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authorKarl Berry <karl@freefriends.org>2012-05-21 00:15:27 +0000
committerKarl Berry <karl@freefriends.org>2012-05-21 00:15:27 +0000
commita4c42bfb2337d37da89d789cb8cc226367994e32 (patch)
treec3eabdef5d565a4e515d2be0d9d4d0540bde0250 /Master/tlpkg/tlperl/lib/Class/ISA.pm
parent8274475057f024d35332ac47c2e2f23ea156e6ed (diff)
perl 5.14.2 from siep
git-svn-id: svn://tug.org/texlive/trunk@26525 c570f23f-e606-0410-a88d-b1316a301751
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diff --git a/Master/tlpkg/tlperl/lib/Class/ISA.pm b/Master/tlpkg/tlperl/lib/Class/ISA.pm
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--- a/Master/tlpkg/tlperl/lib/Class/ISA.pm
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@@ -1,218 +0,0 @@
-package Class::ISA;
-require 5;
-use strict;
-use vars qw($Debug $VERSION);
-$VERSION = '0.36';
-$Debug = 0 unless defined $Debug;
-
-use if $] >= 5.011, 'deprecate';
-
-###########################################################################
-
-sub self_and_super_versions {
- no strict 'refs';
- map {
- $_ => (defined(${"$_\::VERSION"}) ? ${"$_\::VERSION"} : undef)
- } self_and_super_path($_[0])
-}
-
-# Also consider magic like:
-# no strict 'refs';
-# my %class2SomeHashr =
-# map { defined(%{"$_\::SomeHash"}) ? ($_ => \%{"$_\::SomeHash"}) : () }
-# Class::ISA::self_and_super_path($class);
-# to get a hash of refs to all the defined (and non-empty) hashes in
-# $class and its superclasses.
-#
-# Or even consider this incantation for doing something like hash-data
-# inheritance:
-# no strict 'refs';
-# %union_hash =
-# map { defined(%{"$_\::SomeHash"}) ? %{"$_\::SomeHash"}) : () }
-# reverse(Class::ISA::self_and_super_path($class));
-# Consider that reverse() is necessary because with
-# %foo = ('a', 'wun', 'b', 'tiw', 'a', 'foist');
-# $foo{'a'} is 'foist', not 'wun'.
-
-###########################################################################
-sub super_path {
- my @ret = &self_and_super_path(@_);
- shift @ret if @ret;
- return @ret;
-}
-
-#--------------------------------------------------------------------------
-sub self_and_super_path {
- # Assumption: searching is depth-first.
- # Assumption: '' (empty string) can't be a class package name.
- # Note: 'UNIVERSAL' is not given any special treatment.
- return () unless @_;
-
- my @out = ();
-
- my @in_stack = ($_[0]);
- my %seen = ($_[0] => 1);
-
- my $current;
- while(@in_stack) {
- next unless defined($current = shift @in_stack) && length($current);
- print "At $current\n" if $Debug;
- push @out, $current;
- no strict 'refs';
- unshift @in_stack,
- map
- { my $c = $_; # copy, to avoid being destructive
- substr($c,0,2) = "main::" if substr($c,0,2) eq '::';
- # Canonize the :: -> main::, ::foo -> main::foo thing.
- # Should I ever canonize the Foo'Bar = Foo::Bar thing?
- $seen{$c}++ ? () : $c;
- }
- @{"$current\::ISA"}
- ;
- # I.e., if this class has any parents (at least, ones I've never seen
- # before), push them, in order, onto the stack of classes I need to
- # explore.
- }
-
- return @out;
-}
-#--------------------------------------------------------------------------
-1;
-
-__END__
-
-=head1 NAME
-
-Class::ISA - report the search path for a class's ISA tree
-
-=head1 SYNOPSIS
-
- # Suppose you go: use Food::Fishstick, and that uses and
- # inherits from other things, which in turn use and inherit
- # from other things. And suppose, for sake of brevity of
- # example, that their ISA tree is the same as:
-
- @Food::Fishstick::ISA = qw(Food::Fish Life::Fungus Chemicals);
- @Food::Fish::ISA = qw(Food);
- @Food::ISA = qw(Matter);
- @Life::Fungus::ISA = qw(Life);
- @Chemicals::ISA = qw(Matter);
- @Life::ISA = qw(Matter);
- @Matter::ISA = qw();
-
- use Class::ISA;
- print "Food::Fishstick path is:\n ",
- join(", ", Class::ISA::super_path('Food::Fishstick')),
- "\n";
-
-That prints:
-
- Food::Fishstick path is:
- Food::Fish, Food, Matter, Life::Fungus, Life, Chemicals
-
-=head1 DESCRIPTION
-
-Suppose you have a class (like Food::Fish::Fishstick) that is derived,
-via its @ISA, from one or more superclasses (as Food::Fish::Fishstick
-is from Food::Fish, Life::Fungus, and Chemicals), and some of those
-superclasses may themselves each be derived, via its @ISA, from one or
-more superclasses (as above).
