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authorPerl 5 Porters <perl5-porters@africa.nicoh.com>1996-10-03 02:44:32 +0000
committerAndy Dougherty <doughera@lafcol.lafayette.edu>1996-10-03 02:44:32 +0000
commitdef3c1025d0dad82e1d840f9be58127695f1bd62 (patch)
tree39a56cd3f55e017083c96b3fbaaa2338bb8d5dfd /lib/UNIVERSAL.pm
parentac323e15ded2bfe9f2b682e2c761a4505058fedc (diff)
downloadperl-def3c1025d0dad82e1d840f9be58127695f1bd62.tar.gz
Add in stub file.
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+package UNIVERSAL;
+
+require Exporter;
+@ISA = qw(Exporter);
+@EXPORT_OK = qw(isa);
+
+1;
+__END__
+
+=head1 NAME
+
+UNIVERSAL - base class for ALL classes (blessed references)
+
+=head1 SYNOPSIS
+
+ use UNIVERSAL qw(isa);
+
+ $yes = isa($ref, "HASH");
+ $io = $fd->isa("IO::Handle");
+ $sub = $obj->can('print');
+
+=head1 DESCRIPTION
+
+C<UNIVERSAL> is the base class which all bless references will inherit from,
+see L<perlobj>
+
+C<UNIVERSAL> provides the following methods
+
+=over 4
+
+=item isa ( TYPE )
+
+C<isa> returns I<true> if C<REF> is blessed into package C<TYPE>
+or inherits from package C<TYPE>.
+
+C<isa> can be called as either a static or object method call.
+
+=item can ( METHOD )
+
+C<can> checks if the object has a method called C<METHOD>. If it does
+then a reference to the sub is returned. If it does not the I<undef>
+is returned.
+
+C<can> can be called as either a static or object method call.
+
+=item VERSION ( [ REQUIRE ] )
+
+C<VERSION> will return the value of the variable C<$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>.
+
+C<VERSION> can be called as either a static or object method call.
+
+=back
+
+C<UNIVERSAL> also optionally exports the following subroutines
+
+=over 4
+
+=item isa ( REF, TYPE )
+
+C<isa> returns I<true> if the first argument is a reference and either
+of the following statements is true.
+
+=over 8
+
+=item
+
+C<REF> is a blessed reference and is blessed into package C<TYPE>
+or inherits from package C<TYPE>
+
+=item
+
+C<REF> is a reference to a C<TYPE> of perl variable (er 'HASH')
+
+=back
+
+=back
+
+=cut