Data-Dmp/lib/Data/Dmp.pm
## no critic: Modules::ProhibitAutomaticExportation
package Data::Dmp;
our $AUTHORITY = 'cpan:PERLANCAR'; # AUTHORITY
our $DATE = '2022-08-28'; # DATE
our $DIST = 'Data-Dmp'; # DIST
our $VERSION = '0.242'; # VERSION
use 5.010001;
use strict;
use warnings;
use Scalar::Util qw(looks_like_number blessed reftype refaddr);
require Exporter;
our @ISA = qw(Exporter);
our @EXPORT = qw(dd dmp);
our @EXPORT_OK = qw(dd_ellipsis dmp_ellipsis);
# for when dealing with circular refs
our %_seen_refaddrs;
our %_subscripts;
our @_fixups;
our $OPT_MAX_DUMP_LEN_BEFORE_ELLIPSIS = 70;
our $OPT_PERL_VERSION = "5.010";
our $OPT_REMOVE_PRAGMAS = 0;
our $OPT_DEPARSE = 1;
our $OPT_STRINGIFY_NUMBERS = 0;
# BEGIN COPY PASTE FROM Data::Dump
my %esc = (
"\a" => "\\a",
"\b" => "\\b",
"\t" => "\\t",
"\n" => "\\n",
"\f" => "\\f",
"\r" => "\\r",
"\e" => "\\e",
);
# put a string value in double quotes
sub _double_quote {
local($_) = $_[0];
# If there are many '"' we might want to use qq() instead
s/([\\\"\@\$])/\\$1/g;
return qq("$_") unless /[^\040-\176]/; # fast exit
s/([\a\b\t\n\f\r\e])/$esc{$1}/g;
# no need for 3 digits in escape for these
s/([\0-\037])(?!\d)/sprintf('\\%o',ord($1))/eg;
s/([\0-\037\177-\377])/sprintf('\\x%02X',ord($1))/eg;
s/([^\040-\176])/sprintf('\\x{%X}',ord($1))/eg;
return qq("$_");
}
# END COPY PASTE FROM Data::Dump
# BEGIN COPY PASTE FROM String::PerlQuote
sub _single_quote {
local($_) = $_[0];
s/([\\'])/\\$1/g;
return qq('$_');
}
# END COPY PASTE FROM String::PerlQuote
sub _dump_code {
my $code = shift;
state $deparse = do {
require B::Deparse;
B::Deparse->new("-l"); # -i option doesn't have any effect?
};
my $res = $deparse->coderef2text($code);
my ($res_before_first_line, $res_after_first_line) =
$res =~ /(.+?)^(#line .+)/ms;
if ($OPT_REMOVE_PRAGMAS) {
$res_before_first_line = "{";
} elsif ($OPT_PERL_VERSION < 5.016) {
# older perls' feature.pm doesn't yet support q{no feature ':all';}
# so we replace it with q{no feature}.
$res_before_first_line =~ s/no feature ':all';/no feature;/m;
}
$res_after_first_line =~ s/^#line .+//gm;
$res = "sub" . $res_before_first_line . $res_after_first_line;
$res =~ s/^\s+//gm;
$res =~ s/\n+//g;
$res =~ s/;\}\z/}/;
$res;
}
sub _quote_key {
$_[0] =~ /\A-?[A-Za-z_][A-Za-z0-9_]*\z/ ||
$_[0] =~ /\A-?[1-9][0-9]{0,8}\z/ ? $_[0] : _double_quote($_[0]);
}
sub _dump {
my ($val, $subscript) = @_;
my $ref = ref($val);
if ($ref eq '') {
if (!defined($val)) {
return "undef";
} elsif (looks_like_number($val) && !$OPT_STRINGIFY_NUMBERS &&
# perl does several normalizations to number literal, e.g.
# "+1" becomes 1, 0123 is octal literal, etc. make sure we
# only leave out quote when the number is not normalized
$val eq $val+0 &&
# perl also doesn't recognize Inf and NaN as numeric
# literals (ref: perldata) so these unquoted literals will
# choke under 'use strict "subs"
$val !~ /\A-?(?:inf(?:inity)?|nan)\z/i
) {
return $val;
} else {
return _double_quote($val);
}
}
my $refaddr = refaddr($val);
$_subscripts{$refaddr} //= $subscript;
if ($_seen_refaddrs{$refaddr}++) {
my $target = "\$var" .
