More tweaks to example

README.org

@@ -4,7 +4,9 @@ This library provides a language for expressing data manipulations as
 the composition of more primitive operations.
 
 #+BEGIN_SRC lisp
-  DATA-LENS> (funcall (on (compress-runs :collector 'combine-matching-lists)
+  DATA-LENS> (funcall (on (alexandria:compose
+                           (over (transform-tail (over (slice 1))))
+                           (compress-runs :collector 'combine-matching-lists))
                           (alexandria:compose 
                            (over (data-lens:juxt
                                   (data-lens:element 0)

lens.lisp

@@ -102,6 +102,15 @@
   (lambda (seq)
     (map 'list selector seq)))
 
+(defun slice (start &optional end)
+  (lambda (it)
+    (subseq it start end)))
+
+(defun-ct transform-tail (fun)
+  (lambda (it)
+    (list* (car it)
+           (funcall fun (cdr it)))))
+
 (defun-ct key-transform (fun key-get key-set)
   (lambda (it)
     (let ((key-val (funcall key-get it)))