From: Brandon L Black <blblack@gmail.com>
Date: Fri, 5 Jan 2007 02:07:32 +0000 (+0000)
Subject: break out most of the code to ::PurePerl
X-Git-Tag: 0.16~1^2~17
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=gitmo%2FClass-C3.git;a=commitdiff_plain;h=ecb0388de108f3f6fe103a3ca4f6e28e26892a70

break out most of the code to ::PurePerl
---

diff --git a/lib/Class/C3.pm b/lib/Class/C3.pm
index a9158ed..5c62422 100644
--- a/lib/Class/C3.pm
+++ b/lib/Class/C3.pm
@@ -4,220 +4,18 @@ package Class::C3;
 use strict;
 use warnings;
 
-use Scalar::Util 'blessed';
-use Algorithm::C3;
-
-our $VERSION = '0.14';
-
-# this is our global stash of both 
-# MRO's and method dispatch tables
-# the structure basically looks like
-# this:
-#
-#   $MRO{$class} = {
-#      MRO => [ <class precendence list> ],
-#      methods => {
-#          orig => <original location of method>,
-#          code => \&<ref to original method>
-#      },
-#      has_overload_fallback => (1 | 0)
-#   }
-#
-our %MRO;
-
-# use these for debugging ...
-sub _dump_MRO_table { %MRO }
-our $TURN_OFF_C3 = 0;
-
-# state tracking for initialize()/uninitialize()
-our $_initialized = 0;
-
-sub import {
-    my $class = caller();
-    # skip if the caller is main::
-    # since that is clearly not relevant
-    return if $class eq 'main';
-    return if $TURN_OFF_C3;
-    # make a note to calculate $class 
-    # during INIT phase
-    $MRO{$class} = undef unless exists $MRO{$class};
-}
-
-## initializers
-
-sub initialize {
-    # why bother if we don't have anything ...
-    return unless keys %MRO;
-    if($_initialized) {
-        uninitialize();
-        $MRO{$_} = undef foreach keys %MRO;
-    }
-    _calculate_method_dispatch_tables();
-    _apply_method_dispatch_tables();
-    %next::METHOD_CACHE = ();
-    $_initialized = 1;
-}
-
-sub uninitialize {
-    # why bother if we don't have anything ...
-    return unless keys %MRO;    
-    _remove_method_dispatch_tables();    
-    %next::METHOD_CACHE = ();
-    $_initialized = 0;
-}
-
-sub reinitialize { goto &initialize }
-
-## functions for applying C3 to classes
-
-sub _calculate_method_dispatch_tables {
-    my %merge_cache;
-    foreach my $class (keys %MRO) {
-        _calculate_method_dispatch_table($class, \%merge_cache);
-    }
-}
-
-sub _calculate_method_dispatch_table {
-    my ($class, $merge_cache) = @_;
-    no strict 'refs';
-    my @MRO = calculateMRO($class, $merge_cache);
-    $MRO{$class} = { MRO => \@MRO };
-    my $has_overload_fallback = 0;
-    my %methods;
-    # NOTE: 
-    # we do @MRO[1 .. $#MRO] here because it
-    # makes no sense to interogate the class
-    # which you are calculating for. 
