X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FUNIVERSAL.pm;h=dc02423029edddd61ef853b75833ec4eb27b5e7c;hb=1ba752a043289c0682ba096aba08751ac71b298a;hp=c0e7ebdee2b2a0f5b2d9e43cc5a64c34ac454774;hpb=3314ffc68a11690bd9977cbdd7ea0601ad6ced13;p=p5sagit%2Fp5-mst-13.2.git

diff --git a/lib/UNIVERSAL.pm b/lib/UNIVERSAL.pm
index c0e7ebd..dc02423 100644
--- a/lib/UNIVERSAL.pm
+++ b/lib/UNIVERSAL.pm
@@ -1,8 +1,11 @@
 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;
-@ISA = qw(Exporter);
-@EXPORT_OK = qw(isa);
+*import = \&Exporter::import;
+@EXPORT_OK = qw(isa can);
 
 1;
 __END__
@@ -13,12 +16,11 @@ 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');
 
+    $yes = UNIVERSAL::isa($ref, "HASH");
+
 =head1 DESCRIPTION
 
 C<UNIVERSAL> is the base class which all bless references will inherit from,
@@ -54,11 +56,11 @@ C<VERSION> can be called as either a static or object method call.
 
 =back
 
-C<UNIVERSAL> also optionally exports the following subroutines
+The C<isa> and C<can> methods can also be called as subroutines
 
 =over 4
 
-=item isa ( REF, TYPE )
+=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.
@@ -67,15 +69,29 @@ of the following statements is true.
 
 =item
 
-C<REF> is a blessed reference and is blessed into package C<TYPE>
+C<VAL> 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')
+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