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Diffstat (limited to 'ruby_2_2/lib/forwardable.rb')
-rw-r--r-- | ruby_2_2/lib/forwardable.rb | 297 |
1 files changed, 0 insertions, 297 deletions
diff --git a/ruby_2_2/lib/forwardable.rb b/ruby_2_2/lib/forwardable.rb deleted file mode 100644 index e78b9ed1e0..0000000000 --- a/ruby_2_2/lib/forwardable.rb +++ /dev/null @@ -1,297 +0,0 @@ -# frozen_string_literal: false -# -# 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 - - - -# 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: -# -# require 'forwardable' -# -# class RecordCollection -# attr_accessor :records -# extend Forwardable -# def_delegator :@records, :[], :record_number -# end -# -# We can use the lookup method like so: -# -# r = RecordCollection.new -# r.records = [4,5,6] -# r.record_number(0) # => 4 -# -# 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 # re-open RecordCollection class -# def_delegators :@records, :size, :<<, :map -# end -# -# r = RecordCollection.new -# r.records = [1,2,3] -# r.record_number(0) # => 1 -# r.size # => 3 -# r << 4 # => [1, 2, 3, 4] -# r.map { |x| x * 2 } # => [2, 4, 6, 8] -# -# You can even extend regular objects with Forwardable. -# -# my_hash = Hash.new -# my_hash.extend Forwardable # prepare object for delegation -# my_hash.def_delegator "STDOUT", "puts" # add delegation for STDOUT.puts() -# my_hash.puts "Howdy!" -# -# == Another example -# -# 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 -# -# This should output: -# -# 2 -# 3 -# 4 -# 5 -# 6 -# Ruby -# nil -# -# == Notes -# -# Be advised, RDoc will not detect delegated methods. -# -# +forwardable.rb+ provides single-method delegation via the def_delegator and -# def_delegators methods. For full-class delegation via DelegateClass, see -# +delegate.rb+. -# -module Forwardable - # Version of +forwardable.rb+ - FORWARDABLE_VERSION = "1.1.0" - - FILE_REGEXP = %r"#{Regexp.quote(__FILE__)}" - - @debug = nil - class << self - # If true, <tt>__FILE__</tt> will remain in the backtrace in the event an - # Exception is raised. - 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) - gen = Forwardable._delegator_method(self, accessor, method, ali) - - # If it's not a class or module, it's an instance - (Module === self ? self : singleton_class).module_eval(&gen) - end - - alias delegate instance_delegate - alias def_delegators def_instance_delegators - alias def_delegator def_instance_delegator - - def self._delegator_method(obj, accessor, method, ali) - accessor = accessor.to_s unless Symbol === accessor - - if Module === obj ? - obj.method_defined?(accessor) || obj.private_method_defined?(accessor) : - obj.respond_to?(accessor, true) - accessor = "#{accessor}()" - end - - line_no = __LINE__+1; str = "#{<<-"begin;"}\n#{<<-"end;"}" - begin; - proc do - def #{ali}(*args, &block) - begin - #{accessor} - ensure - $@.delete_if {|s| ::Forwardable::FILE_REGEXP =~ s} if $@ and !::Forwardable::debug - end.__send__ :#{method}, *args, &block - end - end - end; - - RubyVM::InstructionSequence - .compile(str, __FILE__, __FILE__, line_no, - trace_instruction: false, - tailcall_optimization: true) - .eval - end -end - -# 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 used to set up delegation for a Class or Module. -# -# class Implementation -# def self.service -# puts "serviced!" -# end -# end -# -# module Facade -# extend SingleForwardable -# def_delegator :Implementation, :service -# end -# -# Facade.service #=> serviced! -# -# If you want to use both Forwardable and SingleForwardable, you can -# use methods def_instance_delegator and def_single_delegator, etc. -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 - - # :call-seq: - # def_single_delegator(accessor, method, new_name=method) - # - # Defines a method _method_ which delegates to _accessor_ (i.e. it calls - # the method of the same name in _accessor_). If _new_name_ is - # provided, it is used as the name for the delegate method. - def def_single_delegator(accessor, method, ali = method) - gen = Forwardable._delegator_method(self, accessor, method, ali) - - instance_eval(&gen) - end - - alias delegate single_delegate - alias def_delegators def_single_delegators - alias def_delegator def_single_delegator -end |