## no critic: Modules::ProhibitAutomaticExportation

package Data::Dmp;

our $DATE = '2020-04-07'; # DATE
our $DIST = 'Data-Dmp'; # DIST
our $VERSION = '0.240'; # 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_PERL_VERSION = "5.010";
our $OPT_DEPARSE = 1;

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
    return qq("$_") unless /[^\040-\176]/;  # fast exit


    # no need for 3 digits in escape for these


    return qq("$_");

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;

        $res_before_first_line = "{";
    } elsif ($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/}/;

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{$refaddr}++) {
        push @_fixups, "\$a->$subscript=\$a",
            ($_subscripts{$refaddr} ? "->$_subscripts{$refaddr}" : ""), ";";
        return "'fix'";

    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]");
        $res .= "]";
    } elsif ($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') {
        $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);

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) {
        $res = "do{my\$a=$res;" . join("", @_fixups) . "\$a}";

    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(@_) }

# ABSTRACT: Dump Perl data structures as Perl code



=encoding UTF-8

=head1 NAME

Data::Dmp - Dump Perl data structures as Perl code

=head1 VERSION

This document describes version 0.240 of Data::Dmp (from Perl distribution Data-Dmp), released on 2020-04-07.


 use Data::Dmp; # exports dd() and dmp()
 dd [1, 2, 3]; # prints "[1,2,3]"
 $a = dmp({a => 1}); # -> "{a=>1}"

Print truncated dump (capped at L</$Data::Dmp::OPT_MAX_DUMP_LEN_BEFORE_ELLIPSIS>

 use Data::Dmp qw(dd_ellipsis dmp_ellipsis);
 dd_ellipsis [1..100];


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.


=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:


=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;


=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.


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.


Int, default: 70.

Used by L</dd_ellipsis> and L</dmp_ellipsis>.


                      Rate    Data::Dump Data::Dumper Data::Dmp
 Data::Dump    32032+-55/s            --       -64.6%    -73.9%
 Data::Dumper 90580+-110/s 182.77+-0.59%           --    -26.1%
 Data::Dmp    122575+-43/s 282.66+-0.67% 35.32+-0.17%        --
                       Rate    Data::Dump   Data::Dmp Data::Dumper
 Data::Dump   3890.6+-5.9/s            --      -73.7%       -73.7%
 Data::Dmp     14768.3+-5/s 279.59+-0.59%          --        -0.1%
 Data::Dumper   14790+-87/s   280.2+-2.3% 0.15+-0.59%           --
 Some mixed structure:
                     Rate    Data::Dump   Data::Dmp Data::Dumper
 Data::Dump    9035+-17/s            --      -68.3%       -80.9%
 Data::Dmp    28504+-10/s 215.47+-0.59%          --       -39.6%
 Data::Dumper 47188+-55/s   422.3+-1.1% 65.55+-0.2%           --


=head2 dd


 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


 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


 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


 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


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 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

=head1 SEE ALSO

L<Data::Dump> and other variations/derivate works in Data::Dump::*.

L<Data::Dumper> and its variants.


L<YAML>, L<JSON>, L<Storable>, L<Sereal>, and other serialization formats.

=head1 AUTHOR

perlancar <perlancar@cpan.org>


This software is copyright (c) 2020, 2017, 2016, 2015, 2014 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.