From 614d6876c737c54a6679031ca33a1da0c25f0439 Mon Sep 17 00:00:00 2001
From: Jack Firth <jackhfirth@gmail.com>
Date: Tue, 18 Aug 2015 15:34:01 -0700
Subject: [PATCH] Reorganize and add new folders

---
 lens/base/main.rkt                          |   6 +-
 lens/{base => compound}/compose.rkt         |  30 ++---
 lens/{base => compound}/compose.scrbl       |   0
 lens/compound/inverse-function-lens.rkt     |  11 ++
 lens/compound/join-hash.rkt                 |  53 +++++++++
 lens/compound/join-list.rkt                 |  35 ++++++
 lens/compound/join-string.rkt               |  34 ++++++
 lens/compound/join-vector.rkt               |  35 ++++++
 lens/{ => compound}/join.scrbl              |   0
 lens/compound/main.rkt                      |  16 +++
 lens/compound/thrush.rkt                    |  30 +++++
 lens/hash-pick.rkt                          |  30 -----
 lens/{ => hash}/hash.rkt                    |  21 ++--
 lens/{ => hash}/hash.scrbl                  |   0
 lens/hash/main.rkt                          |  10 ++
 lens/hash/pick.rkt                          |  30 +++++
 lens/{hash-pick.scrbl => hash/pick.scrbl}   |   0
 lens/join.rkt                               | 118 --------------------
 lens/list/cadr-etc.rkt                      |   9 +-
 lens/list/list-ref-take-drop.rkt            |   1 +
 lens/list/main.rkt                          |   2 +
 lens/{list.rkt => list/multi.rkt}           |  21 ++--
 lens/{list.scrbl => list/multi.scrbl}       |   0
 lens/main.rkt                               |  20 ++--
 lens/stream.rkt                             |   3 +-
 lens/string.rkt                             |   2 +-
 lens/{struct.rkt => struct/field.rkt}       |  11 +-
 lens/{struct.scrbl => struct/field.scrbl}   |   0
 lens/struct/main.rkt                        |   8 ++
 {unstable/lens => lens/struct}/struct.rkt   |  12 +-
 {unstable/lens => lens/struct}/struct.scrbl |   0
 lens/test-util/test-lens.rkt                |   5 +-
 lens/tests/doc-coverage.rkt                 |   2 +-
 lens/util/list-pair-contract.rkt            |  22 +++-
 lens/util/rest-contract.rkt                 |  11 ++
 lens/vector.rkt                             |  62 ----------
 lens/vector/main.rkt                        |  12 ++
 lens/vector/nested.rkt                      |  27 +++++
 lens/vector/pick.rkt                        |  27 +++++
 lens/vector/ref.rkt                         |  32 ++++++
 lens/{vector.scrbl => vector/ref.scrbl}     |   0
 41 files changed, 463 insertions(+), 285 deletions(-)
 rename lens/{base => compound}/compose.rkt (58%)
 rename lens/{base => compound}/compose.scrbl (100%)
 create mode 100644 lens/compound/inverse-function-lens.rkt
 create mode 100644 lens/compound/join-hash.rkt
 create mode 100644 lens/compound/join-list.rkt
 create mode 100644 lens/compound/join-string.rkt
 create mode 100644 lens/compound/join-vector.rkt
 rename lens/{ => compound}/join.scrbl (100%)
 create mode 100644 lens/compound/main.rkt
 create mode 100644 lens/compound/thrush.rkt
 delete mode 100644 lens/hash-pick.rkt
 rename lens/{ => hash}/hash.rkt (78%)
 rename lens/{ => hash}/hash.scrbl (100%)
 create mode 100644 lens/hash/main.rkt
 create mode 100644 lens/hash/pick.rkt
 rename lens/{hash-pick.scrbl => hash/pick.scrbl} (100%)
 delete mode 100644 lens/join.rkt
 rename lens/{list.rkt => list/multi.rkt} (65%)
 rename lens/{list.scrbl => list/multi.scrbl} (100%)
 rename lens/{struct.rkt => struct/field.rkt} (91%)
 rename lens/{struct.scrbl => struct/field.scrbl} (100%)
 create mode 100644 lens/struct/main.rkt
 rename {unstable/lens => lens/struct}/struct.rkt (94%)
 rename {unstable/lens => lens/struct}/struct.scrbl (100%)
 create mode 100644 lens/util/rest-contract.rkt
 delete mode 100644 lens/vector.rkt
 create mode 100644 lens/vector/main.rkt
 create mode 100644 lens/vector/nested.rkt
 create mode 100644 lens/vector/pick.rkt
 create mode 100644 lens/vector/ref.rkt
 rename lens/{vector.scrbl => vector/ref.scrbl} (100%)

diff --git a/lens/base/main.rkt b/lens/base/main.rkt
index 865fe87..b7a4ab3 100644
--- a/lens/base/main.rkt
+++ b/lens/base/main.rkt
@@ -3,13 +3,11 @@
 (require "base.rkt"
          "view-set.rkt"
          "transform.rkt"
-         "identity.rkt"
-         "compose.rkt")
+         "identity.rkt")
 
