@@ -179,6 +179,11 @@

   (lambda (seq)

     (map 'list selector seq)))

+(defun tap (cb)

+  (lambda (it)

+    (prog1 it

+      (funcall cb it))))

+

 (defun slice (start &optional end)

   (lambda (it)

     (subseq it start end)))

@@ -21,7 +21,8 @@

            #:transform-elt #:denest #:op #:defalias #:<> #:<>1 #:== #:•

            #:∘ #:suffixp #:functionalize #:inc #:group-by #:keys

            #:conj #:disj #:delay #:of-type #:transform #:calling*

-           #:calling))

+           #:calling

+           #:tap))

 (defpackage :data-lens.transducers.internals

   (:use :cl)