(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)))