-
Notifications
You must be signed in to change notification settings - Fork 8
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
Showing
4 changed files
with
97 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,42 @@ | ||
#lang racket/base | ||
|
||
(provide lens-view-> | ||
lens-set-> | ||
lens-transform-> | ||
lens-view/thrush | ||
lens-set/thrush | ||
lens-transform/thrush | ||
) | ||
|
||
(require lens/base/main) | ||
(module+ test | ||
(require rackunit racket/list fancy-app)) | ||
|
||
(define (lens-view-> target . lenses) | ||
(for/fold ([target target]) ([lens (in-list lenses)]) | ||
(lens-view lens target))) | ||
|
||
(define (lens-set-> target #:-> new-val . lenses) | ||
(lens-set (apply lens-thrush lenses) target new-val)) | ||
|
||
(define (lens-transform-> target #:-> transformer . lenses) | ||
(lens-transform (apply lens-thrush lenses) target transformer)) | ||
|
||
(define lens-view/thrush lens-view->) | ||
(define lens-set/thrush lens-set->) | ||
(define lens-transform/thrush lens-transform->) | ||
|
||
(module+ test | ||
(define (set-first l v) | ||
(list* v (rest l))) | ||
(define (set-second l v) | ||
(list* (first l) v (rest (rest l)))) | ||
(define first-lens (make-lens first set-first)) | ||
(define second-lens (make-lens second set-second)) | ||
(check-equal? (lens-view-> '((1 2) 3) first-lens second-lens) | ||
2) | ||
(check-equal? (lens-set-> '((1 2) 3) first-lens second-lens #:-> 'two) | ||
'((1 two) 3)) | ||
(check-equal? (lens-transform-> '((1 2) 3) first-lens second-lens #:-> (* 100 _)) | ||
'((1 200) 3)) | ||
) |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,52 @@ | ||
#lang scribble/manual | ||
|
||
@(require lens/doc-util/main) | ||
|
||
@title{lens-view/thrush, lens-set/thrush, and lens-transform/thrush} | ||
|
||
@defmodule[unstable/lens/arrow] | ||
|
||
@deftogether[[@defproc[(lens-view/thrush [target any/c] [lens lens?] ...) any/c] | ||
@defproc[(lens-view-> [target any/c] [lens lens?] ...) any/c]]]{ | ||
Like @racket[lens-view], except that it can take multiple lenses, | ||
which are combined into a nested lens. The argument order is | ||
switched, so that the @racket[target] comes first and the | ||
@racket[lens] arguments come after it. | ||
@racket[(lens-view/thrush target lens ...)] produces the same value as | ||
@racket[(lens-view (lens-thrush lens ...) target)], but can be more | ||
efficient. | ||
The function @racket[lens-view->] is provided as a shorter version. | ||
@lenses-examples[ | ||
(lens-view/thrush '(a b ((c d) e f) g) third-lens first-lens second-lens) | ||
(lens-view-> '(a b ((c d) e f) g) third-lens first-lens second-lens) | ||
]} | ||
|
||
@deftogether[[@defproc[(lens-set/thrush [target any/c] [lens lens?] ... [#:-> new-view any/c]) any/c] | ||
@defproc[(lens-set-> [target any/c] [lens lens?] ... [#:-> new-view any/c]) any/c]]]{ | ||
Like @racket[lens-set], except that it can take multiple lenses, | ||
which again are combined into a nested lens. | ||
@racket[(lens-set/thrush target lens ... #:-> new-view)] is equivalent | ||
to @racket[(lens-set (lens-thrush lens ...) target new-view)], and | ||
@racket[lens-set->] is the shorter version. | ||
@lenses-examples[ | ||
(lens-set/thrush '(a b ((c d) e f) g) third-lens first-lens second-lens #:-> "sea") | ||
(lens-set-> '(a b ((c d) e f) g) third-lens first-lens second-lens #:-> "sea") | ||
]} | ||
|
||
@deftogether[[@defproc[(lens-transform/thrush [target any/c] [lens lens?] ... | ||
[#:-> transformer (-> any/c any/c)]) | ||
any/c] | ||
@defproc[(lens-transform-> [target any/c] [lens lens?] ... | ||
[#:-> transformer (-> any/c any/c)]) | ||
any/c]]]{ | ||
Like @racket[lens-transform], except that it can take multiple lenses, | ||
just like @racket[lens-set/thrush]. | ||
@racket[(lens-transform/thrush target lens ... #:-> transformer)] is | ||
equivalent to | ||
@racket[(lens-transform (lens-thrush lens ...) target transformer)], | ||
and @racket[lens-transform->] is the shorter verison. | ||
@lenses-examples[ | ||
(lens-transform/thrush '(a b ((c d) e f) g) third-lens first-lens second-lens #:-> symbol->string) | ||
(lens-transform-> '(a b ((c d) e f) g) third-lens first-lens second-lens #:-> symbol->string) | ||
]} | ||
|
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters