Awkward array support

[DanielMedic]

The now obsolete anndata package can handle awkward arrays, e.g. adata$obsm$airr <- my_airr where airr is an "awkward.highlevel.Array" object. But in anndataR, this fails with the error:

Error in `private$.validate_aligned_mapping()`:
! Unexpected shape for obsm[['airr']]
ℹ Expected [n], got []
Run `rlang::last_trace()` to see where the error occurred.

where n is the value of nrow(adata). It appears that private$.validate_aligned_mapping does not know how to get the dimensions of airr, whereas the equivalent check in anndata does.

[lazappi]

Because CRAN {anndata} wraps Python it gets these features for free while for {anndataR} we have to implement them separately. This is something we should add but it's probably not a priority. In the meantime, it should be noted somewhere that this isn't supported yet.

[DanielMedic]

@lazappi, thanks for the explanation!