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Diffstat (limited to 'ruby_1_9_3/lib/forwardable.rb')
| -rw-r--r-- | ruby_1_9_3/lib/forwardable.rb | 285 |
1 files changed, 0 insertions, 285 deletions
diff --git a/ruby_1_9_3/lib/forwardable.rb b/ruby_1_9_3/lib/forwardable.rb deleted file mode 100644 index 2b71b904d0..0000000000 --- a/ruby_1_9_3/lib/forwardable.rb +++ /dev/null @@ -1,285 +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 -# -# SingleForwardable can be used to setup delegation at the object level as well. -# -# printer = String.new -# printer.extend SingleForwardable # prepare object for delegation -# printer.def_delegator "STDOUT", "puts" # add delegation for STDOUT.puts() -# printer.puts "Howdy!" -# -# Also, SingleForwardable can be use to Class or Module. -# -# module Facade -# extend SingleForwardable -# def_delegator :Implementation, :service -# -# class Implementation -# def service... -# end -# end -# -# If you want to use both Forwardable and SingleForwardable, you can -# use methods def_instance_delegator and def_single_delegator, etc. -# -# If the object isn't a Module and Class, You can too extend -# Forwardable module. -# 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 = "1.1.0" - - @debug = nil - class << self - attr_accessor :debug - end - - # 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 instance_delegate(hash) - hash.each{ |methods, accessor| - methods = [methods] 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__") - for method in methods - def_instance_delegator(accessor, method) - end - end - - # Define +method+ as delegator instance method with an optional - # alias name +ali+. Method calls to +ali+ will be delegated to - # +accessor.method+. - # - # class MyQueue - # extend Forwardable - # attr_reader :queue - # def initialize - # @queue = [] - # end - # - # def_delegator :@queue, :push, :mypush - # end - # - # q = MyQueue.new - # q.mypush 42 - # q.queue #=> [42] - # q.push 23 #=> NoMethodError - # - def def_instance_delegator(accessor, method, ali = method) - line_no = __LINE__; str = %{ - def #{ali}(*args, &block) - begin - #{accessor}.__send__(:#{method}, *args, &block) - rescue Exception - $@.delete_if{|s| %r"#{Regexp.quote(__FILE__)}"o =~ s} unless Forwardable::debug - ::Kernel::raise - end - end - } - # If it's not a class or module, it's an instance - begin - module_eval(str, __FILE__, line_no) - rescue - instance_eval(str, __FILE__, line_no) - end - - end - - alias delegate instance_delegate - alias def_delegators def_instance_delegators - alias def_delegator def_instance_delegator -end - -# -# Usage of The SingleForwardable is like Fowadable module. -# -module SingleForwardable - # 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 single_delegate(hash) - hash.each{ |methods, accessor| - methods = [methods] unless methods.respond_to?(:each) - methods.each{ |method| - def_single_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_single_delegators(accessor, *methods) - methods.delete("__send__") - methods.delete("__id__") - for method in methods - def_single_delegator(accessor, method) - end - 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_single_delegator(accessor, method, ali = method) - str = %{ - def #{ali}(*args, &block) - begin - #{accessor}.__send__(:#{method}, *args, &block) - rescue Exception - $@.delete_if{|s| %r"#{Regexp.quote(__FILE__)}"o =~ s} unless Forwardable::debug - ::Kernel::raise - end - end - } - - instance_eval(str, __FILE__, __LINE__) - end - - alias delegate single_delegate - alias def_delegators def_single_delegators - alias def_delegator def_single_delegator -end |