@@ -1 +1,3 @@

 *.fasl

+*.*x*fsl

+*~

@@ -20,7 +20,9 @@

            #:of-max-length

            #:transform-head

            #:maximizing

-           #:zipping))

+           #:zipping

+           #:applying

+           #:transform-elt))

 (in-package :data-lens)

 (declaim 

@@ -163,6 +165,12 @@

     (list* (car it)

            (funcall fun (cdr it)))))

+(defun-ct transform-elt (elt fun)

+  (lambda (it)

+    (append (subseq it 0 elt)

+            (funcall fun (nth elt it))

+            (subseq it (1+ elt)))))

+

 (defun-ct key-transform (fun key-get key-set)

   (lambda (it)

     (let ((key-val (funcall key-get it)))

@@ -214,6 +222,11 @@

   (lambda (seq)

     (map result-type fun seq)))

+(defmacro applying (fun &rest args)

+  (alexandria:with-gensyms (seq)

+    `(lambda (,seq)

+       (apply ,fun ,@args ,seq))))

+

 (defun-ct on (fun key)

   (lambda (it)

     (funcall fun (funcall key it))))