Errata

For any recent version of Perl (higher than 5.005), the patch level contains three numbers, not two, so it is just like the minor version.

For instance, the correct way to obtain CPAN version for Perl 5.14.2 would be:

print $Module::CoreList::version{5.014002}{CPAN}; # 1.9600_01

The following would not yield correct result:

print $Module::CoreList::version{5.01402}{CPAN}; # not right

my $second_ref_to_skipper = $reference_to_skipper;

The correct reference is not being copied. It should be following:

my $second_ref_to_skipper = $ref_to_skipper;

The 4th paragraph states "The second element is a reference to the correct provisions array, which we use in the grep expression".

The previous expression is:
my %whos_items = map {$_, 1} @{$_[1]};

'grep' in the paragraph should be 'map'.

"We could drop the braces from @{$items} and @{$$items} though."

The second syntax in the above line should be ${$items}[1]

sub is_hash_ref in last code example on page has 'my $hash_ref', but then in the eval and croak uses $ref_type instead.

sub is_hash_ref {
my $hash_ref = shift;

return eval { keys %$ref_type; 1 };
}

croak "I expected a hash reference!"
unless is_hash_ref( $ref_type );

Exercise, downloadable code and answer (p 317) are out of sync: exercise asks report for 4 castaway, answer lists 3 and draft dowloadable code has only 2 (missing both Howells, who must be key figures, because you need locate on some other place). Also, downloadable code lists character's properties. It makes feel, that something is wrong there.

On page 106 the 4th code sample, has $countdown('main')--; as the last line of subroutine add_to_tab. Is this a typo or do I not understand the code example?

"# reads from $read_fh, prints to $log_gh and $scalar_fh"

It should be $log_fh

In the array of patterns, the last regex has to be qr/Mrs?\. Howell/ instead of qr/Mrs?. Howell/
Assuming, the pattern should match Mr. Howell or Mrs. Howell

"my $passenger = qr/(?:Mr. Howell|Mrs. Howell|Mary Ann)/;"

The regex here should again have \. instead of the unescaped dot.

The list is initialised with qw() but "Mary Ann" is considered a single item in the list, when it would be two items if initialised in this way. The mistake is consistent throughout the example.

second to last line has syntax error; change ] to }, so it reads:
map {ORIGINAL => $_, FOLDED => "\F$_"},

There is no $skipper_bin in the final version of $skipper_home at the bottom of page 149, with the text (see Figure 10-1)

Thus, all the elements related to $skipper_bin should be removed from the "Skipper home PeGS"

The names of the modules referenced in this section don't match those in the image shown for Figure 11-1 or the description below it. The text talks about Navigation.pm and DropAnchor.pm, but the image shows navigate.pl, navigate.pm, and drop_anchor.pl.

"The build dist output ..."

should be

"The Build dist output ..."

page 181, Module::Starter::AddModule(v1.003) failed in Windows(Win7 64-bit, Strawberry Perl 5.16.3.1 64-bit):

In the source code of AddModule.pm:
...
system( './Build', 'manifest' );
...

would output the following message in Windows:

'.' is not recognized as an internal or external command, operable program or batch file.

But if the code had been changed to:
...
system( '.\Build', 'manifest' );
...

it's would get the message just like on page 182.

There is no "Horse.pm" created in earlier calls to module-starter (or even h2xs), so there are three lines that should not be present:
Horse:
file: lib/Horse.pm
version 0.01

"--name" should be "--module"

on page 188:

%module-starter --mb --name="Animal"
should be ...
%module-starter --mb --module="Animal"

and the one on page 189 is the same:

%module-starter --builder="ExtUtils::Makemaker" --name="Animal"
should be ...
%module-starter --builder="ExtUtils::Makemaker" --module="Animal"

"use Parent qw(Animal);" is not required in the code since both the methods are defined in the module.

Also, it makes the statement "We didn’t even need to initialize @Mouse::ISA to say that a Mouse was an Animal" in the next page pointless.

In the revisited code for Mouse.pm

"use parent qw(Animal);" is not required.
"use Animal;" will suffice.

In the TAP output, you run three tests, 1..3. test 1 is ok, test 2 and three say "not ok", but the result is "failed 1 test of 3". That should probably have been "failed 2 tests of 3".

Carp provides Carp as a replacement for warn.
.......should be:
Carp provides carp as a replacement for warn.

The following line:

my @modules = sort keys $Module::CoreList::version{5.014002};

yields a warning, that "keys on reference is experimental". It would be cleaner to rewrite it as:

my @modules = sort keys %{ $Module::CoreList::version{5.014002} };

The outpute of the program contains version numbers instead of dates. The correct output should look like:

AnyDBM_File 1994-10-17
App::Cpan 2009-12-20
App::Prove 2009-08-22
App::Prove::State 2009-08-22
App::Prove::State::Result 2009-08-22
App::Prove::State::Result::Test 2009-08-22

my $coderef = $type eq 'depth' : \&add_to_front : \&add_to_front;

should be

my $coderef = $type eq 'depth' ? \&add_to_front : \&add_to_back;

is( My::List::Util::sum( 4, −9, 37, 6 ), 38,
'4−9+37+6 is six' );

should be

is( My::List::Util::sum( 4, −9, 37, 6 ), 38,
'4−9+37+6 is 38' );

the following code in "sub sum_ok{ ... }" :

$label //= "The sum is $expected";

should be ...

$label ||= "The sum is $expected";


"//=" ------> "||="