 (provide
  (all-from-out
   "base.rkt"
   "view-set.rkt"
   "transform.rkt"
-  "identity.rkt"
-  "compose.rkt"))
+  "identity.rkt"))
diff --git a/lens/base/compose.rkt b/lens/compound/compose.rkt
similarity index 58%
rename from lens/base/compose.rkt
rename to lens/compound/compose.rkt
index 4f43f09..b962c38 100644
--- a/lens/base/compose.rkt
+++ b/lens/compound/compose.rkt
@@ -1,16 +1,15 @@
-#lang racket
+#lang racket/base
 
-(require fancy-app
-         "base.rkt"
-         "view-set.rkt"
-         "identity.rkt")
+(require racket/contract
+         racket/list
+         fancy-app
+         "../base/main.rkt")
 
 (module+ test
   (require rackunit))
 
 (provide
- (contract-out [lens-compose (->* () () #:rest (listof lens?) lens?)]
-               [lens-thrush (->* () () #:rest (listof lens?) lens?)]))
+ (contract-out [lens-compose (->* () () #:rest (listof lens?) lens?)]))
 
 
 (define (lens-compose2 sub-lens super-lens)
@@ -34,18 +33,7 @@
   (define (set-second l v)
     (list* (first l) v (rest (rest l))))
   (define second-lens (make-lens second set-second))
-  (define first-of-second-lens (lens-compose first-lens second-lens))
   (define test-alist '((a 1) (b 2) (c 3)))
-  (check-eq? (lens-view first-of-second-lens test-alist) 'b)
-  (check-equal? (lens-set first-of-second-lens test-alist 'B)
-                '((a 1) (B 2) (c 3))))
-
-
-(define (lens-thrush . args)
-  (apply lens-compose (reverse args)))
-
-(module+ test
-  (define first-of-second-lens* (lens-thrush second-lens first-lens))
-  (let-lens [val ctxt] first-of-second-lens* test-alist
-    (check-equal? val 'b)
-    (check-equal? (ctxt 'B) '((a 1) (B 2) (c 3)))))
+  (define first-of-second-lens (lens-compose first-lens second-lens))
+  (check-equal? (lens-view first-of-second-lens test-alist) 'b)
+  (check-equal? (lens-set first-of-second-lens test-alist 'B) '((a 1) (B 2) (c 3))))
diff --git a/lens/base/compose.scrbl b/lens/compound/compose.scrbl
similarity index 100%
rename from lens/base/compose.scrbl
rename to lens/compound/compose.scrbl
diff --git a/lens/compound/inverse-function-lens.rkt b/lens/compound/inverse-function-lens.rkt
new file mode 100644
index 0000000..028ece1
--- /dev/null
+++ b/lens/compound/inverse-function-lens.rkt
@@ -0,0 +1,11 @@
+#lang racket/base
+
+(require "../base/main.rkt")
+
+(provide inverse-function-lens)
+
+
+(define (inverse-function-lens f f-inv)
+  (make-lens
+   (λ (tgt) (f tgt))
+   (λ (tgt v) (f-inv v))))
diff --git a/lens/compound/join-hash.rkt b/lens/compound/join-hash.rkt
new file mode 100644
index 0000000..a393e69
--- /dev/null
+++ b/lens/compound/join-hash.rkt
@@ -0,0 +1,53 @@
+#lang racket/base
+
+(require racket/contract
+         racket/match
+         unstable/sequence
+         fancy-app
+         "../base/main.rkt"
+         "../util/immutable.rkt"
+         "../util/list-pair-contract.rkt"
+         "join-list.rkt")
+
+(module+ test
+  (require rackunit
+           "../list/list-ref-take-drop.rkt"))
+
+(provide
+ (contract-out
+  [lens-join/hash (->* () #:rest (listof2 any/c lens?) (lens/c any/c immutable-hash?))]))
+
+
+(define (value-list->hash keys vs)
+  (make-immutable-hash (map cons keys vs)))
+
+(define (split-slice n vs)
+  (define grouped
+    (for/list ([group (in-slice n vs)])
+      group))
+  (define (get-ith i)
+    (map (list-ref _ i) grouped))
+  (build-list n get-ith))
+
+(module+ test
+  (check-equal? (split-slice 3 '(a 1 FOO b 2 BAR c 3 BAZ))
+                '((a b c) (1 2 3) (FOO BAR BAZ))))
+
+
+(define (lens-join/hash . keys/lenses)
+  (match-define (list keys lenses) (split-slice 2 keys/lenses))
+  (define list-lens (apply lens-join/list lenses))
