golden hour

/usr/share/perl/5.30.0

File/Folder	Size	Actions
AnyDBM_File.pm	2.56 KB
App	-
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AutoLoader.pm	15.43 KB
AutoSplit.pm	19.18 KB
B	-
Benchmark.pm	30.3 KB
CORE.pod	3.11 KB
CPAN	-
CPAN.pm	138.75 KB
Carp	-
Carp.pm	35.12 KB
Class	-
Compress	-
Config	-
DB.pm	18.48 KB
DBM_Filter	-
DBM_Filter.pm	14.05 KB
Devel	-
Digest	-
Digest.pm	10.45 KB
DirHandle.pm	2.04 KB
Dumpvalue.pm	17.14 KB
Encode	-
English.pm	4.65 KB
Env.pm	5.39 KB
Exporter	-
Exporter.pm	18.36 KB
ExtUtils	-
Fatal.pm	56.91 KB
File	-
FileCache.pm	5.42 KB
FileHandle.pm	6.63 KB
Filter	-
FindBin.pm	4.45 KB
Getopt	-
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I18N	-
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Internals.pod	2.51 KB
JSON	-
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Memoize.pm	35.34 KB
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NEXT.pm	18.54 KB
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PerlIO.pm	10.21 KB
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SelfLoader.pm	17.27 KB
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Test.pm	29.34 KB
Test2	-
Test2.pm	6.24 KB
Text	-
Thread	-
Thread.pm	8.09 KB
Tie	-
Time	-
UNIVERSAL.pm	6.44 KB
Unicode	-
User	-
XSLoader.pm	10.99 KB
_charnames.pm	32.39 KB
autodie	-
autodie.pm	12.58 KB
autouse.pm	4.14 KB
base.pm	10.7 KB
bigint.pm	22.85 KB
bignum.pm	20.64 KB
bigrat.pm	15.78 KB
blib.pm	2.01 KB
bytes.pm	3.65 KB
bytes_heavy.pl	758 B
charnames.pm	20.38 KB
constant.pm	14.38 KB
deprecate.pm	5.07 KB
diagnostics.pm	18.59 KB
dumpvar.pl	15.19 KB
encoding	-
experimental.pm	6.9 KB
feature.pm	17.28 KB
fields.pm	9.25 KB
filetest.pm	3.91 KB
if.pm	3.53 KB
integer.pm	3.18 KB
less.pm	3.13 KB
locale.pm	4.74 KB
meta_notation.pm	2.07 KB
ok.pm	967 B
open.pm	7.83 KB
overload	-
overload.pm	52.04 KB
overloading.pm	1.77 KB
parent.pm	2.51 KB
perl5db.pl	309.69 KB
perlfaq.pm	77 B
pod	-
sigtrap.pm	8.53 KB
sort.pm	3.82 KB
strict.pm	4.63 KB
subs.pm	901 B
unicore	-
utf8.pm	10.18 KB
utf8_heavy.pl	26.66 KB
vars.pm	2.4 KB
version	-
version.pm	1.93 KB
version.pod	9.6 KB
vmsish.pm	4.21 KB
warnings	-
warnings.pm	48.82 KB

Edit: UNIVERSAL.pm

package UNIVERSAL;

our $VERSION = '1.13';

# UNIVERSAL should not contain any extra subs/methods beyond those
# that it exists to define. The existence of import() below is a historical
# accident that can't be fixed without breaking code.

# Make sure that even though the import method is called, it doesn't do
# anything unless called on UNIVERSAL.
sub import {
    return unless $_[0] eq __PACKAGE__;
    return unless @_ > 1;
    require Carp;
    Carp::croak("UNIVERSAL does not export anything");
}

1;
__END__

=head1 NAME

UNIVERSAL - base class for ALL classes (blessed references)

=head1 SYNOPSIS

$is_io    = $fd->isa("IO::Handle");
    $is_io    = Class->isa("IO::Handle");

$does_log = $obj->DOES("Logger");
    $does_log = Class->DOES("Logger");

$sub      = $obj->can("print");
    $sub      = Class->can("print");

$sub      = eval { $ref->can("fandango") };
    $ver      = $obj->VERSION;

# but never do this!
    $is_io    = UNIVERSAL::isa($fd, "IO::Handle");
    $sub      = UNIVERSAL::can($obj, "print");

=head1 DESCRIPTION

C<UNIVERSAL> is the base class from which all blessed references inherit.
See L<perlobj>.

C<UNIVERSAL> provides the following methods:

=over 4

=item C<< $obj->isa( TYPE ) >>

=item C<< CLASS->isa( TYPE ) >>

=item C<< eval { VAL->isa( TYPE ) } >>

Where

=over 4

=item C<TYPE>

is a package name

=item C<$obj>

is a blessed reference or a package name

=item C<CLASS>

is a package name

=item C<VAL>

is any of the above or an unblessed reference

=back

When used as an instance or class method (C<< $obj->isa( TYPE ) >>),
C<isa> returns I<true> if $obj is blessed into package C<TYPE> or
inherits from package C<TYPE>.

