File Coverage

blib/lib/Data/Cmp.pm

Criterion	Covered	Total	%
statement	59	59	100.0
branch	31	32	96.8
condition	18	24	75.0
subroutine	6	6	100.0
pod	1	1	100.0
total	115	122	94.2

package Data::Cmp;

our $AUTHORITY = 'cpan:PERLANCAR'; # AUTHORITY
our $DATE = '2021-04-12'; # DATE
our $DIST = 'Data-Cmp'; # DIST
our $VERSION = '0.010'; # VERSION

use 5.010001;
use strict;
use warnings;

use Scalar::Util qw(blessed reftype refaddr);

require Exporter;
our @ISA = qw(Exporter);
our @EXPORT_OK = qw(cmp_data);

# for when dealing with circular refs
my %_seen_refaddrs;

sub _cmp_data {
    my $d1 = shift;
    my $d2 = shift;

    my $def1 = defined $d1;
    my $def2 = defined $d2;
    if ($def1) {
        return 1 if !$def2;
    } else {
        return $def2 ? -1 : 0;
    }

    # so both are defined ...

    my $reftype1 = reftype($d1);
    my $reftype2 = reftype($d2);
    if (!$reftype1 && !$reftype2) {
        return $d1 cmp $d2;
    } elsif ( $reftype1 xor $reftype2) { return 2 }

    # so both are refs ...

    return 2 if $reftype1 ne $reftype2;

    # so both are refs of the same type ...

    my $pkg1 = blessed($d1);
    my $pkg2 = blessed($d2);
    if (defined $pkg1) {
        return 2 unless defined $pkg2 && $pkg1 eq $pkg2;
    } else {
        return 2 if defined $pkg2;
    }

    # so both are non-objects or objects of the same class ...

    my $refaddr1 = refaddr($d1);
    my $refaddr2 = refaddr($d2);

    if ($reftype1 eq 'ARRAY' && !$_seen_refaddrs{$refaddr1} && !$_seen_refaddrs{$refaddr2}) {
        $_seen_refaddrs{$refaddr1}++;
        $_seen_refaddrs{$refaddr2}++;
      ELEM:
        for my $i (0..($#{$d1} < $#{$d2} ? $#{$d1} : $#{$d2})) {
            my $cmpres = _cmp_data($d1->[$i], $d2->[$i]);
            return $cmpres if $cmpres;
        }
        return $#{$d1} <=> $#{$d2};
    } elsif ($reftype1 eq 'HASH' && !$_seen_refaddrs{$refaddr1} && !$_seen_refaddrs{$refaddr2}) {
        $_seen_refaddrs{$refaddr1}++;
        $_seen_refaddrs{$refaddr2}++;
        my $nkeys1 = keys %$d1;
        my $nkeys2 = keys %$d2;
      KEY:
        for my $k (sort keys %$d1) {
            unless (exists $d2->{$k}) { return $nkeys1 <=> $nkeys2 || 2 }
            my $cmpres = _cmp_data($d1->{$k}, $d2->{$k});
            return $cmpres if $cmpres;
        }
        return $nkeys1 <=> $nkeys2;
    } else {
        return $refaddr1 == $refaddr2 ? 0 : 2;
    }
}

sub cmp_data {
    my $d1 = shift;
    my $d2 = shift;

    %_seen_refaddrs = ();
    _cmp_data($d1, $d2);
}

1;
# ABSTRACT: Compare two data structures, return -1/0/1 like cmp

__END__