+  (define (get target)
+    (value-list->hash keys (lens-view list-lens target)))
+  (define (set target new-view-hash)
+    (lens-set list-lens target (map (hash-ref new-view-hash _) keys)))
+  (make-lens get set))
+
+(module+ test
+  (define a-b-lens (lens-join/hash 'b third-lens
+                                   'a first-lens))
+  (check-equal? (lens-view a-b-lens '(1 2 3))
+                (hash 'a 1 'b 3))
+  (check-equal? (lens-set a-b-lens '(1 2 3) (hash 'a 100 'b 200))
+                '(100 2 200)))
+
diff --git a/lens/compound/join-list.rkt b/lens/compound/join-list.rkt
new file mode 100644
index 0000000..08f9ebc
--- /dev/null
+++ b/lens/compound/join-list.rkt
@@ -0,0 +1,35 @@
+#lang racket/base
+
+(require racket/list
+         racket/contract
+         "../base/main.rkt")
+
+(module+ test
+  (require rackunit
+           "../list/list-ref-take-drop.rkt"))
+
+(provide
+ (contract-out
+  [lens-join/list (->* () #:rest (listof lens?) (lens/c any/c list?))]))
+
+
+(define (zip xs ys)
+  (append-map list xs ys))
+
+(define (lens-join/list . lenses)
+  (define (get target)
+    (apply lens-view/list target lenses))
+  (define (set target new-views)
+    (apply lens-set/list target (zip lenses new-views)))
+  (make-lens get set))
+
+
+(module+ test
+  (define first-third-fifth-lens
+    (lens-join/list first-lens
+                    third-lens
+                    fifth-lens))
+  (check-equal? (lens-view first-third-fifth-lens '(a b c d e f))
+                '(a c e))
+  (check-equal? (lens-set first-third-fifth-lens '(a b c d e f) '(1 2 3))
+                '(1 b 2 d 3 f)))
diff --git a/lens/compound/join-string.rkt b/lens/compound/join-string.rkt
new file mode 100644
index 0000000..2081ff3
--- /dev/null
+++ b/lens/compound/join-string.rkt
@@ -0,0 +1,34 @@
+#lang racket/base
+
+(require racket/contract
+         "../base/main.rkt"
+         "../util/immutable.rkt"
+         "compose.rkt"
+         "inverse-function-lens.rkt"
+         "join-list.rkt")
+
+(module+ test
+  (require rackunit
+           "../list/list-ref-take-drop.rkt"))
+
+(provide
+ (contract-out
+  [lens-join/string (->* () #:rest (listof lens?) (lens/c any/c immutable-string?))]))
+
+
+(define (lens-join/string . lenses)
+  (lens-compose list->string-lens (apply lens-join/list lenses)))
+
+(define list->string-lens
+  (inverse-function-lens list->immutable-string string->list))
+
+(module+ test
+  (define string-first-third-fifth-lens
+    (lens-join/string first-lens
+                      third-lens
+                      fifth-lens))
+  (check-equal? (lens-view string-first-third-fifth-lens '(#\a #\b #\c #\d #\e #\f))
+                "ace")
+  (check-pred immutable? (lens-view string-first-third-fifth-lens '(#\a #\b #\c #\d #\e #\f)))
+  (check-equal? (lens-set string-first-third-fifth-lens '(#\a #\b #\c #\d #\e #\f) "ACE")
+                '(#\A #\b #\C #\d #\E #\f)))
diff --git a/lens/compound/join-vector.rkt b/lens/compound/join-vector.rkt
new file mode 100644
index 0000000..01bf200
--- /dev/null
+++ b/lens/compound/join-vector.rkt
@@ -0,0 +1,35 @@
+#lang racket/base
+
+(require racket/contract
+         "../base/main.rkt"
+         "../util/immutable.rkt"
+         "compose.rkt"
+         "inverse-function-lens.rkt"
+         "join-list.rkt")
+
+(module+ test
+  (require rackunit
+           "../list/list-ref-take-drop.rkt"))
+
+(provide
+ (contract-out
+  [lens-join/vector (->* () #:rest (listof lens?) (lens/c any/c immutable-vector?))]))
+
+
+(define (lens-join/vector . lenses)
+  (lens-compose list->vector-lens (apply lens-join/list lenses)))
+
+(define list->vector-lens