($_subscripts{$refaddr} ? "->$_subscripts{$refaddr}" : "");
push @_fixups, "\$var->$subscript=$target;";
return _single_quote($target);
}
my $class;
if ($ref eq 'Regexp' || $ref eq 'REGEXP') {
require Regexp::Stringify;
return Regexp::Stringify::stringify_regexp(
regexp=>$val, with_qr=>1, plver=>$OPT_PERL_VERSION);
}
if (blessed $val) {
$class = $ref;
$ref = reftype($val);
}
my $res;
if ($ref eq 'ARRAY') {
$res = "[";
my $i = 0;
for (@$val) {
$res .= "," if $i;
$res .= _dump($_, "$subscript\[$i]");
$i++;
}
$res .= "]";
} elsif ($ref eq 'HASH') {
$res = "{";
my $i = 0;
for (sort keys %$val) {
$res .= "," if $i++;
my $k = _quote_key($_);
my $v = _dump($val->{$_}, "$subscript\{$k}");
$res .= "$k=>$v";
}
$res .= "}";
} elsif ($ref eq 'SCALAR') {
if (defined $class) {
$res = "do{my\$o="._dump($$val, $subscript).";\\\$o}";
} else {
$res = "\\"._dump($$val, $subscript);
}
} elsif ($ref eq 'REF') {
$res = "\\"._dump($$val, $subscript);
} elsif ($ref eq 'CODE') {
$res = $OPT_DEPARSE ? _dump_code($val) : 'sub{"DUMMY"}';
} else {
die "Sorry, I can't dump $val (ref=$ref) yet";
}
$res = "bless($res,"._double_quote($class).")" if defined($class);
$res;
}
our $_is_dd;
our $_is_ellipsis;
sub _dd_or_dmp {
local %_seen_refaddrs;
local %_subscripts;
local @_fixups;
my $res;
if (@_ > 1) {
$res = "(" . join(",", map {_dump($_, '')} @_) . ")";
} else {
$res = _dump($_[0], '');
}
if (@_fixups) {
$res = "do{my\$var=$res;" . join("", @_fixups) . "\$var}";
}
if ($_is_ellipsis) {
$res = substr($res, 0, $OPT_MAX_DUMP_LEN_BEFORE_ELLIPSIS) . '...'
if length($res) > $OPT_MAX_DUMP_LEN_BEFORE_ELLIPSIS;
}
if ($_is_dd) {
say $res;
return wantarray() || @_ > 1 ? @_ : $_[0];
} else {
return $res;
}
}
sub dd { local $_is_dd=1; _dd_or_dmp(@_) } # goto &sub doesn't work with local
sub dmp { goto &_dd_or_dmp }
sub dd_ellipsis { local $_is_dd=1; local $_is_ellipsis=1; _dd_or_dmp(@_) }
sub dmp_ellipsis { local $_is_ellipsis=1; _dd_or_dmp(@_) }
1;
# ABSTRACT: Dump Perl data structures as Perl code
__END__
=pod
=encoding UTF-8
=head1 NAME
Data::Dmp - Dump Perl data structures as Perl code
=head1 VERSION
This document describes version 0.242 of Data::Dmp (from Perl distribution Data-Dmp), released on 2022-08-28.
