Jacqueline Firth

I've wanted to redo the lens library completely for a few years now, as part of Rebellion. Maybe some modules like this: - `rebellion/optic/lens` - `rebellion/optic/prism` - `rebellion/optic/traversal` - `rebellion/optic/converter`...

Asked about this on [racket-users](https://groups.google.com/d/topic/racket-users/Y1P-8zDSbS8/discussion) but haven't received much response yet. Adding the link here for posterity.

I can't think of a use case for `reducing`, it seems to me every use case wants `reducing-nonempty` instead. So to keep the API simpler I'll only provide one `reducing`...

Note: needs to be smart enough to parse `(\\d+)` into a `number?` instead of a string of digits.

On failure, would you want information about why the match failed? Maybe using [`result`](https://docs.racket-lang.org/rebellion/Results.html) objects instead of `present` and `absent` would be the way to go.

Idea: a `#:repeat?` argument that, when true, is equivalent to wrapping the transducer body in a loop that runs forever. This is similar to #337 and to [`infinite-generator`](https://docs.racket-lang.org/reference/Generators.html#(form._((lib._racket%2Fgenerator..rkt)._infinite-generator))).

I started working on a [functional graph API](https://github.com/jackfirth/advent-of-code-2019/blob/master/graph.rkt) as part of my Advent of Code solutions. It's got most of the basics implemented and it's not _super_ inefficient, as graphs...

Update: guard functions should probably match the contract `(-> wrapper-type? (-> any/c any/c))`, just to get any allocation related to error messages out of the way at type creation time.

Is there a way to get `read` to produce user-defined data types? I know `prop:serializable` exists for binary serialization, but I don't know of any equivalent for `read`.

Could you describe your use case more?