+  (inverse-function-lens list->immutable-vector vector->list))
+
+(module+ test
+  (define vector-first-third-fifth-lens
+    (lens-join/vector first-lens
+                      third-lens
+                      fifth-lens))
+  (check-equal? (lens-view vector-first-third-fifth-lens '(a b c d e f))
+                #(a c e))
+  (check-pred immutable? (lens-view vector-first-third-fifth-lens '(a b c d e f)))
+  (check-equal? (lens-set vector-first-third-fifth-lens '(a b c d e f) #(1 2 3))
+                '(1 b 2 d 3 f)))
+
diff --git a/lens/join.scrbl b/lens/compound/join.scrbl
similarity index 100%
rename from lens/join.scrbl
rename to lens/compound/join.scrbl
diff --git a/lens/compound/main.rkt b/lens/compound/main.rkt
new file mode 100644
index 0000000..b82bc06
--- /dev/null
+++ b/lens/compound/main.rkt
@@ -0,0 +1,16 @@
+#lang racket/base
+
+(require "compose.rkt"
+         "join-hash.rkt"
+         "join-list.rkt"
+         "join-string.rkt"
+         "join-vector.rkt"
+         "thrush.rkt")
+
+(provide (all-from-out
+          "compose.rkt"
+          "join-hash.rkt"
+          "join-list.rkt"
+          "join-string.rkt"
+          "join-vector.rkt"
+          "thrush.rkt"))
diff --git a/lens/compound/thrush.rkt b/lens/compound/thrush.rkt
new file mode 100644
index 0000000..3a2d176
--- /dev/null
+++ b/lens/compound/thrush.rkt
@@ -0,0 +1,30 @@
+#lang racket/base
+
+(require racket/contract
+         racket/list
+         fancy-app
+         "../base/main.rkt"
+         "compose.rkt")
+
+(module+ test
+  (require rackunit
+           "../list/list-ref-take-drop.rkt"))
+
+(provide
+ (contract-out [lens-thrush (->* () () #:rest (listof lens?) lens?)]))
+
+
+(define (lens-thrush . args)
+  (apply lens-compose (reverse args)))
+
+(module+ test
+  (define (set-first l v)
+    (list* v (rest l)))
+  (define first-lens (make-lens first set-first))
+  (define (set-second l v)
+    (list* (first l) v (rest (rest l))))
+  (define second-lens (make-lens second set-second))
+  (define test-alist '((a 1) (b 2) (c 3)))
+  (define first-of-second-lens (lens-thrush second-lens first-lens))
+  (check-equal? (lens-view first-of-second-lens test-alist) 'b)
+  (check-equal? (lens-set first-of-second-lens test-alist 'B) '((a 1) (B 2) (c 3))))
diff --git a/lens/hash-pick.rkt b/lens/hash-pick.rkt
deleted file mode 100644
index 820cd0c..0000000
--- a/lens/hash-pick.rkt
+++ /dev/null
@@ -1,30 +0,0 @@
-#lang racket/base
-
-(require racket/contract/base)
-(provide (contract-out
-          [hash-pick-lens
-           (->* [] #:rest list? (lens/c immutable-hash? immutable-hash?))]
-          ))
-
-(require racket/list
-         "base/main.rkt"
-         "util/immutable.rkt"
-         "hash.rkt"
-         "join.rkt")
-
-(module+ test
-  (require rackunit))
-
-(define (hash-pick-lens . ks)
-  (apply lens-join/hash
-         (append-map
-          (λ (k)
-            (list k (hash-ref-lens k)))
-          ks)))
-
-(module+ test
-  (check-equal? (lens-view (hash-pick-lens 'a 'c) (hash 'a 1 'b 2 'c 3))
-                (hash 'a 1 'c 3))
-  (check-equal? (lens-set (hash-pick-lens 'a 'c) (hash 'a 1 'b 2 'c 3) (hash 'a 4 'c 5))
-                (hash 'a 4 'b 2 'c 5))
-  )
diff --git a/lens/hash.rkt b/lens/hash/hash.rkt
similarity index 78%
rename from lens/hash.rkt
rename to lens/hash/hash.rkt
index 7aff9e6..9f26690 100644
--- a/lens/hash.rkt
+++ b/lens/hash/hash.rkt
@@ -1,16 +1,19 @@
-#lang racket
+#lang racket/base
+
+(require racket/contract
+         fancy-app
+         "../base/main.rkt"
+         "../compound/main.rkt"
+         "../util/immutable.rkt"
+         "../util/rest-contract.rkt")
+
+(module+ test
+  (require rackunit))
 
