patch@32181 File::Copy.pm patches for VMS

[p5sagit/p5-mst-13.2.git] / lib / mro.pm

diff --git a/lib/mro.pm b/lib/mro.pm
index 31da81b..858b8e5 100644 (file)
--- a/lib/mro.pm
+++ b/lib/mro.pm
@@ -9,14 +9,33 @@ package mro;
 use strict;
 use warnings;
 
-# mro.pm versions < 1.00 reserved for possible CPAN mro dist
-#  (for partial back-compat to 5.[68].x)
+# mro.pm versions < 1.00 reserved for MRO::Compat
+#  for partial back-compat to 5.[68].x
 our $VERSION = '1.00';
 
 sub import {
     mro::set_mro(scalar(caller), $_[1]) if $_[1];
 }
 
+package # hide me from PAUSE
+    next;
+
+sub can { mro::_nextcan($_[0], 0) }
+
+sub method {
+    my $method = mro::_nextcan($_[0], 1);
+    goto &$method;
+}
+
+package # hide me from PAUSE
+    maybe::next;
+
+sub method {
+    my $method = mro::_nextcan($_[0], 0);
+    goto &$method if defined $method;
+    return;
+}
+
 1;
 
 __END__
@@ -27,6 +46,8 @@ mro - Method Resolution Order
 
 =head1 SYNOPSIS
 
+  use mro; # enables next::method and friends globally
+
   use mro 'dfs'; # enable DFS MRO for this class (Perl default)
   use mro 'c3'; # enable C3 MRO for this class
 
@@ -43,9 +64,12 @@ implementation for older Perls.
 
 It's possible to change the MRO of a given class either by using C<use
 mro> as shown in the synopsis, or by using the L</mro::set_mro> function
-below.  The functions do not require loading the C<mro> module, as they
-are actually provided by the core perl interpreter.  The C<use mro> syntax
-is just syntactic sugar for setting the current package's MRO.
+below.  The functions in the mro namespace do not require loading the
+C<mro> module, as they are actually provided by the core perl interpreter.
+
+The special methods C<next::method>, C<next::can>, and
+C<maybe::next::method> are not available until this C<mro> module
+has been loaded via C<use> or C<require>.
 
 =head1 The C3 MRO
 
@@ -291,39 +315,6 @@ In simple cases, it is equivalent to:
 But there are some cases where only this solution
 works (like C<goto &maybe::next::method>);
 
-=head1 PERFORMANCE CONSIDERATIONS
-
-Specifying the mro type of a class before setting C<@ISA> will
-be faster than the other way around.  Also, making all of your
-C<@ISA> manipulations in a single assignment statement will be
-faster that doing them one by one via C<push> (which is what
-C<use base> does currently).
-
-Examples:
-
-  # The slowest way
-  package Foo;
-  use base qw/A B C/;
-  use mro 'c3';
-
-  # The fastest way
-  # (not exactly equivalent to above,
-  #   as base.pm can do other magic)
-  use mro 'c3';
-  use A ();
-  use B ();
-  use C ();
-  our @ISA = qw/A B C/;
-
-Generally speaking, every time C<@ISA> is modified, the MRO
-of that class will be recalculated, because of the way array
-magic works.  Pushing multiple items onto C<@ISA> in one push
-statement still counts as multiple modifications.  However,
-assigning a list to C<@ISA> only counts as a single
-modification.  Thus if you really need to do C<push> as
-opposed to assignment, C<@ISA = (@ISA, qw/A B C/);>
-will still be faster than C<push(@ISA, qw/A B C/);>
-
 =head1 SEE ALSO
 
 =head2 The original Dylan paper