-    foreach my $local (@MRO[1 .. $#MRO]) {
-        # if overload has tagged this module to 
-        # have use "fallback", then we want to
-        # grab that value 
-        $has_overload_fallback = ${"${local}::()"} 
-            if defined ${"${local}::()"};
-        foreach my $method (grep { defined &{"${local}::$_"} } keys %{"${local}::"}) {
-            # skip if already overriden in local class
-            next unless !defined *{"${class}::$method"}{CODE};
-            $methods{$method} = {
-                orig => "${local}::$method",
-                code => \&{"${local}::$method"}
-            } unless exists $methods{$method};
+our $VERSION = '0.15';
+
+BEGIN {
+    eval { require Class::C3::XS };
+    if($@) {
+        eval { require Class::C3::PurePerl };
+        if($@) {
+            die 'Could not load Class::C3::XS or Class::C3::PurePerl!';
         }
-    }    
-    # now stash them in our %MRO table
-    $MRO{$class}->{methods} = \%methods; 
-    $MRO{$class}->{has_overload_fallback} = $has_overload_fallback;        
-}
-
-sub _apply_method_dispatch_tables {
-    foreach my $class (keys %MRO) {
-        _apply_method_dispatch_table($class);
-    }     
-}
-
-sub _apply_method_dispatch_table {
-    my $class = shift;
-    no strict 'refs';
-    ${"${class}::()"} = $MRO{$class}->{has_overload_fallback}
-        if $MRO{$class}->{has_overload_fallback};
-    foreach my $method (keys %{$MRO{$class}->{methods}}) {
-        *{"${class}::$method"} = $MRO{$class}->{methods}->{$method}->{code};
-    }    
-}
-
-sub _remove_method_dispatch_tables {
-    foreach my $class (keys %MRO) {
-        _remove_method_dispatch_table($class);
-    }       
-}
-
-sub _remove_method_dispatch_table {
-    my $class = shift;
-    no strict 'refs';
-    delete ${"${class}::"}{"()"} if $MRO{$class}->{has_overload_fallback};    
-    foreach my $method (keys %{$MRO{$class}->{methods}}) {
-        delete ${"${class}::"}{$method}
-            if defined *{"${class}::${method}"}{CODE} && 
-               (*{"${class}::${method}"}{CODE} eq $MRO{$class}->{methods}->{$method}->{code});       
-    }   
-}
-
-## functions for calculating C3 MRO
-
-sub calculateMRO {
-    my ($class, $merge_cache) = @_;
-    return Algorithm::C3::merge($class, sub { 
-        no strict 'refs'; 
-        @{$_[0] . '::ISA'};
-    }, $merge_cache);
-}
-
-package  # hide me from PAUSE
-    next; 
-
-use strict;
-use warnings;
-
-use Scalar::Util 'blessed';
-
-our $VERSION = '0.05';
-
-our %METHOD_CACHE;
-
-sub method {
-    my $indirect = caller() =~ /^(?:next|maybe::next)$/;
-    my $level = $indirect ? 2 : 1;
-     
-    my ($method_caller, $label, @label);
-    while ($method_caller = (caller($level++))[3]) {
-      @label = (split '::', $method_caller);
-      $label = pop @label;
-      last unless
-        $label eq '(eval)' ||
-        $label eq '__ANON__';
     }
-    my $caller   = join '::' => @label;    
-    my $self     = $_[0];
-    my $class    = blessed($self) || $self;
-    
-    my $method = $METHOD_CACHE{"$class|$caller|$label"} ||= do {
-        
-        my @MRO = Class::C3::calculateMRO($class);
-        
-        my $current;
-        while ($current = shift @MRO) {
-            last if $caller eq $current;
-        }
-        
-        no strict 'refs';
-        my $found;
-        foreach my $class (@MRO) {
-            next if (defined $Class::C3::MRO{$class} && 
-                     defined $Class::C3::MRO{$class}{methods}{$label});          
-            last if (defined ($found = *{$class . '::' . $label}{CODE}));
-        }
-        
-        $found;
-    };
-
-    return $method if $indirect;
-
-    die "No next::method '$label' found for $self" if !$method;
-
-    goto &{$method};
 }
 
-sub can { method($_[0]) }
-
-package  # hide me from PAUSE
-    maybe::next; 
-
-use strict;
-use warnings;
-
-our $VERSION = '0.01';
-
-sub method { (next::method($_[0]) || return)->(@_) }
-
 1;
 
 __END__
diff --git a/lib/Class/C3/PurePerl.pm b/lib/Class/C3/PurePerl.pm
new file mode 100644
index 0000000..c05f8f2
--- /dev/null
+++ b/lib/Class/C3/PurePerl.pm
@@ -0,0 +1,253 @@
+
+package Class::C3::PurePerl;
+
+our $VERSION = '0.15';
+
+=pod
+
+=head1 NAME
+
+Class::C3::PurePerl - The default pure-Perl implementation of Class::C3
+
+=head1 DESCRIPTION
+
+This is the plain pure-Perl implementation of Class::C3.  The main Class::C3 package will
+first attempt to load L<Class::C3::XS>, and then failing that, will fall back to this.  Do
+not use this package directly, use L<Class::C3> instead.