 (provide
  (contract-out
   [hash-ref-lens (-> any/c (lens/c immutable-hash? any/c))]
-  [hash-ref-nested-lens (->* () #:rest list? (lens/c immutable-hash? any/c))]))
-
-(require fancy-app
-         "base/main.rkt"
-         "util/immutable.rkt")
-
-(module+ test
-  (require rackunit))
+  [hash-ref-nested-lens (rest-> any/c (lens/c immutable-hash? any/c))]))
 
 
 (define (hash-ref-lens key)
diff --git a/lens/hash.scrbl b/lens/hash/hash.scrbl
similarity index 100%
rename from lens/hash.scrbl
rename to lens/hash/hash.scrbl
diff --git a/lens/hash/main.rkt b/lens/hash/main.rkt
new file mode 100644
index 0000000..9194492
--- /dev/null
+++ b/lens/hash/main.rkt
@@ -0,0 +1,10 @@
+#lang racket/base
+
+
+(require "hash.rkt"
+         "pick.rkt")
+
+
+(provide
+ (all-from-out "hash.rkt"
+               "pick.rkt"))
diff --git a/lens/hash/pick.rkt b/lens/hash/pick.rkt
new file mode 100644
index 0000000..f0cd441
--- /dev/null
+++ b/lens/hash/pick.rkt
@@ -0,0 +1,30 @@
+#lang racket/base
+
+(require racket/contract
+         racket/list
+         "../base/main.rkt"
+         "../compound/join-hash.rkt"
+         "../util/immutable.rkt"
+         "../util/rest-contract.rkt"
+         "hash.rkt")
+
+(module+ test
+  (require rackunit))
+
+(provide
+ (contract-out
+  [hash-pick-lens (rest-> any/c (lens/c immutable-hash? immutable-hash?))]))
+
+
+(define (hash-ref-lens-and-key k)
+  (list k (hash-ref-lens k)))
+
+(define (hash-pick-lens . ks)
+  (apply lens-join/hash
+         (append-map hash-ref-lens-and-key ks)))
+
+(module+ test
+  (check-equal? (lens-view (hash-pick-lens 'a 'c) (hash 'a 1 'b 2 'c 3))
+                (hash 'a 1 'c 3))
+  (check-equal? (lens-set (hash-pick-lens 'a 'c) (hash 'a 1 'b 2 'c 3) (hash 'a 4 'c 5))
+                (hash 'a 4 'b 2 'c 5)))
diff --git a/lens/hash-pick.scrbl b/lens/hash/pick.scrbl
similarity index 100%
rename from lens/hash-pick.scrbl
rename to lens/hash/pick.scrbl
diff --git a/lens/join.rkt b/lens/join.rkt
deleted file mode 100644
index 906c090..0000000
--- a/lens/join.rkt
+++ /dev/null
@@ -1,118 +0,0 @@
-#lang racket
-
-(require fancy-app
-         "base/main.rkt"
-         "list/main.rkt"
-         "util/list-pair-contract.rkt"
-         "util/immutable.rkt"
-         unstable/sequence)
-
-(module+ test
-  (require rackunit))
-
-(provide
- (contract-out
-  [lens-join/list (->* () #:rest (listof lens?) (lens/c any/c list?))]
-  [lens-join/hash (->* () #:rest (listof2 any/c lens?) (lens/c any/c immutable-hash?))]
-  [lens-join/vector (->* () #:rest (listof lens?) (lens/c any/c immutable-vector?))]
-  [lens-join/string (->* () #:rest (listof lens?) (lens/c any/c immutable-string?))]
-  ))
-
-
-(define (zip xs ys)
-  (append-map list xs ys))
-
-(define (lens-join/list . lenses)
-  (define (get target)
-    (apply lens-view/list target lenses))
-  (define (set target new-views)
-    (apply lens-set/list target (zip lenses new-views)))
-  (make-lens get set))
-
-
-(module+ test
-  (define first-third-fifth-lens
-    (lens-join/list first-lens
-                    third-lens
-                    fifth-lens))
-  (check-equal? (lens-view first-third-fifth-lens '(a b c d e f))
-                '(a c e))
-  (check-equal? (lens-set first-third-fifth-lens '(a b c d e f) '(1 2 3))
-                '(1 b 2 d 3 f)))
-(define first-first-lens
-  (lens-join/list first-lens
-                  first-lens))
-
-
-(define (value-list->hash keys vs)
-  (make-immutable-hash (map cons keys vs)))
-
-(define (split-slice n vs)
-  (define grouped
-    (for/list ([group (in-slice n vs)])
-      group))
-  (define (get-ith i)
-    (map (list-ref _ i) grouped))
-  (build-list n get-ith))
-
-(module+ test
-  (check-equal? (split-slice 3 '(a 1 FOO b 2 BAR c 3 BAZ))
-                '((a b c) (1 2 3) (FOO BAR BAZ))))
-
-
-(define (lens-join/hash . keys/lenses)
-  (match-define (list keys lenses) (split-slice 2 keys/lenses))
-  (define list-lens (apply lens-join/list lenses))
-  (define (get target)
-    (value-list->hash keys (lens-view list-lens target)))
-  (define (set target new-view-hash)
-    (lens-set list-lens target (map (hash-ref new-view-hash _) keys)))
-  (make-lens get set))
-
-(module+ test
-  (define a-b-lens (lens-join/hash 'b third-lens
-                                   'a first-lens))
-  (check-equal? (lens-view a-b-lens '(1 2 3))
-                (hash 'a 1 'b 3))
-  (check-equal? (lens-set a-b-lens '(1 2 3) (hash 'a 100 'b 200))
-                '(100 2 200)))
-
-
-(define (lens-join/vector . lenses)
-  (lens-compose list->vector-lens (apply lens-join/list lenses)))
-
-(define (inverse-function-lens f f-inv)
-  (make-lens
-   (λ (tgt) (f tgt))
-   (λ (tgt v) (f-inv v))))
-
-(define list->vector-lens
-  (inverse-function-lens list->immutable-vector vector->list))
-
-(module+ test
-  (define vector-first-third-fifth-lens
-    (lens-join/vector first-lens
-                      third-lens
-                      fifth-lens))
-  (check-equal? (lens-view vector-first-third-fifth-lens '(a b c d e f))
-                #(a c e))
-  (check-pred immutable? (lens-view vector-first-third-fifth-lens '(a b c d e f)))
-  (check-equal? (lens-set vector-first-third-fifth-lens '(a b c d e f) #(1 2 3))
-                '(1 b 2 d 3 f)))
-
-(define (lens-join/string . lenses)
-  (lens-compose list->string-lens (apply lens-join/list lenses)))
-
-(define list->string-lens
-  (inverse-function-lens list->immutable-string string->list))
-
-(module+ test
-  (define string-first-third-fifth-lens
-    (lens-join/string first-lens
-                      third-lens
-                      fifth-lens))
-  (check-equal? (lens-view string-first-third-fifth-lens '(#\a #\b #\c #\d #\e #\f))
-                "ace")
-  (check-pred immutable? (lens-view string-first-third-fifth-lens '(#\a #\b #\c #\d #\e #\f)))
-  (check-equal? (lens-set string-first-third-fifth-lens '(#\a #\b #\c #\d #\e #\f) "ACE")
-                '(#\A #\b #\C #\d #\E #\f)))
diff --git a/lens/list/cadr-etc.rkt b/lens/list/cadr-etc.rkt
index 76b5b3f..04a8d44 100644
--- a/lens/list/cadr-etc.rkt
+++ b/lens/list/cadr-etc.rkt
@@ -1,9 +1,12 @@
-#lang racket
+#lang racket/base
 
-(require syntax/parse/define
+(require racket/contract
+         syntax/parse/define
          "../base/main.rkt"
+         "../compound/main.rkt"
          "car-cdr.rkt"
-         (for-syntax racket/syntax))
+         (for-syntax racket/base
+                     racket/syntax))
 
