add data objects

marker class (may change) to be able to check access

lib/parfait/data_object.rb

@@ -0,0 +1,63 @@
+#
+#
+# In rubyx everything truely is an object. (most smalltalk/ruby systems use a union
+# for integers/pointers that are called objects, but are really very different)
+#
+# Objects have type as their first member. No exception.
+#
+# So where is the data? In DataObjects. DataObjects are opague carriers of data.
+# Opague to rubyx that is. There is no way to get at it or pass the data around.
+#
+# To use Data, Risc instructions have to be used. Luckily there is not soo much one
+# actually wants to do with data, moving it between DataObject , comparing and
+# logical and math operation that are bundled into the OperatorInstruction.
+#
+# For safe access the access code needs to know the length of the data, which is
+# encoded in the class/type name. Ie An Integer derives from Data2, which is 2 long
+# (minus one for the type, so exactly the one word for the integer)
+#
+# DataObjects still have a type, and so can have objects before the data starts
+#
+# A marker class
+module Parfait
+  class DataObject < Object
+    def initialize
+      @memory = []
+    end
+    def data_length
+      raise "called #{self}"
+    end
+    def data_start
+      return type.length
+    end
+
+    # 1 -based index
+    def get_internal_word(index)
+      @memory[index]
+    end
+
+    # 1 -based index
+    def set_internal_word(index , value)
+      raise "Word[#{index}] = nil" if( value.nil? )
+      @memory[index] = value
+      value
+    end
+  end
+
+  class Data2 < DataObject
+    def data_length
+      1
+    end
+  end
+
+  class Data8 < DataObject
+    def data_length
+      7
+    end
+  end
+  class Data16 < DataObject
+    def data_length
+      15
+    end
+  end
+end