Does anyone know the recipe for a functional hash table in Java? I feel like my google-fu is terrible because of different ideas about functional/persistent mean to java people

You gotta google “purely functional” :slightly_smiling_face:

@jeapostrophe maybe https://github.com/usethesource/capsule

from this paper https://michael.steindorfer.name/publications/oopsla15.pdf

For the Mac users out there: if you hide DrRacket (DrRacket menu -> Hide DrRacket or cmd-H), does it just immediately pop back up? That’s what I’m seeing on High Sierra

I’m only seeing this on one computer and it’s the only one I have with High Sierra, so I’m trying to narrow down the problem before I open an issue

@tonyg @jeapostrophe Is this an internal package-server error? https://pkgs.racket-lang.org/package/handy

a question for my curiosity, how does DrRacket’s documentation pop up (or expand in?) found at the upper right corner determine what topic to automatically display? It seems to choose based on what I had just typed in, I was thinking it would be nice if it instead chose based on where I placed the caret. Is there a way to configure the documentation system to look up based on caret’s location?

@mflatt Yes, I’ll fix it

@bmastenbrook I’m not on high sierra, and it does the same here. It doesn’t pop up… the next app in line stays forefront, but it does become immediately available. Please file a bug on racket/drracket

@abmclin it does show the documentation based on where the text cursor is. Either on what you just typed, or clicked on.

does anyone know how contract combinators use the #:stronger argument?

I tried adding some prints to racket/contract/private/box.rkt, and then I tried running this program: #lang racket (for/fold ([acc (box 'hello)]) ([i (in-range 4)]) (contract (box/c symbol?) acc 'pos 'neg)) and my prints aren’t showing up, so it looks like box/c-stronger isn’t getting called

I had thought something like contract-stronger? would get called any time a value with a contract got a new contract … so (contract (box/c A) (contract (box/c B) val 'pos 'neg) 'pos 'neg) should call stronger? one time

@ben I’m not actually sure it’s used anywhere other than this bit in the instanceof/c projection to avoid building up contracts: https://github.com/racket/racket/blob/master/racket/collects/racket/private/class-c-old.rkt#L1297

thanks @dan , that matches what I’m seeing. This is very surprising to me.

@mflatt fixed now!