add branch listener functionaliy

have to store the branches and loop again as labels
dont neccessarily have positions yet

lib/risc/position/branch_listener.rb

@@ -3,12 +3,13 @@ module Risc
   class BranchListener
 
     # initialize with the instruction listener
-    def initialize(listener)
-      @listener = listener
+    def initialize(branch)
+      @branch = branch
     end
 
-
+    # incoming position is the labels
     def position_changed(position)
+      @branch.precheck
     end
 
     # don't react to insertion, as the CodeListener will take care

lib/risc/position/instruction_listener.rb

@@ -88,16 +88,18 @@ module Risc
       raise "Not Binary Code #{code.class}" unless code.is_a?(Parfait::BinaryCode)
       raise "Must init with instruction, not nil" unless instruction
       first = nil
+      branches = []
       while(instruction)
         position = Position.get_or_create(instruction)
         first = position unless first
         position.position_listener( InstructionListener.new( code ) )
-        if instruction.respond_to?(:branch)
-#          label_pos = Position.get(instruction.branch)
-#          label_pos.position_listener( BranchListener.new(il))
-        end
+        branches << instruction if instruction.respond_to?(:branch_to)
         instruction = instruction.next
       end
+      branches.each do |branch|
+        label_pos = Position.get(branch.branch_to)
+        label_pos.position_listener( BranchListener.new(branch) )
+      end
       first
     end
   end

lib/risc/position/position.rb

@@ -220,5 +220,6 @@ module Risc
 end
 require_relative "position_listener"
 require_relative "instruction_listener"
+require_relative "branch_listener"
 require_relative "code_listener"
 require_relative "label_listener"