golden hour

/usr/share/perl5

File/Folder	Size	Actions
AnyDBM_File.pm	2.56 KB
App	-
Archive	-
Attribute	-
AutoLoader.pm	14.66 KB
AutoSplit.pm	19.18 KB
B	-
Benchmark.pm	27.87 KB
CORE.pod	2.7 KB
CPAN	-
CPAN.pm	132.91 KB
Class	-
Compress	-
Config	-
DB.pm	18.43 KB
DBM_Filter	-
DBM_Filter.pm	14.06 KB
Devel	-
DirHandle.pm	1.52 KB
Dumpvalue.pm	16.5 KB
Encode	-
English.pm	4.34 KB
ExtUtils	-
File	-
FileCache.pm	5.44 KB
FileHandle.pm	6.62 KB
Filter	-
FindBin.pm	4.45 KB
Getopt	-
HTTP	-
I18N	-
IO	-
IPC	-
JSON	-
LWP	-
LWP.pm	21.15 KB
Locale	-
Log	-
Math	-
Memoize	-
Memoize.pm	34.4 KB
Module	-
NEXT.pm	18.05 KB
Net	-
Object	-
Package	-
Perl	-
PerlIO	-
PerlIO.pm	10.19 KB
Pod	-
Safe.pm	24.03 KB
Search	-
SelectSaver.pm	1.05 KB
SelfLoader.pm	16.97 KB
Symbol.pm	4.68 KB
Term	-
Test	-
Test.pm	28.13 KB
Text	-
Thread	-
Thread.pm	8.09 KB
Tie	-
Time	-
UNIVERSAL.pm	6.97 KB
URI	-
URI.pm	33.01 KB
Unicode	-
User	-
Version	-
XSLoader.pm	9.99 KB
_charnames.pm	29.8 KB
autouse.pm	4.14 KB
base.pm	6.37 KB
bigint.pm	17.44 KB
bignum.pm	18.23 KB
bigrat.pm	14.11 KB
blib.pm	2.04 KB
bytes.pm	2.96 KB
bytes_heavy.pl	758 B
charnames.pm	19.22 KB
deprecate.pm	3.01 KB
diagnostics.pm	17.96 KB
dumpvar.pl	14.96 KB
encoding	-
feature.pm	11.06 KB
fields.pm	9.28 KB
filetest.pm	3.91 KB
if.pm	1.13 KB
integer.pm	3.19 KB
less.pm	3.13 KB
locale.pm	2.72 KB
lwpcook.pod	9.05 KB
lwptut.pod	24.89 KB
open.pm	7.83 KB
overload	-
overload.pm	52.66 KB
overloading.pm	1.77 KB
perl5db.pl	302.79 KB
perlfaq.pm	94 B
pod	-
sigtrap.pm	7.46 KB
sort.pm	5.95 KB
strict.pm	3.84 KB
subs.pm	845 B
unicore	-
utf8.pm	7.6 KB
utf8_heavy.pl	30.1 KB
vars.pm	2.3 KB
vendor_perl	-
vmsish.pm	4.22 KB
warnings	-
warnings.pm	18.34 KB

Edit: base.pm

package base;

use strict 'vars';
use vars qw($VERSION);
$VERSION = '2.18';
$VERSION = eval $VERSION;

# constant.pm is slow
sub SUCCESS () { 1 }

sub PUBLIC     () { 2**0  }
sub PRIVATE    () { 2**1  }
sub INHERITED  () { 2**2  }
sub PROTECTED  () { 2**3  }

my $Fattr = \%fields::attr;

sub has_fields {
    my($base) = shift;
    my $fglob = ${"$base\::"}{FIELDS};
    return( ($fglob && 'GLOB' eq ref($fglob) && *$fglob{HASH}) ? 1 : 0 );
}

sub has_attr {
    my($proto) = shift;
    my($class) = ref $proto || $proto;
    return exists $Fattr->{$class};
}

sub get_attr {
    $Fattr->{$_[0]} = [1] unless $Fattr->{$_[0]};
    return $Fattr->{$_[0]};
}

if ($] < 5.009) {
    *get_fields = sub {
        # Shut up a possible typo warning.
        () = \%{$_[0].'::FIELDS'};
        my $f = \%{$_[0].'::FIELDS'};

# should be centralized in fields? perhaps
        # fields::mk_FIELDS_be_OK. Peh. As long as %{ $package . '::FIELDS' }
        # is used here anyway, it doesn't matter.
        bless $f, 'pseudohash' if (ref($f) ne 'pseudohash');

return $f;
    }
}
else {
    *get_fields = sub {
        # Shut up a possible typo warning.
        () = \%{$_[0].'::FIELDS'};
        return \%{$_[0].'::FIELDS'};
    }
}

sub import {
    my $class = shift;

return SUCCESS unless @_;

