Right now, there's not much support for struct properties at all in Typed Racket. So this would probably be a non-trivial amount of work.
Sam On Tue, Jul 29, 2014 at 3:46 AM, <berthold.bae...@dlr.de> wrote: > So, there is currently no way make math/array serializable at all -- even > when it would be ok to get an inefficient wrapped array as a result from > deserialize? As far as understand, what hinders me from writing a simple > typed wrapper for serialize/deserialize is that a typed struct does not > support the #:property prop:serializable (simply ignored) at all and hence > serialize complains about a non serializable value. Is this correct and would > it be possible to add this property options with little effort? > > Berthold > > > On 24.07.2014, at 14:52, Sam Tobin-Hochstadt <sa...@cs.indiana.edu> wrote: > >> On Thu, Jul 24, 2014 at 7:21 AM, Berthold Bäuml <berthold.bae...@dlr.de> >> wrote: >>>> De-serializing an array of numbers and then passing it to typed code >>>> would produce a wrapper, not a first-order check, and so would be very >>>> expensive. >>> >>> Even when first-order checks would be possible the cost of such a check >>> would be significant in our application. We wan to use >>> serialization/deserialization to send data between programs -- when running >>> on the same computer the I/O cost (local sockets) would be almost >>> negligible. >>> >>> Would it be possible to have a typed serialization in the near future? >> >> I think the Racket `serialize` API is likely to be higher-cost than >> that, even without considering Typed Racket. >> >>>> What you want is something that can tell that the untyped reference is >>>> dead after value is passed to typed code, so that a first-order check >>>> can be used. This would require something new from Racket in the form >>>> of a revocable reference. >>> >>> Does this also hold for immutable arrays? In this case a first-order check >>> should suffice in principle. >> >> Yes, for immutable arrays represented as flat data (not functions) the >> checks would not require wrappers. >> >> Sam >> >>> Berthold >>>> >>> >>>> >>>> On Wed, Jul 23, 2014 at 11:52 AM, Matthias Felleisen >>>> <matth...@ccs.neu.edu> wrote: >>>>> >>>>> Let's assume we serialize arrays of numbers, which is what I assume the >>>>> background to the question is. In that case, the answer isn't all that >>>>> obvious to me. >>>>> >>>>> >>>>> >>>>> >>>>> On Jul 23, 2014, at 11:47 AM, Sam Tobin-Hochstadt <sa...@cs.indiana.edu> >>>>> wrote: >>>>> >>>>>> That really depends what the contracts are, and if they're first-order. >>>>>> >>>>>> Sam >>>>>> >>>>>> On Wed, Jul 23, 2014 at 11:45 AM, Matthias Felleisen >>>>>> <matth...@ccs.neu.edu> wrote: >>>>>>> >>>>>>> Will these costs dominate the cost of I/O here? >>>>>>> >>>>>>> >>>>>>> On Jul 23, 2014, at 11:37 AM, Sam Tobin-Hochstadt >>>>>>> <sa...@cs.indiana.edu> wrote: >>>>>>> >>>>>>>> Unfortunately, I think that strategy would incur substantial overhead >>>>>>>> for things like serialization of large arrays. >>>>>>>> >>>>>>>> Sam >>>>>>>> >>>>>>>> On Wed, Jul 23, 2014 at 11:28 AM, Matthias Felleisen >>>>>>>> <matth...@ccs.neu.edu> wrote: >>>>>>>>> >>>>>>>>> On Jul 23, 2014, at 11:10 AM, Neil Toronto <neil.toro...@gmail.com> >>>>>>>>> wrote: >>>>>>>>> >>>>>>>>>> On 07/16/2014 10:25 AM, Berthold Bäuml wrote: >>>>>>>>>>> Hi, >>>>>>>>>>> >>>>>>>>>>> will there be serialization support for math/array and math/matrix >>>>>>>>>>> in the near future? As far as I understand in principle it should >>>>>>>>>>> be possible at leas in a straight forward way as there are >>>>>>>>>>> already the routines array->list and list->array. >>>>>>>>>> >>>>>>>>>> Sorry it's taken so long to reply. Part of the problem is that >>>>>>>>>> `racket/serialize` isn't typed: >>>>>>>>>> >>>>>>>>>> #lang typed/racket >>>>>>>>>> >>>>>>>>>>> (require racket/serialize) >>>>>>>>>>> serialize >>>>>>>>>> Type Checker: missing type for identifier; >>>>>>>>>> consider using `require/typed' to import it >>>>>>>>>> identifier: serialize >>>>>>>>>> from module: racket/serialize in: serialize >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> This and the fact that the array struct types are declared in Typed >>>>>>>>>> Racket makes adding serialization tricky at best. Also, it would >>>>>>>>>> only work in untyped Racket. >>>>>>>>>> >>>>>>>>>> Generally, deserializing is hard to make type-safe, and nobody has >>>>>>>>>> taken it up yet for Typed Racket. Occurrence typing should help, but >>>>>>>>>> would require `deserialize` to take a predicate argument (like the >>>>>>>>>> second argument to `list*->array`), which it currently doesn't do. >>>>>>>>> >>>>>>>>> >>>>>>>>> Lucky us. I often leave the I/O parts of my programs untyped (I write >>>>>>>>> either highly imprecise unchecked signatures or I don't provide >>>>>>>>> types). >>>>>>>>> ____________________ >>>>>>>>> Racket Users list: >>>>>>>>> http://lists.racket-lang.org/users >>>>>>> >>>>> >>>> >>>> ____________________ >>>> Racket Users list: >>>> http://lists.racket-lang.org/users >>> >>> -- >>> ----------------------------------------------------------------------- >>> Berthold Bäuml -- Head of Autonomous Learning Robots Lab >>> DLR, Robotics and Mechatronics Center (RMC) >>> Münchner Str. 20, D-82234 Wessling >>> Phone +49 8153 282489 >>> http://www.robotic.de/Berthold.Baeuml >>> >>> >>> >>> ____________________ >>> Racket Users list: >>> http://lists.racket-lang.org/users > > -- > ----------------------------------------------------------------------- > Berthold Bäuml -- Head of Autonomous Learning Robots Lab > DLR, Robotics and Mechatronics Center (RMC) > Münchner Str. 20, D-82234 Wessling > Phone +49 8153 282489 > http://www.robotic.de/Berthold.Baeuml > > ____________________ Racket Users list: http://lists.racket-lang.org/users
