[vwrap] What abstract type systems already exist?

[Boroondas Gupte <[e-mail]>]

On 05/08/2011 03:47 AM, Morgaine wrote:
> ADT means Abstract Data Type.
> [...]
> No mystery there, it has been so for decades of common usage in
> Computing. :-)
On 05/09/2011 03:53 PM, Meadhbh Hamrick wrote:
> hmm... don't think me or mark lentczner coined the term "abstract type
> system." i was used by the OMG and Microsoft long before we used it.
On 05/09/2011 03:58 PM, Morgaine wrote:
> Aye, that phrase has been in use for as long as types systems have
> existed.

As the concepts of both, ADTs and ATSs have apparently existed longer
already than I assumed, I guess there must be ATSs other than LLSD. As a
basis for decisions, it'd be useful to have some overview. So my
question is:
*What abstract type systems do currently exist *("exist" as in published
and sufficiently documented. Don't have to be formally standardized,
though if they are, that's a plus.)*and how do they compare to LLSD?*

For each such ATS, it'd be useful to know:

    * How flexible is it?
      (Could it be used for VWRAP? For that, its set of types probably
      must already be designed for general purpose or (like LLSD) with
      typical virtual world data in mind.)
    * Is it extensible? How does the extension mechanism work?
    * Are there serializations defined for it? If so, which ones?
    * How entangled is the ATS itself with the serializations?
    * How simple is it? (Both conceptually and for implementors of
      (de)serializers etc.)

Once we have collected that, we'd be in a better position whether to use
LLSD (as-is) or one of the other systems or whether to create our own
(probably based on LLSD and/or other ones).

Cheers,
Boroondas