Indeed it does work on the command line

I’ve just cargo-cult’ed a couple of PR’s to add racket to the languages for the icfp2020 competition - I have no idea if they are right so if anyone knows anything about docker I’d appreciate it if they took a look at my PR’s! https://github.com/icfpcontest2020/dockerfiles/issues/63

(all the links and details are in the PR above :point_up_2:)

@gfb The problem still happens with the repl in DrRacket when tried parameterizing read-cdot to #f unfortunately. Doesn’t mean this isn’t part of the problem though

cc @notjack

Is factorial still working on Racket CS? From Racket BC:

(Just noticed this comment: https://github.com/racket/math/blob/master/math-lib/math/private/number-theory/factorial.rkt#L9 )

Flonums are the same in BC and CS, so there should be no problem (and I get the same results as your screen shot). You were maybe thinking about the fact that the fixnum ranges are different?

Yes.

No problems then.

:relieved:

Is there any raco tool or similar to look for functions without call sites?

https://github.com/jbclements/racket-no-brainer might do it

Working on a library for converters (objects containing a pair of functions like string->number and number->string). Anyone else made/used something similar? Example: (define string<->number (make-converter string->number number->string)) > (convert-forward string<->number "42") 42 > (convert-backward string<->number 5) "5"

Frtime?

(just guessing)

like, frtime might currently use something like this?

Maybe? Since it needs to do these types of conversions

I was also thinking code that deals with HTTP APIs, since they need to turn stuff into json and back

MrEdDesigner needs to do these conversions also

Or needs to convert many kinds of values from/to gui and from/to file

(well the latter is easy of course)

parsing stuff too

Here’s something I started way back https://github.com/samdphillips/codecs/blob/master/codecs.rkt

Ideally you could compose the codecs etc.

oh neat

It was barely a start at the time

I started a thing like that too and even used the same name

you got farther than me - I just wrote some docs

plot has invertible functions https://docs.racket-lang.org/plot/ticks_and_transforms.html#(part._invertible)

oh neat!

a use case in the wild

update: converters are implemented and mostly documented! woo!

There’s also bidirectional transformation which is a more general concept.

lenses and such?

yep

I think this converter would be really useful if we can do algebra with it, like composition and inversion

then you my friend are in luck

converter-pipe chains converters together, converter-flip swaps the direction of a converter

also, they support contracts - you can do (converter/c foo? bar?)