# List of base classes from which we will inherit %FIELDS.
    my $fields_base;

my $inheritor = caller(0);

my @bases;
    foreach my $base (@_) {
        if ( $inheritor eq $base ) {
            warn "Class '$inheritor' tried to inherit from itself\n";
        }

next if grep $_->isa($base), ($inheritor, @bases);

# Following blocks help isolate $SIG{__DIE__} changes
        {
            my $sigdie;
            {
                local $SIG{__DIE__};
                eval "require $base";
                # Only ignore "Can't locate" errors from our eval require.
                # Other fatal errors (syntax etc) must be reported.
                die if $@ && $@ !~ /^Can't locate .*? at \(eval /;
                unless (%{"$base\::"}) {
                    require Carp;
                    local $" = " ";
                    Carp::croak(<<ERROR);
Base class package "$base" is empty.
    (Perhaps you need to 'use' the module which defines that package first,
    or make that module available in \@INC (\@INC contains: @INC).
ERROR
                }
                $sigdie = $SIG{__DIE__} || undef;
            }
            # Make sure a global $SIG{__DIE__} makes it out of the localization.
            $SIG{__DIE__} = $sigdie if defined $sigdie;
        }
        push @bases, $base;

if ( has_fields($base) || has_attr($base) ) {
            # No multiple fields inheritance *suck*
            if ($fields_base) {
                require Carp;
                Carp::croak("Can't multiply inherit fields");
            } else {
                $fields_base = $base;
            }
        }
    }
    # Save this until the end so it's all or nothing if the above loop croaks.
    push @{"$inheritor\::ISA"}, @bases;

if( defined $fields_base ) {
        inherit_fields($inheritor, $fields_base);
    }
}

sub inherit_fields {
    my($derived, $base) = @_;

return SUCCESS unless $base;

my $battr = get_attr($base);
    my $dattr = get_attr($derived);
    my $dfields = get_fields($derived);
    my $bfields = get_fields($base);

$dattr->[0] = @$battr;

if( keys %$dfields ) {
        warn <<"END";
$derived is inheriting from $base but already has its own fields!
This will cause problems.  Be sure you use base BEFORE declaring fields.
END

}

# Iterate through the base's fields adding all the non-private
    # ones to the derived class.  Hang on to the original attribute
    # (Public, Private, etc...) and add Inherited.
    # This is all too complicated to do efficiently with add_fields().
    while (my($k,$v) = each %$bfields) {
        my $fno;
        if ($fno = $dfields->{$k} and $fno != $v) {
            require Carp;
            Carp::croak ("Inherited fields can't override existing fields");
        }

if( $battr->[$v] & PRIVATE ) {
            $dattr->[$v] = PRIVATE | INHERITED;
        }
        else {
            $dattr->[$v] = INHERITED | $battr->[$v];
            $dfields->{$k} = $v;
        }
    }

foreach my $idx (1..$#{$battr}) {
        next if defined $dattr->[$idx];
        $dattr->[$idx] = $battr->[$idx] & INHERITED;
    }
}

__END__

=head1 NAME

base - Establish an ISA relationship with base classes at compile time

=head1 SYNOPSIS

package Baz;
    use base qw(Foo Bar);

=head1 DESCRIPTION

Unless you are using the C<fields> pragma, consider this module discouraged
in favor of the lighter-weight C<parent>.

Allows you to both load one or more modules, while setting up inheritance from
those modules at the same time.  Roughly similar in effect to

package Baz;
    BEGIN {
        require Foo;
        require Bar;
        push @ISA, qw(Foo Bar);
    }

When C<base> tries to C<require> a module, it will not die if it cannot find
the module's file, but will die on any other error.  After all this, should
your base class be empty, containing no symbols, C<base> will die. This is
useful for inheriting from classes in the same file as yourself but where
the filename does not match the base module name, like so:

# in Bar.pm
        package Foo;
        sub exclaim { "I can have such a thing?!" }

package Bar;
        use base "Foo";

There is no F<Foo.pm>, but because C<Foo> defines a symbol (the C<exclaim>
subroutine), C<base> will not die when the C<require> fails to load F<Foo.pm>.

C<base> will also initialize the fields if one of the base classes has it.
Multiple inheritance of fields is B<NOT> supported, if two or more base classes
each have inheritable fields the 'base' pragma will croak. See L<fields>
for a description of this feature.

The base class' C<import> method is B<not> called.

=head1 DIAGNOSTICS

=over 4

=item Base class package "%s" is empty.

base.pm was unable to require the base package, because it was not
found in your path.

=item Class 'Foo' tried to inherit from itself

Attempting to inherit from yourself generates a warning.

package Foo;
    use base 'Foo';

=back

=head1 HISTORY

This module was introduced with Perl 5.004_04.

=head1 CAVEATS

Due to the limitations of the implementation, you must use
base I<before> you declare any of your own fields.

=head1 SEE ALSO

L<fields>

=cut