diff --git a/package.lisp b/package.lisp
index 4ee82d6..8d3e3bc 100644
--- a/package.lisp
+++ b/package.lisp
@@ -39,4 +39,9 @@
            #:mv-selecting
            #:hash-table-select
            #:mv-filtering
-           #:lazy-sequence))
+           #:lazy-sequence
+           #:compressing-runs
+           #:mapcatting
+           #:iota
+           #:repeating
+           #:repeating*))
diff --git a/t/transducer.lisp b/t/transducer.lisp
index 6e29fcb..26f5147 100644
--- a/t/transducer.lisp
+++ b/t/transducer.lisp
@@ -1,4 +1,4 @@
-(defpackage :fwoar.lisp-sandbox.t.transducer
+(defpackage :data-lens.t.transducers
   (:use :cl )
   (:export ))
 (in-package :fwoar.lisp-sandbox.t.transducer)
@@ -20,6 +20,96 @@
                                                   'data-lens.transducers:list-builder
                                                   '(1 2 3)))))
 
+(5am:def-test mv-selecting (:suite :data-lens.transducers)
+  (5am:is (equal '(2 4)
+                 (data-lens.transducers:transduce (data-lens.transducers:mv-selecting
+                                                   (lambda (it)
+                                                     (values (1+ it) (oddp it))))
+                                                  'data-lens.transducers:list-builder
+                                                  '(1 2 3))))
+  (5am:is (equal '(a b)
+                 (data-lens.transducers:transduce (data-lens.transducers:hash-table-select
+                                                   (alexandria:alist-hash-table
+                                                    '((1 . a)
+                                                      (2 . b))))
+                                                  'data-lens.transducers:list-builder
+                                                  '(1 2)))))
+
+(5am:def-test filtering (:suite :data-lens.transducers)
+  (5am:is (equal '(1 3)
+                 (data-lens.transducers:transduce (data-lens.transducers:filtering 'oddp)
+                                                  'data-lens.transducers:list-builder
+                                                  '(1 2 3))))
+  (5am:is (equal '(1 2)
+                 (data-lens.transducers:transduce (data-lens.transducers:mv-filtering
+                                                   'gethash (alexandria:alist-hash-table
+                                                             '((1 . a)
+                                                               (2 . b))))
+                                                  'data-lens.transducers:list-builder
+                                                  '(1 2 3)))))
+
+(5am:def-test deduping (:suite :data-lens.transducers)
+  (5am:is (equal '(1 2 1 2 3 4 1)
+                 (data-lens.transducers:transduce (data-lens.transducers:deduping)
+                                                  'data-lens.transducers:list-builder
+                                                  '(1 1 2 1 2 2 3 3 4 1))))
+  (loop for first-number = (random 4)
+        for second-number = (+ 5 (random 4))
+        for third-number = (+ 10 (random 4))
+        repeat 10 do
+          (5am:is
+           (equal (data-lens.transducers:transduce
+                   (data-lens:• (data-lens.transducers:catting)
+                                (data-lens.transducers:deduping))
+                   'data-lens.transducers:list-builder
+                   (list (data-lens.transducers:repeating* first-number :count (+ 1 (random 10)))
+                         (data-lens.transducers:repeating* second-number :count (+ 1 (random 5)))
+                         (data-lens.transducers:repeating* third-number :count (+ 1 (random 3)))))
+                  (list first-number second-number third-number)))))
+
+(5am:def-test compressing-runs (:suite :data-lens.transducers)
+  (5am:is (equal '(1 2 1 2 3 4 1)
+                 (data-lens.transducers:transduce (data-lens.transducers:compressing-runs)
+                                                  'data-lens.transducers:list-builder
+                                                  '(1 1 2 1 2 2 3 3 4 1))))
+  (loop for input = '(1) then (cons 1 input)
+        repeat 5 do
+          (5am:is (equal '(1)
+                         (data-lens.transducers:transduce (data-lens.transducers:compressing-runs)
+                                                          'data-lens.transducers:list-builder
+                                                          input))))
+  (loop for input = '(2 1) then (cons 2 input)
+        repeat 5 do
+          (5am:is (equal '(2 1)
+                         (data-lens.transducers:transduce (data-lens.transducers:compressing-runs)
+                                                          'data-lens.transducers:list-builder
+                                                          input))))
+  (loop for input = '(1 2) then (append input '(2))
+        repeat 5 do
+          (5am:is (equal '(1 2)
+                         (data-lens.transducers:transduce (data-lens.transducers:compressing-runs)
+                                                          'data-lens.transducers:list-builder
+                                                          input)))))
+
+(5am:def-test catting (:suite :data-lens.transducers)
+  (5am:is (equal '(1 1 2 1 2 2 3 3 4 1)
+                 (data-lens.transducers:transduce (data-lens.transducers:catting)
+                                                  'data-lens.transducers:list-builder
+                                                  '((1 1) (2 1 2) (2) (3 3) (4 1))))))
+
+(5am:def-test mapcatting (:suite :data-lens.transducers)
+  (5am:is (equal '(1 1 2 1 2 2 3 3 4 1)
+                 (data-lens.transducers:transduce (data-lens.transducers:mapcatting 'list)
+                                                  'data-lens.transducers:list-builder
+                                                  '(1 1 2 1 2 2 3 3 4 1)))))
+
+(5am:def-test splitting (:suite :data-lens.transducers)
+  (5am:is (equal '((2 0) (3 1) (4 2))
+                 (data-lens.transducers:transduce (data-lens.transducers:splitting '1+ '1-)
+                                                  'data-lens.transducers:list-builder
+                                                  '(1 2 3)))))
+
+
 (5am:def-test transducer-composition (:suite :data-lens.transducers)
   (5am:is (equal '(3 5 7)
                  (data-lens.transducers:transduce (data-lens:•
@@ -37,3 +127,23 @@
                                                    (data-lens.transducers:mapping '1+))
                                                   'data-lens.transducers:list-builder
                                                   '(1 2 3)))))
+
+(5am:def-test complicated (:suite :data-lens.transducers)
+  (let ((result (data-lens.transducers:transduce
+                 (data-lens:•
+                  (data-lens.transducers:catting)
+                  (data-lens.transducers:mapping #'parse-integer)
+                  (data-lens.transducers:filtering (complement #'evenp))
+                  (data-lens.transducers:splitting (serapeum:op (* 2 _)) #'identity)
+                  (data-lens.transducers:mapping (data-lens:transform-head #'1+))
+                  (data-lens.transducers:taking 3))
+                 'data-lens.transducers:hash-table-builder
+                 '(("123" "234" "345" "454")
+                   ("568" "490")
+                   ("567" "213")))))
+    (5am:is (equal '((247 . 123)
+                     (691 . 345)
+                     (1135 . 567))
+                   (funcall (data-lens:• (data-lens:sorted '< :key 'car)
+                                         (data-lens:sorted '< :key 'cdr))
+                            (alexandria:hash-table-alist result))))))