diff options
Diffstat (limited to 'lib/delegate.rb')
| -rw-r--r-- | lib/delegate.rb | 165 |
1 files changed, 96 insertions, 69 deletions
diff --git a/lib/delegate.rb b/lib/delegate.rb index f2b1388107..a5ae605e9e 100644 --- a/lib/delegate.rb +++ b/lib/delegate.rb @@ -1,3 +1,4 @@ +# frozen_string_literal: true # = delegate -- Support for the Delegation Pattern # # Documentation by James Edward Gray II and Gavin Sinclair @@ -17,15 +18,12 @@ # yourself needing this control, have a look at Forwardable which is also in # the standard library. It may suit your needs better.) # -# SimpleDelegator's implementation serves as a nice example if the use of +# SimpleDelegator's implementation serves as a nice example of the use of # Delegator: # -# class SimpleDelegator < Delegator -# def initialize(obj) -# super # pass obj to Delegator constructor, required -# @delegate_sd_obj = obj # store obj for future use -# end +# require 'delegate' # +# class SimpleDelegator < Delegator # def __getobj__ # @delegate_sd_obj # return object we are delegating to, required # end @@ -41,14 +39,16 @@ # Be advised, RDoc will not detect delegated methods. # class Delegator < BasicObject + VERSION = "0.2.0" + kernel = ::Kernel.dup kernel.class_eval do alias __raise__ raise - [:to_s,:inspect,:=~,:!~,:===,:<=>,:eql?,:hash].each do |m| + [:to_s, :inspect, :=~, :!~, :===, :<=>, :hash].each do |m| undef_method m end private_instance_methods.each do |m| - if /\Ablock_given\?\z|iterator\?\z|\A__.*__\z/ =~ m + if /\Ablock_given\?\z|\Aiterator\?\z|\A__.*__\z/ =~ m next end undef_method m @@ -64,8 +64,8 @@ class Delegator < BasicObject ## # :method: raise - # Use __raise__ if your Delegator does not have a object to delegate the - # raise method call. + # Use #__raise__ if your Delegator does not have a object to delegate the + # #raise method call. # # @@ -79,19 +79,16 @@ class Delegator < BasicObject # # Handles the magic of delegation through \_\_getobj\_\_. # - def method_missing(m, *args, &block) + ruby2_keywords def method_missing(m, *args, &block) r = true target = self.__getobj__ {r = false} - begin - if r && target.respond_to?(m) - target.__send__(m, *args, &block) - elsif ::Kernel.respond_to?(m, true) - ::Kernel.instance_method(m).bind(self).(*args, &block) - else - super(m, *args, &block) - end - ensure - $@.delete_if {|t| %r"\A#{Regexp.quote(__FILE__)}:(?:#{[__LINE__-7, __LINE__-5, __LINE__-3].join('|')}):"o =~ t} if $@ + + if r && target_respond_to?(target, m, false) + target.__send__(m, *args, &block) + elsif ::Kernel.method_defined?(m) || ::Kernel.private_method_defined?(m) + ::Kernel.instance_method(m).bind_call(self, *args, &block) + else + super(m, *args, &block) end end @@ -102,14 +99,31 @@ class Delegator < BasicObject def respond_to_missing?(m, include_private) r = true target = self.__getobj__ {r = false} - r &&= target.respond_to?(m, include_private) - if r && include_private && !target.respond_to?(m, false) - warn "#{caller(3)[0]}: delegator does not forward private method \##{m}" + r &&= target_respond_to?(target, m, include_private) + if r && include_private && !target_respond_to?(target, m, false) + warn "delegator does not forward private method \##{m}", uplevel: 3 return false end r end + KERNEL_RESPOND_TO = ::Kernel.instance_method(:respond_to?) + private_constant :KERNEL_RESPOND_TO + + # Handle BasicObject instances + private def target_respond_to?(target, m, include_private) + case target + when Object + target.respond_to?(m, include_private) + else + if KERNEL_RESPOND_TO.bind_call(target, :respond_to?) + target.respond_to?(m, include_private) + else + KERNEL_RESPOND_TO.bind_call(target, m, include_private) + end + end + end + # # Returns the methods available to this delegate object as the union # of this object's and \_\_getobj\_\_ methods. @@ -153,6 +167,14 @@ class Delegator < BasicObject end # + # Returns true if two objects are considered of equal value. + # + def eql?(obj) + return true if obj.equal?(self) + obj.eql?(__getobj__) + end + + # # Delegates ! to the \_\_getobj\_\_ # def ! @@ -182,7 +204,7 @@ class Delegator < BasicObject ivars = instance_variables.reject {|var| /\A@delegate_/ =~ var} [ :__v2__, - ivars, ivars.map{|var| instance_variable_get(var)}, + ivars, ivars.map {|var| instance_variable_get(var)}, __getobj__ ] end @@ -193,15 +215,15 @@ class Delegator < BasicObject def marshal_load(data) version, vars, values, obj = data if version == :__v2__ - vars.each_with_index{|var, i| instance_variable_set(var, values[i])} + vars.each_with_index {|var, i| instance_variable_set(var, values[i])} __setobj__(obj) else __setobj__(data) end end - def initialize_clone(obj) # :nodoc: - self.