 (module+ test
   (require rackunit))
diff --git a/lens/list/list-ref-take-drop.rkt b/lens/list/list-ref-take-drop.rkt
index b01500e..73f66eb 100644
--- a/lens/list/list-ref-take-drop.rkt
+++ b/lens/list/list-ref-take-drop.rkt
@@ -26,6 +26,7 @@
          fancy-app
          "../util/improper-list-length.rkt"
          "../base/main.rkt"
+         "../compound/compose.rkt"
          "car-cdr.rkt")
 
 (module+ test
diff --git a/lens/list/main.rkt b/lens/list/main.rkt
index 37bacce..a7fc4fc 100644
--- a/lens/list/main.rkt
+++ b/lens/list/main.rkt
@@ -3,10 +3,12 @@
 (require "car-cdr.rkt"
          "list-ref-take-drop.rkt"
          "cadr-etc.rkt"
+         "multi.rkt"
          "assoc.rkt")
 
 (provide (all-from-out
           "car-cdr.rkt"
           "list-ref-take-drop.rkt"
           "cadr-etc.rkt"
+          "multi.rkt"
           "assoc.rkt"))
diff --git a/lens/list.rkt b/lens/list/multi.rkt
similarity index 65%
rename from lens/list.rkt
rename to lens/list/multi.rkt
index ef11993..980714a 100644
--- a/lens/list.rkt
+++ b/lens/list/multi.rkt
@@ -1,21 +1,18 @@
-#lang racket
+#lang racket/base
 
-(require "base/main.rkt"
-         "list/main.rkt"
-         "join.rkt")
+(require racket/contract
+         "../base/main.rkt"
+         "../compound/main.rkt"
+         "../util/rest-contract.rkt"
+         "list-ref-take-drop.rkt")
 
 (module+ test
   (require rackunit))
 
 (provide
-  (contract-out
-    [list-ref-nested-lens
-     (->* () #:rest (listof exact-nonnegative-integer?)
-          lens?)]
-    [list-refs-lens
-     (->* () #:rest (listof exact-nonnegative-integer?)
-          (lens/c list? list?))]
-    ))
+ (contract-out
+  [list-ref-nested-lens (rest-> exact-nonnegative-integer? lens?)]
+  [list-refs-lens (rest-> exact-nonnegative-integer? (lens/c list? list?))]))
 
 
 (define (list-ref-nested-lens . indices)
diff --git a/lens/list.scrbl b/lens/list/multi.scrbl
similarity index 100%
rename from lens/list.scrbl
rename to lens/list/multi.scrbl
diff --git a/lens/main.rkt b/lens/main.rkt
index 2820ee4..92fa4f5 100644
--- a/lens/main.rkt
+++ b/lens/main.rkt
@@ -1,22 +1,28 @@
-#lang racket
+#lang racket/base
 
 (require
   "base/main.rkt"
+  "compound/main.rkt"
+  "hash/main.rkt"
   "list/main.rkt"
-  "struct.rkt"
+  "struct/main.rkt"
   "dict.rkt"
-  "hash.rkt"
-  "stream.rkt")
+  "stream.rkt"
+  "string.rkt"
+  "vector/main.rkt")
 
 (provide
  (except-out
   (all-from-out
    "base/main.rkt"
+   "compound/main.rkt"
+   "hash/main.rkt"
    "list/main.rkt"
-   "struct.rkt"
+   "struct/main.rkt"
+   "vector/main.rkt"
    "dict.rkt"
-   "hash.rkt"
-   "stream.rkt")
+   "stream.rkt"
+   "string.rkt")
   focus-lens
   drop-lens
   take-lens
diff --git a/lens/stream.rkt b/lens/stream.rkt
index 6f412a8..882e7c4 100644
--- a/lens/stream.rkt
+++ b/lens/stream.rkt
@@ -6,7 +6,8 @@
 
 (require racket/stream
          fancy-app
-         "base/main.rkt")
+         "base/main.rkt"
+         "compound/main.rkt")
 
 (module+ test
   (require rackunit "test-util/test-lens.rkt"))
diff --git a/lens/string.rkt b/lens/string.rkt
index 3fbe370..c0be661 100644
--- a/lens/string.rkt
+++ b/lens/string.rkt
@@ -13,7 +13,7 @@
 (require fancy-app
          "base/main.rkt"
          "util/immutable.rkt"
-         "join.rkt")
+         "compound/main.rkt")
 
 (module+ test
   (require rackunit))
diff --git a/lens/struct.rkt b/lens/struct/field.rkt
similarity index 91%
rename from lens/struct.rkt
rename to lens/struct/field.rkt
index f0ec22e..ec4285f 100644
--- a/lens/struct.rkt
+++ b/lens/struct/field.rkt
@@ -1,18 +1,19 @@
 #lang racket/base
 
-(provide struct-lens)
-
 (require racket/local
          syntax/parse/define
          alexis/util/struct
-         "base/main.rkt"
+         "../base/main.rkt"
          (for-syntax racket/base
                      syntax/parse
-                     racket/syntax
-                     ))
+                     racket/syntax))
+
 (module+ test
   (require rackunit fancy-app))
 