=head1 SYNOPSIS
use Data::Dmp; # exports dd() and dmp()
dd [1, 2, 3]; # prints "[1,2,3]"
$var = dmp({a => 1}); # -> "{a=>1}"
Print truncated dump (capped at L</$Data::Dmp::OPT_MAX_DUMP_LEN_BEFORE_ELLIPSIS>
characters):
use Data::Dmp qw(dd_ellipsis dmp_ellipsis);
dd_ellipsis [1..100];
=head1 DESCRIPTION
Data::Dmp is a Perl dumper like L<Data::Dumper>. It's compact (only about 200
lines of code long), starts fast and does not use any non-core modules except
L<Regexp::Stringify> when dumping regexes. It produces compact single-line
output (similar to L<Data::Dumper::Concise>). It roughly has the same speed as
Data::Dumper (usually a bit faster for smaller structures) and faster than
L<Data::Dump>, but does not offer the various formatting options. It supports
dumping objects, regexes, circular structures, coderefs. Its code is first based
on L<Data::Dump>: I removed all the parts that I don't need, particularly the
pretty formatting stuffs) and added some features that I need like proper regex
dumping and coderef deparsing.
=head1 VARIABLES
=head2 $Data::Dmp::OPT_PERL_VERSION
String, default: 5.010.
Set target Perl version. If you set this to, say C<5.010>, then the dumped code
will keep compatibility with Perl 5.10.0. This is used in the following ways:
=over
=item * passed to L<Regexp::Stringify>
=item * when dumping code references
For example, in perls earlier than 5.016, feature.pm does not understand:
no feature ':all';
so we replace it with:
no feature;
=back
=head2 $Data::Dmp::OPT_REMOVE_PRAGMAS
Bool, default: 0.
If set to 1, then pragmas at the start of coderef dump will be removed. Coderef
dump is produced by L<B::Deparse> and is of the form like:
sub { use feature 'current_sub', 'evalbytes', 'fc', 'say', 'state', 'switch', 'unicode_strings', 'unicode_eval'; $a <=> $b }
If you want to dump short coderefs, the pragmas might be distracting. You can
turn turn on this option which will make the above dump become:
sub { $a <=> $b }
Note that without the pragmas, the dump might be incorrect.
=head2 $Data::Dmp::OPT_DEPARSE
Bool, default: 1.
Can be set to 0 to skip deparsing code. Coderefs will be dumped as
C<sub{"DUMMY"}> instead, like in Data::Dump.
=head2 $Data::Dmp::OPT_STRINGIFY_NUMBERS
Bool, default: 0.
If set to true, will dump numbers as quoted string, e.g. 123 as "123" instead of
123. This might be helpful if you want to compute the hash of or get a canonical
representation of data structure.
=head2 $Data::Dmp::OPT_MAX_DUMP_LEN_BEFORE_ELLIPSIS
Int, default: 70.
Used by L</dd_ellipsis> and L</dmp_ellipsis>.
=head1 BENCHMARKS
[1..10]:
Rate/s Precision/s Data::Dump Data::Dumper Data::Dmp
Data::Dump 24404 95 -- -61.6% -75.6%
Data::Dumper 63580 210 160.5+-1.3% -- -36.4%
Data::Dmp 99940 130 309.5+-1.7% 57.18+-0.55% --
[1..100]:
Rate/s Precision/s Data::Dump Data::Dumper Data::Dmp
Data::Dump 2934.3 7.8 -- -75.3% -76.2%
Data::Dumper 11873 32 304.6+-1.5% -- -3.7%
Data::Dmp 12323.4 4 320+-1.1% 3.8+-0.28% --
Some mixed structure:
Rate/s Precision/s Data::Dump Data::Dmp Data::Dumper
Data::Dump 7161 12 -- -69.3% -78.7%
Data::Dmp 23303 29 225.43+-0.7% -- -30.6%
Data::Dumper 33573 56 368.8+-1.1% 44.07+-0.3% --
=head1 FUNCTIONS
=head2 dd
Usage:
dd($data, ...); # returns $data
Exported by default. Like C<Data::Dump>'s C<dd> (a.k.a. C<dump>), print one or
more data to STDOUT. Unlike C<Data::Dump>'s C<dd>, it I<always> prints and
return I<the original data> (like L<XXX>), making it convenient to insert into
expressions. This also removes ambiguity and saves one C<wantarray()> call.
