Alex Knauth

When I set up `alias.mp4` as a file alias or soft-link to another `.mp4` file, and click the DrRacket video preview button on this program: ```racket #lang video (clip "alias.mp4")...

testing forms?

1

Would you want a library for testing that you would have to require or import, or would you want it to be provided by the language? Would you want to...

The documentation for `dag-shortest-paths` should say whether or not it works on dags with negative edge weights. And in the case that it doesn't handle them, should a version be...

add check-big-bang

7

This adds `check-big-bang` and `check-big-bang*` to `2htdp/universe`. A usage of `check-big-bang` looks like: ``` racket (check-big-bang (main (make-posn 0 0)) [(make-tick) (make-posn 1 1)] [(make-key "right") (make-posn 6 1)] [(make-tick)...

add isomorphism-cond and isomorphism-join

1

This pull request adds `isomorphism-cond`, `isomorphism-join`, `lazy-isomorphism`, and `rec-isomorphism`. TODO: Add docs. Examples: ```racket (define (map-iso item-iso) (rec-isomorphism the-map-iso (isomorphism-cond [empty? identity-lens empty?] [cons? (isomorphism-join cons cons [first item-iso first]...

add add-lens, subtract-lens, and modulo-lens

3

I still need to provide it from `unstable/lens` and add it to the unstable docs. ``` racket > (lens-view (add-lens 5) 3) 8 > (lens-set (add-lens 5) 3 8) 3...

Modulo lens

3

Something like: ``` racket > (lens-view (modulo-lens 10) 16) 6 > (lens-set (modulo-lens 10) 16 9) 19 ```

add struct->struct-lens

2

see https://github.com/jackfirth/lens/issues/267

Matrix lenses?

2

Should there be a lens constructor for matrices as functions from column-vectors to column-vectors? For square invertable matrices it could be an isomorphism lens. ``` racket (define (matrix-lens/invertable m) (define...

struct->struct lens?

1

Something like this: ``` racket (struct foo (a b c)) (struct bar (x y z)) (define foo->bar-lens (struct->struct-lens foo bar)) > (lens-view foo->bar-lens (foo 1 2 3)) (bar 1 2...