}[0]{parent} = $a;
$a->{children}[1]{parent} = $a;
$a;
}
while Data::Dumper will produce:
$VAR1 = {
'children' => [
{
'children' => [
{
'parent' => $VAR1->{'children'}[0]
}
],
'parent' => $VAR1
},
{
'parent' => $VAR1,
'children' => []
}
]
};
* Data::Dump::Color
A modification to Data::Dump which adds color (and color theme)
support, as well as other visual aids like depth and array
index/hash pair count indicator. It's usually my go-to module for
debugging.
* Data::Dumper::Compact
A relatively recent module by MSTROUT. I will need to use this more
to see if I really like the output, but so far I do.
* XXX
A nice little dumper module from the creator of YAML. Obviously, it
uses YAML output by default but it's configurable to dump in other
formats. For example:
PERL_XXX_DUMPER=Data::Dump::Color
It's main selling point is that the dumper function returns the
original arguments so the dumping can be done in various places in
code, making it more convenient. More (if not all) dumpers should do
this too.
* Data::Printer
Favorites among many Perl programmers, it sports colors, array index
indicator, as well as nice object dumper showing methods and
inheritance information. It's also very customizable. It uses its
own format though, and my preference for dumping is the Perl format
(with additional informations/hints as comments) so I've never used
it in my daily coding activities. I probably should though.
* JSON::Color
JSON is a limited format; it cannot represent many things that Perl
supports e.g. globs, circular references, or even ASCII NUL. But if
you are working only with JSON-able data, this JSON dumping module
adds color output.
* YAML::Tiny::Color
FAQ
What are ways to use this module?
Aside from reading it, you can install all the listed modules using
cpanmodules:
% cpanmodules ls-entries DumpingDataForDebugging | cpanm -n
or Acme::CM::Get:
% perl -MAcme::CM::Get=DumpingDataForDebugging -E'say $_->{module} for @{ $LIST->{entries} }' | cpanm -n
This module also helps lcpan produce a more meaningful result for "lcpan
related-mods" when it comes to finding related modules for the modules
listed in this Acme::CPANModules module.
HOMEPAGE
Please visit the project's homepage at
<https://metacpan.org/release/Acme-CPANModules-DumpingDataForDebugging>.
SOURCE
Source repository is at
<https://github.com/perlancar/perl-Acme-CPANModules-DumpingDataForDebugg
ing>.
BUGS
Please report any bugs or feature requests on the bugtracker website
<https://rt.cpan.org/Public/Dist/Display.html?Name=Acme-CPANModules-Dump
ingDataForDebugging>
When submitting a bug or request, please include a test-file or a patch
to an existing test-file that illustrates the bug or desired feature.
SEE ALSO
Acme::CPANModules - about the Acme::CPANModules namespace
cpanmodules - CLI tool to let you browse/view the lists
AUTHOR
perlancar <perlancar@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2020 by perlancar@cpan.org.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.