.Net: VectorStoreRecordVectorProperty type restrictions

[markwallace-microsoft]

The following​ code causes an exception:

→ new VectorStoreRecordVectorProperty("DescriptionEmbedding", typeof(float)) { Dimensions = 4, DistanceFunction = DistanceFunction.CosineDistance, IndexKind = IndexKind.Hnsw },

The embedding is an array, but alternative types also fail:
typeof(float[]) → exception
typeof(List) → exception
typeof(ReadOnlyMemory) → works
The type constraint seems too strict. It should support float[], List, IEnumerable, etc.

[markwallace-microsoft]

@dluc our plan is to align with the abstractions being defined for M.E.AI. Take a look at this issue for the details: #10492

[dluc]

We had these exact pain points and discussions three years ago when prototyping SK :-)

Back then, we created a powerful and flexible Embedding struct with implicit operators, enbling readable code and seamless integrations. We even anticipated this concept becoming part of the official .NET libs.

It's unclear why we're discarding that work, it seems like a regression. I've commented on the other ticket; hopefully, the team can reach a compromise to reduce boilerplate. Otherwise, developers might resort again to extension methods or similar approaches to abstract away this complexity.

[roji]

The type constraint seems too strict. It should support float[], List, IEnumerable, etc.

As I wrote in #10492 (comment), it makes no sense to me to represent embeddings as List or IEnumerable, since they're opaque results of an embedding model that should never need to be mutated like collections; I'm happy to be convinced otherwise, but I'd like to see some proposals of concrete usages requiring List/IEnumerable. For float[] specifically I could possibly see it making sense to accept that for ease-of-use, I'd need to think a bit more about it.

Back then, we created a powerful and flexible Embedding struct with implicit operators, enbling readable code and seamless integrations. We even anticipated this concept becoming part of the official .NET libs.

Similar to the above, what kind of implicit operators would you expect from an Embedding type?

[roji]

The final version of MEVD released at Build supports ReadOnlyMemory<float>, float[] and Embedding<float> (and same for other types, e.g. Half). As above, I don't think we should support arbitrary IEnumerables or Lists, but this is something we can revisit if there's user request for these.