When used as a class method (C<< CLASS->isa( TYPE ) >>, sometimes
referred to as a static method), C<isa> returns I<true> if C<CLASS>
inherits from (or is itself) the name of the package C<TYPE> or
inherits from package C<TYPE>.

If you're not sure what you have (the C<VAL> case), wrap the method call in an
C<eval> block to catch the exception if C<VAL> is undefined.

If you want to be sure that you're calling C<isa> as a method, not a class,
check the invocand with C<blessed> from L<Scalar::Util> first:

use Scalar::Util 'blessed';

if ( blessed( $obj ) && $obj->isa("Some::Class") ) {
      ...
  }

=item C<< $obj->DOES( ROLE ) >>

=item C<< CLASS->DOES( ROLE ) >>

C<DOES> checks if the object or class performs the role C<ROLE>.  A role is a
named group of specific behavior (often methods of particular names and
signatures), similar to a class, but not necessarily a complete class by
itself.  For example, logging or serialization may be roles.

C<DOES> and C<isa> are similar, in that if either is true, you know that the
object or class on which you call the method can perform specific behavior.
However, C<DOES> is different from C<isa> in that it does not care I<how> the
invocand performs the operations, merely that it does.  (C<isa> of course
mandates an inheritance relationship.  Other relationships include aggregation,
delegation, and mocking.)

By default, classes in Perl only perform the C<UNIVERSAL> role, as well as the
role of all classes in their inheritance.  In other words, by default C<DOES>
responds identically to C<isa>.

There is a relationship between roles and classes, as each class implies the
existence of a role of the same name.  There is also a relationship between
inheritance and roles, in that a subclass that inherits from an ancestor class
implicitly performs any roles its parent performs.  Thus you can use C<DOES> in
place of C<isa> safely, as it will return true in all places where C<isa> will
return true (provided that any overridden C<DOES> I<and> C<isa> methods behave
appropriately).

=item C<< $obj->can( METHOD ) >>

=item C<< CLASS->can( METHOD ) >>

=item C<< eval { VAL->can( METHOD ) } >>

C<can> checks if the object or class has a method called C<METHOD>. If it does,
then it returns a reference to the sub.  If it does not, then it returns
I<undef>.  This includes methods inherited or imported by C<$obj>, C<CLASS>, or
C<VAL>.

C<can> cannot know whether an object will be able to provide a method through
AUTOLOAD (unless the object's class has overridden C<can> appropriately), so a
return value of I<undef> does not necessarily mean the object will not be able
to handle the method call. To get around this some module authors use a forward
declaration (see L<perlsub>) for methods they will handle via AUTOLOAD. For
such 'dummy' subs, C<can> will still return a code reference, which, when
called, will fall through to the AUTOLOAD. If no suitable AUTOLOAD is provided,
calling the coderef will cause an error.

You may call C<can> as a class (static) method or an object method.

Again, the same rule about having a valid invocand applies -- use an C<eval>
block or C<blessed> if you need to be extra paranoid.

=item C<VERSION ( [ REQUIRE ] )>

C<VERSION> will return the value of the variable C<$VERSION> in the
package the object is blessed into. If C<REQUIRE> is given then
it will do a comparison and die if the package version is not
greater than or equal to C<REQUIRE>, or if either C<$VERSION> or C<REQUIRE>
is not a "lax" version number (as defined by the L<version> module).

The return from C<VERSION> will actually be the stringified version object
using the package C<$VERSION> scalar, which is guaranteed to be equivalent
but may not be precisely the contents of the C<$VERSION> scalar.  If you want
the actual contents of C<$VERSION>, use C<$CLASS::VERSION> instead.

C<VERSION> can be called as either a class (static) method or an object
method.

=back

=head1 WARNINGS

B<NOTE:> C<can> directly uses Perl's internal code for method lookup, and
C<isa> uses a very similar method and cache-ing strategy. This may cause
strange effects if the Perl code dynamically changes @ISA in any package.

You may add other methods to the UNIVERSAL class via Perl or XS code.
You do not need to C<use UNIVERSAL> to make these methods
available to your program (and you should not do so).

=head1 EXPORTS

None.

Previous versions of this documentation suggested using C<isa> as
a function to determine the type of a reference:

$yes = UNIVERSAL::isa($h, "HASH");
  $yes = UNIVERSAL::isa("Foo", "Bar");

The problem is that this code would I<never> call an overridden C<isa> method in
any class.  Instead, use C<reftype> from L<Scalar::Util> for the first case:

use Scalar::Util 'reftype';

$yes = reftype( $h ) eq "HASH";

and the method form of C<isa> for the second:

$yes = Foo->isa("Bar");

=cut