Rename SlotDefinition to Slot

And the derived XXDefinitions to XXSlot

Just to be more consistent
And possibly free the Definition for the Language side

test/slot_machine/instruction/test_argument_transfer.rb

@@ -3,7 +3,7 @@ require_relative "helper"
 module SlotMachine
   class TestArgumentTransfer < SlotMachineInstructionTest
     def instruction
-      receiver = MessageDefinition.new( [:receiver])
+      receiver = MessageSlot.new( [:receiver])
       arg = SlotLoad.new("test", [:message, :caller] , [:message,:type] )
       ArgumentTransfer.new("" , receiver ,[arg])
     end

test/slot_machine/instruction/test_constant_slot.rb

@@ -2,11 +2,11 @@ require_relative "helper"
 
 module SlotMachine
 
-  class TestSlotDefinitionConstant < MiniTest::Test
+  class TestSlotConstant < MiniTest::Test
     def setup
       Parfait.boot!(Parfait.default_test_options)
       @compiler = Risc::FakeCompiler.new
-      @definition = SlotDefinition.for(StringConstant.new("hi") , [])
+      @definition = Slot.for(StringConstant.new("hi") , [])
       @register = @definition.to_register(@compiler , InstructionMock.new)
       @instruction = @compiler.instructions.first
     end
@@ -23,11 +23,11 @@ module SlotMachine
       assert_equal "[StringConstant]" , @definition.to_s
     end
   end
-  class TestSlotDefinitionConstantType < MiniTest::Test
+  class TestSlotConstantType < MiniTest::Test
     def setup
       Parfait.boot!(Parfait.default_test_options)
       @compiler = Risc::FakeCompiler.new
-      @definition = SlotDefinition.for(StringConstant.new("hi") , [:type])
+      @definition = Slot.for(StringConstant.new("hi") , [:type])
       @register = @definition.to_register(@compiler , InstructionMock.new)
       @instruction = @compiler.instructions.first
     end

test/slot_machine/instruction/test_message_slot.rb

@@ -1,10 +1,10 @@
 require_relative "helper"
 
 module SlotMachine
-  class TestSlotDefinitionBasics < MiniTest::Test
+  class TestSlotBasics < MiniTest::Test
 
     def slot(slot = :caller)
-      MessageDefinition.new(slot)
+      MessageSlot.new(slot)
     end
     def test_create_ok1
       assert_equal :message , slot.known_object

test/slot_machine/instruction/test_not_same_check.rb

@@ -3,7 +3,7 @@ require_relative "helper"
 module SlotMachine
   class TestNotSameCheck < SlotMachineInstructionTest
     def instruction
-      target = SlotDefinition.for(:message , :caller)
+      target = Slot.for(:message , :caller)
       NotSameCheck.new(target , target , Label.new("ok" , "target"))
     end
     def test_len

test/slot_machine/instruction/test_slot.rb

@@ -0,0 +1,23 @@
+require_relative "helper"
+
+module SlotMachine
+  class TestSlotBasics < MiniTest::Test
+
+    def slot(slot = :caller)
+      MessageSlot.new(slot)
+    end
+    def test_create_ok1
+      assert_equal :message , slot.known_object
+    end
+    def test_create_ok2
+      assert_equal Array , slot.slots.class
+      assert_equal :caller , slot.slots.first
+    end
+    def test_to_s
+      assert_equal "[message, caller]" , slot.to_s
+    end
+    def test_create_fail_none
+      assert_raises {slot(nil)}
+    end
+  end
+end

test/slot_machine/instruction/test_slot2.rb

@@ -1,11 +1,11 @@
 require_relative "helper"
 
 module SlotMachine
-  class TestSlotDefinitionKnown1 < MiniTest::Test
+  class TestSlotKnown1 < MiniTest::Test
     def setup
       Parfait.boot!(Parfait.default_test_options)
       @compiler = Risc::FakeCompiler.new
-      @definition = MessageDefinition.new( :caller)
+      @definition = MessageSlot.new( :caller)
       @register = @definition.to_register(@compiler , "fake source")
       @instruction = @compiler.instructions.first
     end

test/slot_machine/instruction/test_slot_definition3.rb

@@ -1,27 +0,0 @@
-require_relative "helper"
-
-module SlotMachine
-  class TestSlotDefinitionKnown2 < MiniTest::Test
-    def setup
-      Parfait.boot!(Parfait.default_test_options)
-      @compiler = Risc::FakeCompiler.new
-      @definition = MessageDefinition.new( [:caller , :type])
-      @register = @definition.to_register(@compiler , InstructionMock.new)
-    end
-    def test_def_next_class
-      assert_equal Risc::SlotToReg , @compiler.instructions[1].class
-    end
-    def test_def_next_next_class
-      assert_equal NilClass , @compiler.instructions[2].class
-    end
-    def test_def_next_index
-      assert_equal 0 , @compiler.instructions[1].index
-    end
-    def test_def_next_register
-      assert_equal :r1 , @compiler.instructions[1].register.symbol
-    end
-    def test_def_next_array
-      assert_equal :r1 , @compiler.instructions[1].array.symbol
-    end
-  end
-end

test/slot_machine/instruction/test_truth_check.rb

@@ -3,7 +3,7 @@ require_relative "helper"
 module SlotMachine
   class TestSameCheck < SlotMachineInstructionTest
     def instruction
-      target = MessageDefinition.new( :caller)
+      target = MessageSlot.new( :caller)
       TruthCheck.new(target , Label.new("ok" , "target"))
     end
     def test_len