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author | matz <matz@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 1998-01-16 12:19:09 +0000 |
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committer | matz <matz@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 1998-01-16 12:19:09 +0000 |
commit | 62e41d3f2e48422bbdf1bb2db83ae60b255b1a1a (patch) | |
tree | 4d0edb1c1986e1578b181ebe2441acfee27f1fab /lib/delegate.rb | |
parent | 3db12e8b236ac8f88db8eb4690d10e4a3b8dbcd4 (diff) |
Initial revision
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@8 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'lib/delegate.rb')
-rw-r--r-- | lib/delegate.rb | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/lib/delegate.rb b/lib/delegate.rb new file mode 100644 index 0000000000..e5943cead8 --- /dev/null +++ b/lib/delegate.rb @@ -0,0 +1,44 @@ +# Delegation class that delegates even methods defined in super class, +# which can not be covered with normal method_missing hack. +# +# Delegater is the abstract delegation class. Need to redefine +# `__getobj__' method in the subclass. SimpleDelegater is the +# concrete subclass for simple delegation. +# +# Usage: +# foo = Object.new +# foo = SimpleDelegater.new(foo) +# foo.type # => Object + +class Delegater + + def initialize(obj) + preserved = ["id", "equal?", "__getobj__"] + for t in self.type.ancestors + preserved |= t.instance_methods + break if t == Delegater + end + for method in obj.methods + next if preserved.include? method + eval "def self.#{method}(*args); __getobj__.send :#{method}, *args; end" + end + end + + def __getobj__ + raise NotImplementError, "need to define `__getobj__'" + end + +end + +class SimpleDelegater<Delegater + + def initialize(obj) + super + @obj = obj + end + + def __getobj__ + @obj + end + +end |