gets the if coded, but test fail die to instruction being a graph now

lib/ast/if_expression.rb

@@ -3,12 +3,27 @@ module Ast
 #    attr_reader  :cond, :if_true, :if_false
     def compile frame , method
       is = cond.compile(frame , method)
-#      is.is_false(frame,method)
+      #      is.is_false(frame,method)
+      # TODO should/will use different branches for different conditions. 
+      branch = Virtual::ImplicitBranch.new
+      method.add branch
       last = is
       if_true.each do |part|
         last = part.compile(frame,method )
         raise part.inspect if last.nil?
       end
+      label = Virtual::Label.new
+      method.add label
+      branch.swap
+      method.current = branch
+      if_false.each do |part|
+        last = part.compile(frame,method )
+        raise part.inspect if last.nil?
+      end
+      method.add label
+      branch.swap
+      method.current = label
+      #TODO should return the union of the true and false types
       last
     end
     def old