fx.rb in facets-2.9.0.pre.1

- old
+ new

@@ -1,20 +1,36 @@
-begin
-  require 'enumerator' #if RUBY_VERSION < 1.9
-  # for Ruby 1.8 -> 1.9 transition
-  Enumerator = Enumerable::Enumerator unless defined? ::Enumerator
-rescue LoadError # Ruby 1.9 already has it built-in.
+# for Ruby 1.8 -> 1.9 transition
+unless defined?(::Enumerator)
+  begin
+    require 'enumerator'
+    Enumerator = Enumerable::Enumerator unless defined? ::Enumerator
+  rescue LoadError # Ruby 1.9 already has it built-in.
+  end
 end
 
 require 'facets/functor'
 
 class Enumerator
 
   #
   def fx
-    Functor.new do |op, *a|
-      each{ |e| e.send(op, *a) }
-    end
+    Functor.new(&method(:fx_send).to_proc)
   end
+
+  private
+
+  #
+  def fx_send(op, *a, &b)
+    map{ |e| e.send(op, *a, &b) }
+  end
+
+  ## TODO: When no longer needed to support 1.8.6 we can use:
+  ##
+  ## #
+  ## def fx
+  ##   Functor.new do |op, *a, &b|
+  ##     map{ |e| e.send(op, *a, &b) }
+  ##   end
+  ## end
 
 end
 