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Diffstat (limited to 'ruby_1_8_6/lib/forwardable.rb')
| -rw-r--r-- | ruby_1_8_6/lib/forwardable.rb | 218 |
1 files changed, 0 insertions, 218 deletions
diff --git a/ruby_1_8_6/lib/forwardable.rb b/ruby_1_8_6/lib/forwardable.rb deleted file mode 100644 index b6344cd4f6..0000000000 --- a/ruby_1_8_6/lib/forwardable.rb +++ /dev/null @@ -1,218 +0,0 @@ -# = forwardable - Support for the Delegation Pattern -# -# $Release Version: 1.1$ -# $Revision$ -# $Date$ -# by Keiju ISHITSUKA(keiju@ishitsuka.com) -# -# 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. You can use Forwardable to setup this delegation at the class -# level, or SingleForwardable to handle it at the object level. -# -# == 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 prefered 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 -# -# printer = String.new -# printer.extend SingleForwardable # 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 -# -# Also see the example at forwardable.rb. -# -module Forwardable - - @debug = nil - class<<self - # force Forwardable to show up in stack backtraces of delegated methods - attr_accessor :debug - 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 - # - # See the examples at Forwardable and forwardable.rb. - # - def def_instance_delegators(accessor, *methods) - for method in methods - def_instance_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. - # - # See the examples at Forwardable and forwardable.rb. - # - def def_instance_delegator(accessor, method, ali = method) - accessor = accessor.id2name if accessor.kind_of?(Integer) - method = method.id2name if method.kind_of?(Integer) - ali = ali.id2name if ali.kind_of?(Integer) - - module_eval(<<-EOS, "(__FORWARDABLE__)", 1) - def #{ali}(*args, &block) - begin - #{accessor}.__send__(:#{method}, *args, &block) - rescue Exception - $@.delete_if{|s| /^\\(__FORWARDABLE__\\):/ =~ s} unless Forwardable::debug - Kernel::raise - end - end - EOS - end - - alias def_delegators def_instance_delegators - alias def_delegator def_instance_delegator -end - -# -# The SingleForwardable module provides delegation of specified -# methods to a designated object, using the methods #def_delegator -# and #def_delegators. This module is similar to Forwardable, but it works on -# objects themselves, instead of their defining classes. -# -# Also see the example at forwardable.rb. -# -module SingleForwardable - # - # Shortcut for defining multiple delegator methods, but with no - # provision for using a different name. The following two code - # samples have the same effect: - # - # single_forwardable.def_delegators :@records, :size, :<<, :map - # - # single_forwardable.def_delegator :@records, :size - # single_forwardable.def_delegator :@records, :<< - # single_forwardable.def_delegator :@records, :map - # - # See the example at forwardable.rb. - # - def def_singleton_delegators(accessor, *methods) - for method in methods - def_singleton_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. - # - # See the example at forwardable.rb. - # - def def_singleton_delegator(accessor, method, ali = method) - accessor = accessor.id2name if accessor.kind_of?(Integer) - method = method.id2name if method.kind_of?(Integer) - ali = ali.id2name if ali.kind_of?(Integer) - - instance_eval(<<-EOS, "(__FORWARDABLE__)", 1) - def #{ali}(*args, &block) - begin - #{accessor}.__send__(:#{method}, *args,&block) - rescue Exception - $@.delete_if{|s| /^\\(__FORWARDABLE__\\):/ =~ s} unless Forwardable::debug - Kernel::raise - end - end - EOS - end - - alias def_delegators def_singleton_delegators - alias def_delegator def_singleton_delegator -end |