[ogpx] (Not) serializing LLSD default values

["Hurliman, John" <[e-mail]>]

I'm considering a change in the C# LLSD implementation (OpenMetaverse.StructuredData) to skip serialization of default values inside maps. For example, the following structure:

{
    "zero":0,
    "one":1,
    "empty_string":"",
    "hello_string":"hello world"
}

Would become:

{
    "one":1,
    "hello_string","hello world"
}

>From my reading of the draft (and our current implementation), those two serializations should be equivalent. Do the current Linden Lab implementations handle that correctly? The only problem I see with the C# implementation is that it would make some incompatible typecasts work when they shouldn't. For example, the receiving end could then read key "zero" as an LLSD array and it would work, where the value "0" usually shouldn't be convertible to an array. So it assumes some level of coherence between the sender and receiver, which I think is acceptable.

I would look at the source of the other implementations myself, but the last time I checked the PHP implementation was sorely out of date and the C++ implementation was not under a liberal license.

John