Re: protobuff for Ada

[Per Sandberg <per.s.sandberg@bahnhof.se>]

Well

 From my perspective absolutely biggest flaw with technologies like 
protobuf is:
* Its backed by a large corporation.
* The technology is well known.
* 99.9% of the programming population think that they are the salvation 
to serialization.
* The licensing is open.

And on top.
* The are significantly more then one project where the lack of protobuf 
support has ruled out Ada as implementation technology.

/And my intent was to eliminate at least the last points even if the 
technology is inferior.

/P


On 12/29/18 12:05 PM, Dmitry A. Kazakov wrote:
> On 2018-12-29 06:53, Shark8 wrote:
> 
>> Though, it should be noted that ASN.1 is *probably* the better 
>> technology in cases where ProtoBufs are being considered:
>> http://ttsiodras.github.io/asn1.html
> 
> Sorry to disappoint you in this festive time, but this approach has the 
> same fundamental flaw as prepared SQL statements do. You have to bind 
> native Ada objects to protocol/serialized/persistent objects forth and 
> back. This does not work well in practice. In fact, it barely work at 
> all considering the overhead and hazards of type conversions.
> 
> A different approach is Ada's representation clauses which describe both 
> objects same. Beyond simple textbook cases that does not work either.
> 
> The best practical method so far is using manually written stream 
> attributes. Unfortunately it has shortcomings too:
> 
> 1. Reuse is limited and composition is unsafe because stream attributes 
> are non-primitive operations.
> 
> 2. Introspection is almost non-existed. Only tagged types could have it.
> 
> 3. No support of error handling and versioning. Though it is possible to 
> do manually that is extremely error-prone and totally lacks static 
> verification when the number of test cases is huge to potentially 
> infinite. Even worse, the offending cases do not show up in a normally 
> functioning system. So, when detected, it is always too late.
> 
> P.S. Needless to say, the problems 1-3 fully apply to other two methods 
> as well.
> 
> P.P.S. And nothing was said about referential and recursive types...
>