Merge pull request #57 from lexi-lambda/document-lens-thrush

Add documentation for and expose lens-thrush

lenses/core/compose.scrbl

@@ -21,6 +21,16 @@
     (lens-set first-of-second-lens '((1 a) (2 b) (3 c)) 200)
 ]}
 
+@defproc[(lens-thrush [lens lens?] ...) lens?]{
+  Like @racket[lens-compose], but each @racket[lens] is combined in the
+  opposite order. That is, the first @racket[lens] is the first
+  @racket[lens] that the compound lens’s target is viewed through.
+  @lenses-examples[
+    (define first-of-second-lens (lens-thrush second-lens first-lens))
+    (lens-view first-of-second-lens '((1 a) (2 b) (3 c)))
+    (lens-set first-of-second-lens '((1 a) (2 b) (3 c)) 200)
+]}
+
 @defthing[identity-lens lens?]{
   The identity lens. Performs no destructuring at all - it's view is
   the target itself. For all lenses, both

lenses/main.rkt

@@ -16,7 +16,6 @@
   apply-lens
   drop-lens
   lens-set*
-  lens-thrush
   lens-transform*
   lens-view*
   list-ref-lens