-
-When, then, you call a method in that class ($fishstick->calories),
-Perl first searches there for that method, but if it's not there, it
-goes searching in its superclasses, and so on, in a depth-first (or
-maybe "height-first" is the word) search. In the above example, it'd
-first look in Food::Fish, then Food, then Matter, then Life::Fungus,
-then Life, then Chemicals.
-
-This library, Class::ISA, provides functions that return that list --
-the list (in order) of names of classes Perl would search to find a
-method, with no duplicates.
-
-=head1 FUNCTIONS
-
-=over
-
-=item the function Class::ISA::super_path($CLASS)
-
-This returns the ordered list of names of classes that Perl would
-search thru in order to find a method, with no duplicates in the list.
-$CLASS is not included in the list. UNIVERSAL is not included -- if
-you need to consider it, add it to the end.
-
-
-=item the function Class::ISA::self_and_super_path($CLASS)
-
-Just like C<super_path>, except that $CLASS is included as the first
-element.
-
-=item the function Class::ISA::self_and_super_versions($CLASS)
-
-This returns a hash whose keys are $CLASS and its
-(super-)superclasses, and whose values are the contents of each
-class's $VERSION (or undef, for classes with no $VERSION).
-
-The code for self_and_super_versions is meant to serve as an example
-for precisely the kind of tasks I anticipate that self_and_super_path
-and super_path will be used for. You are strongly advised to read the
-source for self_and_super_versions, and the comments there.
-
-=back
-
-=head1 CAUTIONARY NOTES
-
-* Class::ISA doesn't export anything. You have to address the
-functions with a "Class::ISA::" on the front.
-
-* Contrary to its name, Class::ISA isn't a class; it's just a package.
-Strange, isn't it?
-
-* Say you have a loop in the ISA tree of the class you're calling one
-of the Class::ISA functions on: say that Food inherits from Matter,
-but Matter inherits from Food (for sake of argument). If Perl, while
-searching for a method, actually discovers this cyclicity, it will
-throw a fatal error. The functions in Class::ISA effectively ignore
-this cyclicity; the Class::ISA algorithm is "never go down the same
-path twice", and cyclicities are just a special case of that.
-
-* The Class::ISA functions just look at @ISAs. But theoretically, I
-suppose, AUTOLOADs could bypass Perl's ISA-based search mechanism and
-do whatever they please. That would be bad behavior, tho; and I try
-not to think about that.
-
-* If Perl can't find a method anywhere in the ISA tree, it then looks
-in the magical class UNIVERSAL. This is rarely relevant to the tasks
-that I expect Class::ISA functions to be put to, but if it matters to
-you, then instead of this:
-
- @supers = Class::Tree::super_path($class);
-
-do this:
-
- @supers = (Class::Tree::super_path($class), 'UNIVERSAL');
-
-And don't say no-one ever told ya!
-
-* When you call them, the Class::ISA functions look at @ISAs anew --
-that is, there is no memoization, and so if ISAs change during
-runtime, you get the current ISA tree's path, not anything memoized.
-However, changing ISAs at runtime is probably a sign that you're out
-of your mind!
-
-=head1 COPYRIGHT AND LICENSE
-
-Copyright (c) 1999-2009 Sean M. Burke. All rights reserved.
-
-This library is free software; you can redistribute it and/or modify
-it under the same terms as Perl itself.
-
-=head1 AUTHOR
-
-Sean M. Burke C<sburke@cpan.org>
-
-=head1 MAINTAINER
-
-Maintained by Steffen Mueller C<smueller@cpan.org>.
-
-=cut
-