__setobj__(obj.__getobj__.clone) + def initialize_clone(obj, freeze: nil) # :nodoc: + self.__setobj__(obj.__getobj__.clone(freeze: freeze)) end def initialize_dup(obj) # :nodoc: self.__setobj__(obj.__getobj__.dup) @@ -209,39 +231,16 @@ class Delegator < BasicObject private :initialize_clone, :initialize_dup ## - # :method: trust - # Trust both the object returned by \_\_getobj\_\_ and self. - # - - ## - # :method: untrust - # Untrust both the object returned by \_\_getobj\_\_ and self. - # - - ## - # :method: taint - # Taint both the object returned by \_\_getobj\_\_ and self. - # - - ## - # :method: untaint - # Untaint both the object returned by \_\_getobj\_\_ and self. - # - - ## # :method: freeze # Freeze both the object returned by \_\_getobj\_\_ and self. # - - [:trust, :untrust, :taint, :untaint, :freeze].each do |method| - define_method method do - __getobj__.send(method) - super() - end + def freeze + __getobj__.freeze + super() end @delegator_api = self.public_instance_methods - def self.public_api # :nodoc: + def self.public_api # :nodoc: @delegator_api end end @@ -258,6 +257,8 @@ end # end # end # +# require 'delegate' +# # class UserDecorator < SimpleDelegator # def birth_year # born_on.year @@ -312,7 +313,7 @@ end # Non-Nil: 7 # Unique: 6 # -class SimpleDelegator<Delegator +class SimpleDelegator < Delegator # Returns the current object method calls are being delegated to. def __getobj__ unless defined?(@delegate_sd_obj) @@ -345,12 +346,8 @@ end def Delegator.delegating_block(mid) # :nodoc: lambda do |*args, &block| target = self.__getobj__ - begin - target.__send__(mid, *args, &block) - ensure - $@.delete_if {|t| /\A#{Regexp.quote(__FILE__)}:#{__LINE__-2}:/o =~ t} if $@ - end - end + target.__send__(mid, *args, &block) + end.ruby2_keywords end # @@ -363,6 +360,14 @@ end # end # end # +# or: +# +# MyClass = DelegateClass(ClassToDelegateTo) do # Step 1 +# def initialize +# super(obj_of_ClassToDelegateTo) # Step 2 +# end +# end +# # Here's a sample of use from Tempfile which is really a File object with a # few special rules about storage location and when the File should be # deleted. That makes for an almost textbook perfect example of how to use @@ -386,13 +391,15 @@ end # # ... # end # -def DelegateClass(superclass) +def DelegateClass(superclass, &block) klass = Class.new(Delegator) - methods = superclass.instance_methods - methods -= ::Delegator.public_api - methods -= [:to_s,:inspect,:=~,:!~,:===] + ignores = [*::Delegator.public_api, :to_s, :inspect, :=~, :!~, :===] + protected_instance_methods = superclass.protected_instance_methods + protected_instance_methods -= ignores + public_instance_methods = superclass.public_instance_methods + public_instance_methods -= ignores klass.module_eval do - def __getobj__ # :nodoc: + def __getobj__ # :nodoc: unless defined?(@delegate_dc_obj) return yield if block_given? __raise__ ::ArgumentError, "not delegated" @@ -403,15 +410,35 @@ def DelegateClass(superclass) __raise__ ::ArgumentError, "cannot delegate to self" if self.equal?(obj) @delegate_dc_obj = obj end - methods.each do |method| + protected_instance_methods.each do |method| + define_method(method, Delegator.delegating_block(method)) + protected method + end + public_instance_methods.each do |method| define_method(method, Delegator.delegating_block(method)) end end klass.define_singleton_method :public_instance_methods do |all=true| - super(all) - superclass.protected_instance_methods + super(all) | superclass.public_instance_methods end klass.define_singleton_method :protected_instance_methods do |all=true| super(all) | superclass.protected_instance_methods end + klass.define_singleton_method :instance_methods do |all=true| + super(all) | superclass.instance_methods + end + klass.define_singleton_method :public_instance_method do |name| + super(name) + rescue NameError + raise unless self.public_instance_methods.include?(name) + superclass.public_instance_method(name) + end + klass.define_singleton_method :instance_method do |name| + super(name) + rescue NameError + raise unless self.instance_methods.include?(name) + superclass.instance_method(name) + end + klass.module_eval(&block) if block return klass end |