比较数据结构的代码，deeply.pl，使用了Test::Differences模块，这样可以查看其中的差别。
#!/usr/bin/perl
use Test::More tests => 1;
use Test::Differences;
my $list1 =
[
[
[ 48, 12 ],
[ 32, 10 ],
],
[
[ 03, 28 ],
],
];
my $list2 =
[
[
[ 48, 12 ],
[ 32, 11 ],
],
[
[ 03, 28],
],
];
eq_or_diff( $list1, $list2, 'a tale of two references' );
运行结果如下：*号代表的是两个list中不同的地方
D:\loveperl>prove -v deeply.pl
deeply....1..1
not ok 1 - a tale of two references
# Failed test 'a tale of two references'
# at deeply.pl line 28.
# +----+-----------+-----------+
# | Elt|Got |Expected |
# +----+-----------+-----------+
# | 0|[ |[ |
# | 1| [ | [ |
# | 2| [ | [ |
# | 3| 48, | 48, |
# | 4| 12 | 12 |
# | 5| ], | ], |
# | 6| [ | [ |
# | 7| 32, | 32, |
# * 8| 10 | 11 *
# | 9| ] | ] |
# | 10| ], | ], |
# | 11| [ | [ |
# | 12| [ | [ |
# | 13| 3, | 3, |
# | 14| 28 | 28 |
# | 15| ] | ] |
# | 16| ] | ] |
# | 17|] |] |
# +----+-----------+-----------+
# Looks like you failed 1 test of 1.
dubious
Test returned status 1 (wstat 256, 0x100)
DIED. FAILED test 1
Failed 1/1 tests, 0.00% okay
Failed Test Stat Wstat Total Fail List of Failed
-------------------------------------------------------------------------------
deeply.pl 1 256 1 1 1
Failed 1/1 test scripts. 1/1 subtests failed.
Files=1, Tests=1, 0 wallclock secs ( 0.00 cusr + 0.00 csys = 0.00 CPU)
Failed 1/1 test programs. 1/1 subtests failed.
