[racket] serialization of math/array

From: Matthias Felleisen (matthias at ccs.neu.edu)
Date: Wed Jul 23 11:52:41 EDT 2014

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 <samth at 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
> <matthias at 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 <samth at 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
>>> <matthias at ccs.neu.edu> wrote:
>>>> 
>>>> On Jul 23, 2014, at 11:10 AM, Neil Toronto <neil.toronto at 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).
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>> 



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