1 files changed, 39 insertions, 33 deletions

diff --git a/lib/forwardable.rb b/lib/forwardable.rb
index f5202f9318..175d6d9c6b 100644
--- a/lib/forwardable.rb
+++ b/lib/forwardable.rb
@@ -76,7 +76,7 @@
 #     def_delegators :@q, :clear, :first, :push, :shift, :size
 #   end
 #
-#   q = Queue.new
+#   q = Thread::Queue.new
 #   q.enq 1, 2, 3, 4, 5
 #   q.push 6
 #
@@ -109,11 +109,13 @@
 # +delegate.rb+.
 #
 module Forwardable
-  require 'forwardable/impl'
-
   # Version of +forwardable.rb+
-  VERSION = "1.2.0"
+  VERSION = "1.4.0"
+  VERSION.freeze
+
+  # Version for backward compatibility
   FORWARDABLE_VERSION = VERSION
+  FORWARDABLE_VERSION.freeze
 
   @debug = nil
   class << self
@@ -122,7 +124,8 @@ module Forwardable
   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
+  # symbols.  These symbols correspond to method names, instance variable
+  # names, or constant names (see def_delegator).  The value is
   # the accessor to which the methods will be delegated.
   #
   # :call-seq:
@@ -151,18 +154,21 @@ module Forwardable
   #   def_delegator :@records, :map
   #
   def def_instance_delegators(accessor, *methods)
-    methods.delete("__send__")
-    methods.delete("__id__")
-    for method in methods
+    methods.each do |method|
+      next if /\A__(?:send|id)__\z/ =~ method
       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+.
+  # +accessor.method+.  +accessor+ should be a method name, instance
+  # variable name, or constant name.  Use the full path to the
+  # constant if providing the constant name.
+  # Returns the name of the method defined.
   #
   #   class MyQueue
+  #     CONST = 1
   #     extend Forwardable
   #     attr_reader :queue
   #     def initialize
@@ -170,18 +176,21 @@ module Forwardable
   #     end
   #
   #     def_delegator :@queue, :push, :mypush
+  #     def_delegator 'MyQueue::CONST', :to_i
   #   end
   #
   #   q = MyQueue.new
   #   q.mypush 42
   #   q.queue    #=> [42]
   #   q.push 23  #=> NoMethodError
+  #   q.to_i     #=> 1
   #
   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)
+    mod = Module === self ? self : singleton_class
+    mod.module_eval(&gen)
   end
 
   alias delegate instance_delegate
@@ -195,36 +204,33 @@ module Forwardable
     if Module === obj ?
          obj.method_defined?(accessor) || obj.private_method_defined?(accessor) :
          obj.respond_to?(accessor, true)
-      accessor = "#{accessor}()"
+      accessor = "(#{accessor}())"
     end
 
-    method_call = ".__send__(:#{method}, *args, &block)"
-    if _valid_method?(method)
+    args = RUBY_VERSION >= '2.7' ? '...' : '*args, &block'
+    method_call = ".__send__(:#{method}, #{args})"
+    if method.match?(/\A[_a-zA-Z]\w*[?!]?\z/)
       loc, = caller_locations(2,1)
       pre = "_ ="
       mesg = "#{Module === obj ? obj : obj.class}\##{ali} at #{loc.path}:#{loc.lineno} forwarding to private method "
-      method_call = "#{<<-"begin;"}\n#{<<-"end;".chomp}"
-        begin;
-          unless defined? _.#{method}
-            ::Kernel.warn #{mesg.dump}"\#{_.class}"'##{method}', uplevel: 1
-            _#{method_call}
-          else
-            _.#{method}(*args, &block)
-          end
-        end;
+      method_call = <<~RUBY.chomp
+        if defined?(_.#{method})
+          _.#{method}(#{args})
+        else
+          ::Kernel.warn #{mesg.dump}"\#{_.class}"'##{method}', uplevel: 1
+          _#{method_call}
+        end
+      RUBY
     end
 
-    _compile_method("#{<<-"begin;"}\n#{<<-"end;"}", __FILE__, __LINE__+1)
-    begin;
+    eval(<<~RUBY, nil, __FILE__, __LINE__ + 1)
       proc do
-        def #{ali}(*args, &block)
-          #{pre}
-          begin
-            #{accessor}
-          end#{method_call}
+        def #{ali}(#{args})
+          #{pre}#{accessor}
+          #{method_call}
         end
       end
-    end;
+    RUBY
   end
 end
 
@@ -283,9 +289,8 @@ module SingleForwardable
   #   def_delegator :@records, :map
   #
   def def_single_delegators(accessor, *methods)
-    methods.delete("__send__")
-    methods.delete("__id__")
-    for method in methods
+    methods.each do |method|
+      next if /\A__(?:send|id)__\z/ =~ method
       def_single_delegator(accessor, method)
     end
   end
@@ -296,6 +301,7 @@ module SingleForwardable
   # 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.
+  # Returns the name of the method defined.
   def def_single_delegator(accessor, method, ali = method)
     gen = Forwardable._delegator_method(self, accessor, method, ali)