anchor.diff:           (new-value  (dump-resultset data-stream
                                        resultset
                                        idx
  -                                     comparator)))
  +                                     comparator
  +                                     progress)))
       (list :table table
             :columns columns
             :incremental incremental
  
positive.code:             :limit limit
              :output-path output-path
              :read-receipt-path read-receipt-path
              :write-receipt-path write-receipt-path))))
  
  (defun dump-resultset (stream resultset incremental comparator)
    (iter (for row = (next-row resultset))
          (while row)
          (format stream #?"~{~A~^\t~}~%" row)
          (when incremental
            (for val = (elt row incremental))
            (reducing val by (lambda (a b) (if (funcall comparator a b) b a))))))
  
  (defparameter *type-comparator-map*
    (plist-hash-table (list :int      #'<
  
negative.code:                                             :limit limit
                                              :columns columns
                                              :incremental incremental
                                              :last-value last-value
                                              :progress progress)))
                (when write-receipt-path
                  (write-receipt write-receipt-path new-receipt)))))))))
  
  