seperate different Position classes into own files

also tests
and have Position module keep all positions
(singletons should be at module, not class level)

lib/risc/position/instruction_position.rb

@@ -0,0 +1,31 @@
+module Risc
+  module Position
+
+    class InstructionPosition < ObjectPosition
+      attr_reader :instruction , :binary
+      def initialize(instruction, pos , binary)
+        raise "not set " unless binary
+        super(pos)
+        @instruction = instruction
+        @binary = binary
+      end
+
+      def init(at)
+        return unless instruction.next
+        at += instruction.byte_length
+        bin = binary
+        if( 12 == at % 60)
+          at = 12
+          bin = binary.next
+        end
+        Position.set(instruction.next, at , binary)
+      end
+
+      def reset_to(pos)
+        super(pos)
+        #puts "Reset (#{changed}) #{instruction}"
+        init(pos)
+      end
+    end
+  end
+end