+(provide struct-lens)
+
+
 (define-simple-macro (struct-lens s:id fld:id)
   #:with s-fld      (format-id #'s "~a-~a" #'s #'fld #:source #'fld)
   #:with s-fld-set  (format-id #'s "~a-~a-set" #'s #'fld #:source #'fld)
diff --git a/lens/struct.scrbl b/lens/struct/field.scrbl
similarity index 100%
rename from lens/struct.scrbl
rename to lens/struct/field.scrbl
diff --git a/lens/struct/main.rkt b/lens/struct/main.rkt
new file mode 100644
index 0000000..3912407
--- /dev/null
+++ b/lens/struct/main.rkt
@@ -0,0 +1,8 @@
+#lang racket/base
+
+(require "field.rkt"
+         "struct.rkt")
+
+(provide
+ (all-from-out "field.rkt"
+               "struct.rkt"))
diff --git a/unstable/lens/struct.rkt b/lens/struct/struct.rkt
similarity index 94%
rename from unstable/lens/struct.rkt
rename to lens/struct/struct.rkt
index 93e00f4..ee9d694 100644
--- a/unstable/lens/struct.rkt
+++ b/lens/struct/struct.rkt
@@ -1,8 +1,5 @@
 #lang racket/base
 
-(provide define-struct-lenses
-         struct/lens)
-
 (require syntax/parse/define
          lens/base/main
          alexis/util/struct
@@ -10,12 +7,15 @@
          (for-syntax racket/base
                      syntax/parse
                      racket/syntax
-                     racket/struct-info
-                     ))
+                     racket/struct-info))
+
 (module+ test
   (require rackunit
            fancy-app
-           lens/test-util/test-lens))
+           "../test-util/test-lens.rkt"))
+
+(provide define-struct-lenses
+         struct/lens)
 
 
 (define-for-syntax (get-struct-field-ids struct-info failure-context)
diff --git a/unstable/lens/struct.scrbl b/lens/struct/struct.scrbl
similarity index 100%
rename from unstable/lens/struct.scrbl
rename to lens/struct/struct.scrbl
diff --git a/lens/test-util/test-lens.rkt b/lens/test-util/test-lens.rkt
index def9054..42608b0 100644
--- a/lens/test-util/test-lens.rkt
+++ b/lens/test-util/test-lens.rkt
@@ -1,6 +1,7 @@
-#lang racket
+#lang racket/base
 
-(require rackunit
+(require racket/contract
+         rackunit
          fancy-app
          "../base/base.rkt"
          "../base/view-set.rkt")
diff --git a/lens/tests/doc-coverage.rkt b/lens/tests/doc-coverage.rkt
index b7d1f0b..28aeb05 100644
--- a/lens/tests/doc-coverage.rkt
+++ b/lens/tests/doc-coverage.rkt
@@ -1,4 +1,4 @@
-#lang racket
+#lang racket/base
 
 (require doc-coverage
          lens)
diff --git a/lens/util/list-pair-contract.rkt b/lens/util/list-pair-contract.rkt
index 411a3e3..649bc88 100644
--- a/lens/util/list-pair-contract.rkt
+++ b/lens/util/list-pair-contract.rkt
@@ -1,10 +1,26 @@
-#lang racket
+#lang racket/base
+
+(require racket/contract
+         racket/list
+         racket/match)
 
 (provide
  (contract-out [listof2 (-> contract? contract? contract?)]))
 
