Support classical Futures (e.g., for decoding)

[perlinm]

In the context of quantum error correction, decoding takes time. My understanding is that if I measure some qubits and query a decoder in a guppy program, the entire quantum program stops until the decoder is finished. What is more, I believe routines like DD do not account for decoding latency, which might make them less effective if the time to decode is >= the time scale for other quantum operations (say, ~1 ms). It would be nice for the decoding to occur concurrently with the quantum program, which (aside from parallelizing the program, which is always nice) increases the "time budget" that a decoder has to do its business.

Is that currently possible? If not, what would it take to make this possible? I imagine guppylang would need to support classical Futures, which would be able to run concurrently with other parts of the program, and only cause everything to stop if necessary when the Future.result is actually needed.