anchor.diff:  (defmethod print-object ((obj clclojure.cowmap::cowmap) stream)
     (common-utils::print-map (cowmap-table obj) stream))
   
  -(defmacro when-let [binding & args]
  -  )
  +;; (defmacro when-let [binding & args]
  +;;   )
   ;;need to implement arrayseq...
   (defn seq [coll] (-seq coll))
   
  
positive.code: (defgeneric destructure (bindings))
  
  ;;a single function definition
  (defstruct fn-def args body)
  ;;a macro definition -- later
  (defstruct macro-def name args body)
  
  ;;At compile-time, [x y] -> (persistent-vector x y).
  ;;This is upsetting us...
  
negative.code:  IMapEntry
   (-key [coll] (first coll))
   (-val [coll] (second coll))
   ISeq
   (-first [coll]  (sequences::first coll))
   (-rest  [coll]  (sequences::rest coll))
   )
  
  (extend-type
  