On Thu, Jan 15, 2015 at 4:33 PM, Alexis King <lexi.lam...@gmail.com> wrote: > As an update, I’ve made a bit more progress on this. I’ve implemented an > impersonate-async-channel function, and I’ve actually included this in the > exports from racket/contract. I also realized the blame information is > correct, it works fine. Most of the other issues remain, as well as a few > new questions: > > There is no impersonate-evt function, so I’m not sure that my implementation > will work. What should I do about this? > I’d assume this needs to be documented/tested as well. Where should those > things be located?
Documentation for contracts is here: https://github.com/plt/racket/blob/master/pkgs/racket-doc/scribblings/reference/contracts.scrbl and in the dependent files. Tests for contracts are here: https://github.com/plt/racket/tree/master/pkgs/racket-test/tests/racket/contract Sam > > On Jan 14, 2015, at 23:44, Alexis King <lexi.lam...@gmail.com> wrote: > > Currently, async channels do not have contracts to check their contents. > This is a problem for Typed Racket, and it prevents typed code from > interacting with code that produces async channels. > > I started looking into how to add contracts to the language, and it seems to > use the chaperones/impersonator system, as I suspected. However, async > channels obviously cannot be impersonated, so I needed to implement that as > well. > > I modified the async-channel struct to use generics to allow it to be > impersonated or chaperoned, which I have exposed by implementing > chaperone-async-channel. I then tried implementing async-channel/c. The > internals of the contract system are a little beyond me, but I got a working > solution by following the example of the box contracts. > > My work thus far can be found here: > https://github.com/lexi-lambda/racket/commit/84b9f3604891f3f2061fb28ed4800af8afa4751b > > First of all, is this a correct approach? Have I done anything wrong, or > should I have done anything differently? I didn’t find much documentation on > the internals of either of these systems, so I mostly went about things as I > found them. > > Second, obviously, not everything is implemented here. Among the additional > necessary changes are: > > I need to implement support for impersonators and impersonator contracts > (right now I’ve only bothered to do chaperones). > I need to implement async-channel/c-first-order and > async-channel/c-stronger. I can probably figure out the latter, but I’m not > even sure what the former is supposed to do. > I need to implement a wrap-async-channel/c macro for the export. I’m not > sure how this works, either. From looking at wrap-box/c, it seems to add > some syntax properties, but I’m not sure what they do or how they work. > Somehow, the blame information has to be correct. Is that what the wrap > function does? Or do the async-channel functions need to be updated to > assign blame? > > > I’d really like to get this working, and I think I’m close, but I’m a little > inexperienced. I’d appreciate any help, even if it’s just pointing me in the > right direction. > > Thanks! > > > > _________________________ > Racket Developers list: > http://lists.racket-lang.org/dev > _________________________ Racket Developers list: http://lists.racket-lang.org/dev
