make 'Pry::Config::Default' less of a special case by adding Pry::Con…

…fig::Lazy

lib/pry/config.rb

@@ -1,6 +1,7 @@
 require_relative 'basic_object'
 class Pry::Config < Pry::BasicObject
   require_relative 'config/behavior'
+  require_relative 'config/lazy'
   require_relative 'config/default'
   require_relative 'config/convenience'
   include Pry::Config::Behavior

lib/pry/config/behavior.rb

@@ -142,7 +142,7 @@ def keys
 
   def eager_load!
     local_last_default = last_default
-    local_last_default.default_keys.each do |key|
+    local_last_default.lazy_keys.each do |key|
       self[key] = local_last_default.public_send(key)
     end
   end

lib/pry/config/default.rb

@@ -1,5 +1,6 @@
 class Pry::Config::Default
   include Pry::Config::Behavior
+  include Pry::Config::Lazy
 
   default = {
     input: proc {
@@ -121,19 +122,9 @@ def initialize
     configure_gist
     configure_history
   end
+  lazy_implement(default)
 
-  default.each do |key, value|
-    define_method(key) do
-      if default[key].equal?(value)
-        default[key] = instance_eval(&value)
-      end
-      default[key]
-    end
-  end
-
-  define_method(:default_keys) { default.keys }
-
-private
+  private
   # TODO:
   # all of this configure_* stuff is a relic of old code.
   # we should try move this code to being command-local.

lib/pry/config/lazy.rb

@@ -0,0 +1,26 @@
+module Pry::Config::Lazy
+  LAZY_KEYS = {}
+  LAZY_KEYS.default_proc = lambda {|h,k| h[k] = [] }
+
+  module ExtendModule
+    def lazy_implement(method_name_to_func)
+      method_name_to_func.each do |method_name, func|
+        define_method(method_name) do
+          if method_name_to_func[method_name].equal?(func)
+            method_name_to_func[method_name] = instance_eval(&func)
+            LAZY_KEYS[self.class] |= method_name_to_func.keys
+          end
+          method_name_to_func[method_name]
+        end
+      end
+    end
+  end
+
+  def self.included(includer)
+    includer.extend(ExtendModule)
+  end
+
+  def lazy_keys
+    LAZY_KEYS[self.class]
+  end
+end