+
+=head1 AUTHOR
+
+Stevan Little, E<lt>stevan@iinteractive.comE<gt>
+
+Brandon L. Black, E<lt>blblack@gmail.comE<gt>
+
+=head1 COPYRIGHT AND LICENSE
+
+Copyright 2005, 2006 by Infinity Interactive, Inc.
+
+L<http://www.iinteractive.com>
+
+This library is free software; you can redistribute it and/or modify
+it under the same terms as Perl itself. 
+
+=cut
+
+package # hide me from PAUSE
+    Class::C3;
+
+use strict;
+use warnings;
+
+use Scalar::Util 'blessed';
+use Algorithm::C3;
+
+# this is our global stash of both 
+# MRO's and method dispatch tables
+# the structure basically looks like
+# this:
+#
+#   $MRO{$class} = {
+#      MRO => [ <class precendence list> ],
+#      methods => {
+#          orig => <original location of method>,
+#          code => \&<ref to original method>
+#      },
+#      has_overload_fallback => (1 | 0)
+#   }
+#
+our %MRO;
+
+# use these for debugging ...
+sub _dump_MRO_table { %MRO }
+our $TURN_OFF_C3 = 0;
+
+# state tracking for initialize()/uninitialize()
+our $_initialized = 0;
+
+sub import {
+    my $class = caller();
+    # skip if the caller is main::
+    # since that is clearly not relevant
+    return if $class eq 'main';
+    return if $TURN_OFF_C3;
+    # make a note to calculate $class 
+    # during INIT phase
+    $MRO{$class} = undef unless exists $MRO{$class};
+}
+
+## initializers
+
+sub initialize {
+    # why bother if we don't have anything ...
+    return unless keys %MRO;
+    if($_initialized) {
+        uninitialize();
+        $MRO{$_} = undef foreach keys %MRO;
+    }
+    _calculate_method_dispatch_tables();
+    _apply_method_dispatch_tables();
+    %next::METHOD_CACHE = ();
+    $_initialized = 1;
+}
+
+sub uninitialize {
+    # why bother if we don't have anything ...
+    return unless keys %MRO;    
+    _remove_method_dispatch_tables();    
+    %next::METHOD_CACHE = ();
+    $_initialized = 0;
+}
+
+sub reinitialize { goto &initialize }
+
+## functions for applying C3 to classes
+
+sub _calculate_method_dispatch_tables {
+    my %merge_cache;
+    foreach my $class (keys %MRO) {
+        _calculate_method_dispatch_table($class, \%merge_cache);
+    }
+}
+
+sub _calculate_method_dispatch_table {
+    my ($class, $merge_cache) = @_;
+    no strict 'refs';
+    my @MRO = calculateMRO($class, $merge_cache);
+    $MRO{$class} = { MRO => \@MRO };
+    my $has_overload_fallback = 0;
+    my %methods;
+    # NOTE: 
+    # we do @MRO[1 .. $#MRO] here because it
+    # makes no sense to interogate the class
+    # which you are calculating for. 
