moving know_object out of the base class

object is only common to constant and object slots (which should be unified)
On the way to making the array recursive

lib/slot_machine/constant_slot.rb

@@ -1,22 +1,15 @@
 module SlotMachine
   class ConstantSlot < Slot
-    # get the right definition, depending on the object
-    def self.for(object , slots)
-      case object
-      when :message
-        MessageSlot.new(slots)
-      when Constant
-        ConstantSlot.new(object , slots)
-      else
-        Slot.new(object,slots)
-      end
-    end
+
+
+    attr_reader :known_object
 
     def initialize( object , slots)
-      super(object, slots)
+      super(slots)
+      @known_object = object
+      raise "Not known #{slots}" unless object
     end
 
-
     def known_name
       known_object.class.short_name
     end
@@ -31,18 +24,15 @@ module SlotMachine
         type = :Object
       end
       right = compiler.use_reg( type )
-      case known_object
-      when Constant
-        parfait = known_object.to_parfait(compiler)
-        const = Risc.load_constant(source, parfait , right)
-        compiler.add_code const
-        if slots.length == 1
-          raise "only type allowed for constants, not #{slots[0]}" unless slots[0] == :type
-          compiler.add_code Risc::SlotToReg.new( source , right , Parfait::TYPE_INDEX, right)
-        end
-        raise "Can't have slots into Constants #{slots}" if slots.length > 1
+      parfait = known_object.to_parfait(compiler)
+      const = Risc.load_constant(source, parfait , right)
+      compiler.add_code const
+      if slots.length == 1
+        raise "only type allowed for constants, not #{slots[0]}" unless slots[0] == :type
+        compiler.add_code Risc::SlotToReg.new( source , right , Parfait::TYPE_INDEX, right)
       end
-        return const.register
+      raise "Can't have slots into Constants #{slots}" if slots.length > 1
+      return const.register
     end
 
   end

lib/slot_machine/message_slot.rb

@@ -2,12 +2,13 @@ module SlotMachine
   class MessageSlot < Slot
 
     def initialize(slots)
-      super(:message , slots)
+      super(slots)
     end
 
     def known_name
       :message
     end
+    alias :known_object :known_name 
 
     # load the slots into a register
     # the code is added to compiler

lib/slot_machine/object_slot.rb

@@ -1,8 +1,12 @@
 module SlotMachine
   class ObjectSlot < Slot
 
+    attr_reader :known_object
+
     def initialize( object , slots)
-      super(object , slots )
+      super(slots)
+      @known_object = object
+      raise "Not known #{slots}" unless object
     end
 
     def known_name

lib/slot_machine/slot.rb

@@ -29,17 +29,16 @@ module SlotMachine
       end
     end
 
-    attr_reader :known_object , :slots
+    attr_reader :slots
     # is an array of symbols, that specifies the first the object, and then the Slot.
     # The first element is either a known type name (Capitalized symbol of the class name) ,
     # or the symbol :message
     # And subsequent symbols must be instance variables on the previous type.
     # Examples:  [:message , :receiver] or [:Space , :next_message]
-    def initialize( object , slots)
+    def initialize( slots)
       raise "No slots #{object}" unless slots
       slots = [slots] unless slots.is_a?(Array)
-      @known_object , @slots = object , slots
-      raise "Not known #{slots}" unless object
+      @slots =  slots
     end
 
     def to_s

test/slot_machine/helper.rb

@@ -1 +1,9 @@
 require_relative '../helper'
+
+module SlotMachine
+  class InstructionMock < Instruction
+    def initialize
+      super("mocking")
+    end
+  end
+end

test/slot_machine/instruction/helper.rb

@@ -1,11 +1,6 @@
 require_relative '../helper'
 
 module SlotMachine
-  class InstructionMock < Instruction
-    def initialize
-      super("mocking")
-    end
-  end
 
   # Most SlotMachineInstructionTests test the risc instructions of the slot instruction
   # quite carefully, ie every instruction, every register.