summaryrefslogtreecommitdiff
path: root/trunk/lib/forwardable.rb
diff options
context:
space:
mode:
Diffstat (limited to 'trunk/lib/forwardable.rb')
-rw-r--r--trunk/lib/forwardable.rb177
1 files changed, 0 insertions, 177 deletions
diff --git a/trunk/lib/forwardable.rb b/trunk/lib/forwardable.rb
deleted file mode 100644
index a4af0217d0..0000000000
--- a/trunk/lib/forwardable.rb
+++ /dev/null
@@ -1,177 +0,0 @@
-#
-# forwardable.rb -
-# $Release Version: 1.1$
-# $Revision$
-# by Keiju ISHITSUKA(keiju@ishitsuka.com)
-# original definition by delegator.rb
-# Revised by Daniel J. Berger with suggestions from Florian Gross.
-#
-# Documentation by James Edward Gray II and Gavin Sinclair
-#
-# == Introduction
-#
-# This library allows you delegate method calls to an object, on a method by
-# method basis.
-#
-# == Notes
-#
-# Be advised, RDoc will not detect delegated methods.
-#
-# <b>forwardable.rb provides single-method delegation via the
-# def_delegator() and def_delegators() methods. For full-class
-# delegation via DelegateClass(), see delegate.rb.</b>
-#
-# == Examples
-#
-# === Forwardable
-#
-# Forwardable makes building a new class based on existing work, with a proper
-# interface, almost trivial. We want to rely on what has come before obviously,
-# but with delegation we can take just the methods we need and even rename them
-# as appropriate. In many cases this is preferable to inheritance, which gives
-# us the entire old interface, even if much of it isn't needed.
-#
-# class Queue
-# extend Forwardable
-#
-# def initialize
-# @q = [ ] # prepare delegate object
-# end
-#
-# # setup preferred interface, enq() and deq()...
-# def_delegator :@q, :push, :enq
-# def_delegator :@q, :shift, :deq
-#
-# # support some general Array methods that fit Queues well
-# def_delegators :@q, :clear, :first, :push, :shift, :size
-# end
-#
-# q = Queue.new
-# q.enq 1, 2, 3, 4, 5
-# q.push 6
-#
-# q.shift # => 1
-# while q.size > 0
-# puts q.deq
-# end
-#
-# q.enq "Ruby", "Perl", "Python"
-# puts q.first
-# q.clear
-# puts q.first
-#
-# <i>Prints:</i>
-#
-# 2
-# 3
-# 4
-# 5
-# 6
-# Ruby
-# nil
-#
-# Forwardable can be used to setup delegation at the object level as well.
-#
-# printer = String.new
-# printer.extend Forwardable # prepare object for delegation
-# printer.def_delegator "STDOUT", "puts" # add delegation for STDOUT.puts()
-# printer.puts "Howdy!"
-#
-# <i>Prints:</i>
-#
-# Howdy!
-
-#
-# The Forwardable module provides delegation of specified
-# methods to a designated object, using the methods #def_delegator
-# and #def_delegators.
-#
-# For example, say you have a class RecordCollection which
-# contains an array <tt>@records</tt>. You could provide the lookup method
-# #record_number(), which simply calls #[] on the <tt>@records</tt>
-# array, like this:
-#
-# class RecordCollection
-# extend Forwardable
-# def_delegator :@records, :[], :record_number
-# end
-#
-# Further, if you wish to provide the methods #size, #<<, and #map,
-# all of which delegate to @records, this is how you can do it:
-#
-# class RecordCollection
-# # extend Forwardable, but we did that above
-# def_delegators :@records, :size, :<<, :map
-# end
-# f = Foo.new
-# f.printf ...
-# f.gets
-# f.content_at(1)
-#
-# Also see the example at forwardable.rb.
-
-module Forwardable
- FORWARDABLE_VERSION = "1.0.0"
-
- # Takes a hash as its argument. The key is a symbol or an array of
- # symbols. These symbols correspond to method names. The value is
- # the accessor to which the methods will be delegated.
- #
- # :call-seq:
- # delegate method => accessor
- # delegate [method, method, ...] => accessor
- #
- def delegate(hash)
- hash.each{ |methods, accessor|
- methods = methods.to_s unless methods.respond_to?(:each)
- methods.each{ |method|
- def_instance_delegator(accessor, method)
- }
- }
- end
-
- #
- # Shortcut for defining multiple delegator methods, but with no
- # provision for using a different name. The following two code
- # samples have the same effect:
- #
- # def_delegators :@records, :size, :<<, :map
- #
- # def_delegator :@records, :size
- # def_delegator :@records, :<<
- # def_delegator :@records, :map
- #
- def def_instance_delegators(accessor, *methods)
- methods.delete("__send__")
- methods.delete("__id__")
- methods.each{ |method|
- def_instance_delegator(accessor, method)
- }
- end
-
- #
- # Defines a method _method_ which delegates to _obj_ (i.e. it calls
- # the method of the same name in _obj_). If _new_name_ is
- # provided, it is used as the name for the delegate method.
- #
- def def_instance_delegator(accessor, method, ali = method)
- str = %Q{
- def #{ali}(*args, &block)
- #{accessor}.send(:#{method}, *args, &block)
- end
- }
-
- # If it's not a class or module, it's an instance
- begin
- module_eval(str)
- rescue
- instance_eval(str)
- end
- end
-
- alias def_delegators def_instance_delegators
- alias def_delegator def_instance_delegator
-end
-
-# compatibility
-SingleForwardable = Forwardable