+    foreach my $local (@MRO[1 .. $#MRO]) {
+        # if overload has tagged this module to 
+        # have use "fallback", then we want to
+        # grab that value 
+        $has_overload_fallback = ${"${local}::()"} 
+            if defined ${"${local}::()"};
+        foreach my $method (grep { defined &{"${local}::$_"} } keys %{"${local}::"}) {
+            # skip if already overriden in local class
+            next unless !defined *{"${class}::$method"}{CODE};
+            $methods{$method} = {
+                orig => "${local}::$method",
+                code => \&{"${local}::$method"}
+            } unless exists $methods{$method};
+        }
+    }    
+    # now stash them in our %MRO table
+    $MRO{$class}->{methods} = \%methods; 
+    $MRO{$class}->{has_overload_fallback} = $has_overload_fallback;        
+}
+
+sub _apply_method_dispatch_tables {
+    foreach my $class (keys %MRO) {
+        _apply_method_dispatch_table($class);
+    }     
+}
+
+sub _apply_method_dispatch_table {
+    my $class = shift;
+    no strict 'refs';
+    ${"${class}::()"} = $MRO{$class}->{has_overload_fallback}
+        if $MRO{$class}->{has_overload_fallback};
+    foreach my $method (keys %{$MRO{$class}->{methods}}) {
+        *{"${class}::$method"} = $MRO{$class}->{methods}->{$method}->{code};
+    }    
+}
+
+sub _remove_method_dispatch_tables {
+    foreach my $class (keys %MRO) {
+        _remove_method_dispatch_table($class);
+    }       
+}
+
+sub _remove_method_dispatch_table {
+    my $class = shift;
+    no strict 'refs';
+    delete ${"${class}::"}{"()"} if $MRO{$class}->{has_overload_fallback};    
+    foreach my $method (keys %{$MRO{$class}->{methods}}) {
+        delete ${"${class}::"}{$method}
+            if defined *{"${class}::${method}"}{CODE} && 
+               (*{"${class}::${method}"}{CODE} eq $MRO{$class}->{methods}->{$method}->{code});       
+    }   
+}
+
+## functions for calculating C3 MRO
+
+sub calculateMRO {
+    my ($class, $merge_cache) = @_;
+    return Algorithm::C3::merge($class, sub { 
+        no strict 'refs'; 
+        @{$_[0] . '::ISA'};
+    }, $merge_cache);
+}
+
+package  # hide me from PAUSE
+    next; 
+
+use strict;
+use warnings;
+
+our $VERSION = 0.15;
+
+use Scalar::Util 'blessed';
+
+our %METHOD_CACHE;
+
+sub method {
+    my $indirect = caller() =~ /^(?:next|maybe::next)$/;
+    my $level = $indirect ? 2 : 1;
+     
+    my ($method_caller, $label, @label);
+    while ($method_caller = (caller($level++))[3]) {
+      @label = (split '::', $method_caller);
+      $label = pop @label;
+      last unless
+        $label eq '(eval)' ||
+        $label eq '__ANON__';
+    }
+    my $caller   = join '::' => @label;    
+    my $self     = $_[0];
+    my $class    = blessed($self) || $self;
+    
+    my $method = $METHOD_CACHE{"$class|$caller|$label"} ||= do {
+        
+        my @MRO = Class::C3::calculateMRO($class);
+        
+        my $current;
+        while ($current = shift @MRO) {
+            last if $caller eq $current;
+        }
+        
+        no strict 'refs';
+        my $found;
+        foreach my $class (@MRO) {
+            next if (defined $Class::C3::MRO{$class} && 
+                     defined $Class::C3::MRO{$class}{methods}{$label});          
+            last if (defined ($found = *{$class . '::' . $label}{CODE}));
+        }
+        
+        $found;
+    };
+
+    return $method if $indirect;
+
+    die "No next::method '$label' found for $self" if !$method;
+
+    goto &{$method};
+}
+
+sub can { method($_[0]) }
+
+package  # hide me from PAUSE
+    maybe::next; 
+
+use strict;
+use warnings;
+
+our $VERSION = 0.15;
+
+sub method { (next::method($_[0]) || return)->(@_) }
+
+1;