 
-(define (listof2 first-val/c second-val/c)
+(define (list*/c . contracts)
+  (match contracts
+    [(list end-contract)
+     end-contract]
+    [(list* head-contract rest-contracts)
+     (cons/c head-contract
+             (apply list*/c rest-contracts))]))
+
+(define (repeating-list/c . contracts)
   (define c
-    (or/c empty? (cons/c first-val/c (cons/c second-val/c (recursive-contract c)))))
+    (or/c empty?
+          (apply list*/c (append contracts (list (recursive-contract c))))))
   c)
+
+(define (listof2 first-val/c second-val/c)
+  (repeating-list/c first-val/c second-val/c))
diff --git a/lens/util/rest-contract.rkt b/lens/util/rest-contract.rkt
new file mode 100644
index 0000000..2d7985e
--- /dev/null
+++ b/lens/util/rest-contract.rkt
@@ -0,0 +1,11 @@
+#lang racket/base
+
+(require racket/contract)
+
+(provide
+ (contract-out
+  [rest-> (-> contract? contract? contract?)]))
+
+
+(define (rest-> arg-contract result-contract)
+  (->* () #:rest (listof arg-contract) result-contract))
diff --git a/lens/vector.rkt b/lens/vector.rkt
deleted file mode 100644
index 2fb8b8f..0000000
--- a/lens/vector.rkt
+++ /dev/null
@@ -1,62 +0,0 @@
-#lang racket/base
-
-(require racket/contract/base)
-(provide (contract-out
-          [vector-ref-lens
-           (-> exact-nonnegative-integer?
-               (lens/c immutable-vector? any/c))]
-          [vector-ref-nested-lens
-           (->* [] #:rest (listof exact-nonnegative-integer?)
-                (lens/c immutable-vector? any/c))]
-          [vector-pick-lens
-           (->* [] #:rest (listof exact-nonnegative-integer?)
-                (lens/c immutable-vector? immutable-vector?))]
-          ))
-
-(require fancy-app
-         "base/main.rkt"
-         "list/main.rkt"
-         "util/immutable.rkt"
-         "join.rkt")
-
-(module+ test
-  (require rackunit))
-
-
-(define (vector-ref-lens i)
-  (make-lens
-   (vector-ref _ i)
-   (vector-set _ i _)))
-
-(define (vector-set v i x)
-  (build-immutable-vector
-   (vector-length v)
-   (λ (j)
-     (if (= i j)
-         x
-         (vector-ref v j)))))
-
-(module+ test
-  (check-equal? (lens-view (vector-ref-lens 0) #(a b c)) 'a)
-  (check-equal? (lens-set (vector-ref-lens 2) #(a b c) "C") #(a b "C")))
-
-
-(define (vector-ref-nested-lens . is)
-  (apply lens-thrush (map vector-ref-lens is)))
-
-(module+ test
-  (check-equal? (lens-transform (vector-ref-nested-lens 2 1)
-                                #(a #(b c) #(d e f))
-                                symbol->string)
-                #(a #(b c) #(d "e" f))))
-
-
-(define (vector-pick-lens . is)
-  (apply lens-join/vector (map vector-ref-lens is)))
-
-(module+ test
-  (define 1-5-6-lens (vector-pick-lens 1 5 6))
-  (check-equal? (lens-view 1-5-6-lens #(a b c d e f g))
-                #(b f g))
-  (check-equal? (lens-set 1-5-6-lens #(a b c d e f g) #(1 2 3))
-                #(a 1 c d e 2 3)))
diff --git a/lens/vector/main.rkt b/lens/vector/main.rkt
new file mode 100644
index 0000000..24d3654
--- /dev/null
+++ b/lens/vector/main.rkt
@@ -0,0 +1,12 @@
+#lang racket/base
+
+
+(require "nested.rkt"
+         "pick.rkt"
+         "ref.rkt")
+
+
+(provide
+ (all-from-out "nested.rkt"
+               "pick.rkt"
+               "ref.rkt"))
diff --git a/lens/vector/nested.rkt b/lens/vector/nested.rkt
new file mode 100644
index 0000000..1a610e8
--- /dev/null
+++ b/lens/vector/nested.rkt
@@ -0,0 +1,27 @@
+#lang racket/base
+
+(require racket/contract
+         "../base/main.rkt"
+         "../compound/main.rkt"
+         "../util/immutable.rkt"
+         "../util/rest-contract.rkt"
+         "ref.rkt")
+
+(module+ test
+  (require rackunit))
+
+(provide
+ (contract-out
+  [vector-ref-nested-lens (rest-> exact-nonnegative-integer?
+                                  (lens/c immutable-vector? any/c))]))
+
+
+(define (vector-ref-nested-lens . is)
+  (apply lens-thrush (map vector-ref-lens is)))
+
+(module+ test
+  (check-equal? (lens-transform (vector-ref-nested-lens 2 1)
+                                #(a #(b c) #(d e f))
+                                symbol->string)
+                #(a #(b c) #(d "e" f))))
+
diff --git a/lens/vector/pick.rkt b/lens/vector/pick.rkt
new file mode 100644
index 0000000..85252dd
--- /dev/null
+++ b/lens/vector/pick.rkt
@@ -0,0 +1,27 @@
+#lang racket/base
+
+(require racket/contract
+         "../base/main.rkt"
+         "../compound/main.rkt"
+         "../util/immutable.rkt"
+         "../util/rest-contract.rkt"
+         "ref.rkt")
+
+(module+ test
+  (require rackunit))
+
+(provide
+ (contract-out
+  [vector-pick-lens (rest-> exact-nonnegative-integer?
+                            (lens/c immutable-vector? immutable-vector?))]))
+
+
+(define (vector-pick-lens . is)
+  (apply lens-join/vector (map vector-ref-lens is)))
+
+(module+ test
+  (define 1-5-6-lens (vector-pick-lens 1 5 6))
+  (check-equal? (lens-view 1-5-6-lens #(a b c d e f g))
+                #(b f g))
+  (check-equal? (lens-set 1-5-6-lens #(a b c d e f g) #(1 2 3))
+                #(a 1 c d e 2 3)))
diff --git a/lens/vector/ref.rkt b/lens/vector/ref.rkt
new file mode 100644
index 0000000..d2dbf7e
--- /dev/null
+++ b/lens/vector/ref.rkt
@@ -0,0 +1,32 @@
+#lang racket/base
+
+(require racket/contract
+         fancy-app
+         "../base/main.rkt"
+         "../util/immutable.rkt")
+
+(module+ test
+  (require rackunit))
+
+(provide
+ (contract-out
+  [vector-ref-lens (-> exact-nonnegative-integer?
+                       (lens/c immutable-vector? any/c))]))
+
+
+(define (vector-ref-lens i)
+  (make-lens
+   (vector-ref _ i)
+   (vector-set _ i _)))
+
+(define (vector-set v i x)
+  (build-immutable-vector
+   (vector-length v)
+   (λ (j)
+     (if (= i j)
+         x
+         (vector-ref v j)))))
+
+(module+ test
+  (check-equal? (lens-view (vector-ref-lens 0) #(a b c)) 'a)
+  (check-equal? (lens-set (vector-ref-lens 2) #(a b c) "C") #(a b "C")))
diff --git a/lens/vector.scrbl b/lens/vector/ref.scrbl
similarity index 100%
rename from lens/vector.scrbl
rename to lens/vector/ref.scrbl