fold position module and object position

simpler that way, aslo code is moving to listners

lib/risc/position/position.rb

@@ -1,3 +1,5 @@
+require "util/eventable"
+
 module Risc
   # Positions are very different during compilation and run-time.
   # At run-time they are inherrent to the object, and fixed.
@@ -14,10 +16,50 @@ module Risc
   # While the (different)Position objects transmit the change that (re) positioning
   # entails to affected objects.
 
-  module Position
+  class Position
     include Util::Logging
     log_level :info
 
+    include Util::Eventable
+
+    attr_reader :at , :object
+
+    # initialize with a given object, first parameter
+    # The object ill be the key in global position map
+    # Give an integer as the actual position, where -1
+    # which means no legal position known
+    def initialize(object , pos )
+      @at = pos
+      @object = object
+      Position.set_to(self , pos)
+    end
+
+    #look for InstructionListener and return its code if found
+    def get_code
+      listener = event_table.find{|one| one.class == InstructionListener}
+      return nil unless listener
+      listener.code
+    end
+
+    def +(offset)
+      offset = offset.at if offset.is_a?(Position)
+      @at + offset
+    end
+
+    def -(offset)
+      offset = offset.at if offset.is_a?(Position)
+      @at - offset
+    end
+    def to_s
+      "0x#{@at.to_s(16)}"
+    end
+
+    def next_slot
+      return -1 if at < 0
+      at + object.byte_length
+    end
+
+    ## class level forward and reverse cache
     @positions = {}
     @reverse_cache = {}
 
@@ -41,7 +83,7 @@ module Risc
     def self.get(object)
       pos = self.positions[object]
       if pos == nil
-        str = "position accessed but not set, "
+        str = "position accessed but not initialized, "
         str += "0x#{object.object_id.to_s(16)}\n"
         str += "for #{object.class} "
         str += "byte_length #{object.byte_length}" if object.respond_to?(:byte_length)
@@ -51,16 +93,11 @@ module Risc
       pos
     end
 
-    def self.reset(obj)
-      old = self.get(obj)
-      old.reset_to( old.at )
-    end
-
     def self.set_to( position , to)
-      postest = Position.positions[position.object] unless to < 0 
+      postest = Position.positions[position.object] unless to < 0
       raise "Mismatch #{position}" if postest and postest != position
       @reverse_cache.delete(position.at) unless position.object.is_a? Label
-      testing = self.at( position.at ) if position.at >= 0
+      testing = self.at( position.at ) unless position.at < 0
       if testing and testing.class != position.class
         raise "Mismatch (at #{pos.to_s(16)}) was:#{position} #{position.class} #{position.object} , should #{testing}#{testing.class}"
       end
@@ -71,7 +108,6 @@ module Risc
     end
   end
 end
-require_relative "object_position"
 require_relative "object_listener"
 require_relative "instruction_listener"
 require_relative "code_listener"