removed blocks and moved to labels

somewhat easier to understand the code as a linked list
relatively painless change, considering

lib/register/instructions/branch.rb

@@ -6,14 +6,22 @@ module Register
     def initialize source , to
       super(source)
       raise "No block" unless to
-      @block = to
+      @label = to
     end
-    attr_reader :block
+    attr_reader :label
 
     def to_s
-      "#{self.class.name}: #{block.name}"
+      "#{self.class.name}: #{label.name}"
     end
     alias :inspect :to_s
+
+    def length labels = []
+      super(labels) + self.label.length(labels)
+    end
+
+    def to_ac labels = []
+      super(labels) + self.label.to_ac(labels)
+    end
   end
 
   class IsZero < Branch

lib/register/instructions/label.rb

@@ -0,0 +1,34 @@
+module Register
+
+  # A label is a placeholder for it's next Instruction
+  # It's function is not to turn into code, but to be a valid brnch target
+  #
+  # So branches and Labels are pairs, fan out, fan in
+  #
+  #
+
+  class Label < Instruction
+    def initialize source , name , nekst = nil
+      super(source , nekst)
+      @name = name
+    end
+    attr_reader :name
+
+    def to_s
+      "Label: #{@name} (#{self.next.class})"
+    end
+
+    def to_ac labels = []
+      return [] if labels.include?(self)
+      labels << self
+      self.next.to_ac(labels)
+    end
+
+    def length labels = []
+      return 0 if labels.include?(self)
+      labels << self
+      1 + self.next.length(labels)
+    end
+
+  end
+end