start BranchListener

but on hold, since it needs positions before we have them
Must create them during collection phase

lib/risc/instructions/branch.rb

@@ -23,6 +23,10 @@ module Risc
     end
     alias :inspect :to_s
 
+    # if branch is implemented it must return the label it branches to
+    def branch
+      label
+    end
   end
 
   # dynamic version of an Branch branch that jumps to the contents

lib/risc/position/branch_listener.rb

@@ -0,0 +1,22 @@
+module Risc
+
+  class BranchListener
+
+    # initialize with the instruction listener
+    def initialize(listener)
+      @listener = listener
+    end
+
+
+    def position_changed(position)
+    end
+
+    # don't react to insertion, as the CodeListener will take care
+    def position_inserted(position)
+    end
+
+    # dont react, as we do the work in position_changed
+    def position_changing(position , to)
+    end
+  end
+end

lib/risc/position/instruction_listener.rb

@@ -13,7 +13,7 @@ module Risc
   # the same BinaryCode, or else move it and the code along
   #
   class InstructionListener
-    attr_reader :binary
+    attr_reader :binary , :index
 
     def initialize(binary)
       @binary = binary
@@ -91,7 +91,12 @@ module Risc
       while(instruction)
         position = Position.new(instruction , -1)
         first = position unless first
-        position.position_listener(InstructionListener.new( code ))
+        il = InstructionListener.new( code )
+        position.position_listener(il)
+        if instruction.respond_to?(:branch)
+#          label_pos = Position.get(instruction.branch)
+#          label_pos.position_listener( BranchListener.new(il)) 
+        end
         instruction = instruction.next
       end
       first