cannot combine splits merging and streaming?
Hi ! That's missing indeed. We'll try to implement this for the next version :)

I guess we just need to implement #2564 first, and then we should be able to add support for splits combinations is there an update on this? ran into the same issue on 2.17.1.

On a similar note, the keyword `split="all"` also does not work as intended when `streaming=True`.  No update so far, especially since we haven't implemented an efficient way to query `split=train[50%:]` for example. The addition of two splits should be easy though, since we have `concatenate_datasets()` Can you concatenate_datasets that are being streamed now? I was led to believe concatenation works on non streaming datasets only. Yes `concatenate_datasets` works for datasets loaded in streaming mode as well
this does not work:
`dataset = datasets.load_dataset('mc4','iw',split='train+validation',streaming=True)`
with error:
`ValueError: Bad split: train+validation. Available splits: ['train', 'validation']`

these work:
`dataset = datasets.load_dataset('mc4','iw',split='train+validation')`
`dataset = datasets.load_dataset('mc4','iw',split='train',streaming=True)`
`dataset = datasets.load_dataset('mc4','iw',split='validation',streaming=True)`

i could not find a reference to this in the documentation and the error message is confusing. also would be nice to allow streaming for the merged splits