This commit was manufactured by cvs2svn to create branch 'ruby_1_8'.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@9142 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 86 insertions, 0 deletions

diff --git a/lib/yaml/tag.rb b/lib/yaml/tag.rb
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+# -*- mode: ruby; ruby-indent-level: 4; tab-width: 4 -*- vim: sw=4 ts=4
+# $Id$
+#
+# = yaml/tag.rb: methods for associating a taguri to a class.
+#
+# Author:: why the lucky stiff
+# 
+module YAML
+    # A dictionary of taguris which map to
+    # Ruby classes.
+    @@tagged_classes = {}
+    
+    # 
+    # Associates a taguri _tag_ with a Ruby class _cls_.  The taguri is used to give types
+    # to classes when loading YAML.  Taguris are of the form:
+    #
+    #   tag:authorityName,date:specific
+    #
+    # The +authorityName+ is a domain name or email address.  The +date+ is the date the type
+    # was issued in YYYY or YYYY-MM or YYYY-MM-DD format.  The +specific+ is a name for
+    # the type being added.
+    # 
+    # For example, built-in YAML types have 'yaml.org' as the +authorityName+ and '2002' as the
+    # +date+.  The +specific+ is simply the name of the type:
+    #
+    #  tag:yaml.org,2002:int
+    #  tag:yaml.org,2002:float
+    #  tag:yaml.org,2002:timestamp
+    #
+    # The domain must be owned by you on the +date+ declared.  If you don't own any domains on the
+    # date you declare the type, you can simply use an e-mail address.
+    #
+    #  tag:why@ruby-lang.org,2004:notes/personal
+    #
+    def YAML.tag_class( tag, cls )
+        if @@tagged_classes.has_key? tag
+            warn "class #{ @@tagged_classes[tag] } held ownership of the #{ tag } tag"
+        end
+        @@tagged_classes[tag] = cls
+    end
+
+    # Returns the complete dictionary of taguris, paired with classes.  The key for
+    # the dictionary is the full taguri.  The value for each key is the class constant
+    # associated to that taguri.
+    #
+    #  YAML.tagged_classes["tag:yaml.org,2002:int"] => Integer
+    #
+    def YAML.tagged_classes
+        @@tagged_classes
+    end
+end
+
+class Module # :nodoc: all
+    # Adds a taguri _tag_ to a class, used when dumping or loading the class
+    # in YAML.  See YAML::tag_class for detailed information on typing and
+    # taguris.
+    def yaml_as( tag, sc = true )
+        class_eval <<-"end;"
+            attr_accessor :taguri
+            def taguri
+                if respond_to? :to_yaml_type
+                    YAML::tagurize( to_yaml_type[1..-1] )
+                else
+                    return @taguri if @taguri
+                    tag = #{ tag.dump }
+                    if self.class.yaml_tag_subclasses? and self.class != YAML::tagged_classes[tag]
+                        tag = "\#{ tag }:\#{ self.class.yaml_tag_class_name }"
+                    end
+                    tag
+                end
+            end
+            def self.yaml_tag_subclasses?; #{ sc ? 'true' : 'false' }; end
+        end;
+        YAML::tag_class tag, self
+    end
+    # Transforms the subclass name into a name suitable for display
+    # in a subclassed tag.
+    def yaml_tag_class_name
+        self.name
+    end
+    # Transforms the subclass name found in the tag into a Ruby
+    # constant name.
+    def yaml_tag_read_class( name )
+        name
+    end
+end