(in-package :data-lens.transducers.internals)
 
 (defgeneric unwrap (it obj)
   (:method (it obj) obj))
 (defgeneric init (it))
 (defgeneric stepper (it))
 
 (defgeneric reduce-generic (seq func init)
   (:method ((seq sequence) (func function) init)
     (reduce func seq :initial-value init))
   (:method ((seq sequence) (func symbol) init)
     (reduce func seq :initial-value init))
   (:method (seq (func symbol) init)
     (reduce-generic seq
                     (symbol-function func)
                     init))
   (:method ((seq hash-table) (func function) init)
     (let ((acc init))
       (maphash (lambda (k v)
                  (setf acc (funcall func acc (list k v))))
                seq)
       acc)))