Initial import of Perl5. The king is dead; long live the king!

1 files changed, 97 insertions, 0 deletions

diff --git a/contrib/perl5/lib/UNIVERSAL.pm b/contrib/perl5/lib/UNIVERSAL.pm
new file mode 100644
index 0000000..dc02423
--- /dev/null
+++ b/contrib/perl5/lib/UNIVERSAL.pm
@@ -0,0 +1,97 @@
+package UNIVERSAL;
+
+# UNIVERSAL should not contain any extra subs/methods beyond those
+# that it exists to define. The use of Exporter below is a historical
+# accident that should be fixed sometime.
+require Exporter;
+*import = \&Exporter::import;
+@EXPORT_OK = qw(isa can);
+
+1;
+__END__
+
+=head1 NAME
+
+UNIVERSAL - base class for ALL classes (blessed references)
+
+=head1 SYNOPSIS
+
+    $io = $fd->isa("IO::Handle");
+    $sub = $obj->can('print');
+
+    $yes = UNIVERSAL::isa($ref, "HASH");
+
+=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 then 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
+
+The C<isa> and C<can> methods can also be called as subroutines
+
+=over 4
+
+=item UNIVERSAL::isa ( VAL, 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<VAL> is a blessed reference and is blessed into package C<TYPE>
+or inherits from package C<TYPE>
+
+=item
+
+C<VAL> is a reference to a C<TYPE> of perl variable (er 'HASH')
+
+=back
+
+=item UNIVERSAL::can ( VAL, METHOD )
+
+If C<VAL> is a blessed reference which has a method called C<METHOD>,
+C<can> returns a reference to the subroutine.   If C<VAL> is not
+a blessed reference, or if it does not have a method C<METHOD>,
+I<undef> is returned.
+
+=back
+
+These subroutines should I<not> be imported via S<C<use UNIVERSAL qw(...)>>.
+If you want simple local access to them you can do
+
+  *isa = \&UNIVERSAL::isa;
+
+to import isa into your package.
+
+=cut