=head2 dmp
Usage:
my $dump = dmp($data, ...);
Exported by default. Return dump result as string. Unlike C<Data::Dump>'s C<dd>
(a.k.a. C<dump>), it I<never> prints and only return the dump result.
=head2 dd_ellipsis
Usage:
dd_ellipsis($data, ...); # returns data
Just like L</dd>, except will truncate its output to
L</$Data::Dmp::OPT_MAX_DUMP_LEN_BEFORE_ELLIPSIS> characters if dump is too long.
Note that truncated dump will probably not be valid Perl code.
=head2 dmp_ellipsis
Usage:
my $dump = dd_ellipsis($data, ...); # returns data
Just like L</dmp>, except will truncate dump result to
L</$Data::Dmp::OPT_MAX_DUMP_LEN_BEFORE_ELLIPSIS> characters if dump is too long.
Note that truncated dump will probably not be valid Perl code.
=head1 FAQ
=head2 When to use Data::Dmp? How does it compare to other dumper modules?
Data::Dmp might be suitable for you if you want a relatively fast pure-Perl data
structure dumper to eval-able Perl code. It produces compact, single-line Perl
code but offers little/no formatting options. Data::Dmp and Data::Dump module
family usually produce Perl code that is "more eval-able", e.g. it can recreate
circular structure.
L<Data::Dump> produces visually nicer output (some alignment, use of range
operator to shorten lists, use of base64 for binary data, etc) but no built-in
option to produce compact/single-line output. It's more suitable for debugging.
It's also relatively slow. I usually use its variant, L<Data::Dump::Color>, for
console debugging.
L<Data::Dumper> is a core module, offers a lot of formatting options (like
disabling hash key sorting, setting verboseness/indent level, and so on) but you
usually have to configure it quite a bit before it does exactly like you want
(that's why there are modules on CPAN that are just wrapping Data::Dumper with
some configuration, like L<Data::Dumper::Concise> et al). It does not support
dumping Perl code that can recreate circular structures.
Of course, dumping to eval-able Perl code is slow (not to mention the cost of
re-loading the code back to in-memory data, via eval-ing) compared to dumping to
JSON, YAML, Sereal, or other format. So you need to decide first whether this is
the appropriate route you want to take. (But note that there is also
L<Data::Dumper::Limited> and L<Data::Undump> which uses a format similar to
Data::Dumper but lets you load the serialized data without eval-ing them, thus
achieving the speed comparable to JSON::XS).
=head2 Is the output guaranteed to be single line dump?
No. Some things can still produce multiline dump, e.g. newline in regular
expression.
=head1 HOMEPAGE
Please visit the project's homepage at L<https://metacpan.org/release/Data-Dmp>.
=head1 SOURCE
Source repository is at L<https://github.com/perlancar/perl-Data-Dmp>.
=head1 SEE ALSO
L<Data::Dump> and other variations/derivate works in Data::Dump::*.
L<Data::Dumper> and its variants.
L<Data::Printer>.
L<YAML>, L<JSON>, L<Storable>, L<Sereal>, and other serialization formats.
=head1 AUTHOR
perlancar <perlancar@cpan.org>
=head1 CONTRIBUTING
To contribute, you can send patches by email/via RT, or send pull requests on
GitHub.
Most of the time, you don't need to build the distribution yourself. You can
simply modify the code, then test via:
% prove -l
If you want to build the distribution (e.g. to try to install it locally on your
system), you can install L<Dist::Zilla>,
L<Dist::Zilla::PluginBundle::Author::PERLANCAR>,
L<Pod::Weaver::PluginBundle::Author::PERLANCAR>, and sometimes one or two other
Dist::Zilla- and/or Pod::Weaver plugins. Any additional steps required beyond
that are considered a bug and can be reported to me.
=head1 COPYRIGHT AND LICENSE
This software is copyright (c) 2022, 2021, 2020, 2017, 2016, 2015, 2014 by perlancar <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.
=head1 BUGS
Please report any bugs or feature requests on the bugtracker website L<https://rt.cpan.org/Public/Dist/Display.html?Name=Data-Dmp>
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.
=cut