unable to expand ~ 100 element fast.ai list (`L`) in environment pane

[jjallaire]

Does this issue occur when all extensions are disabled?: Yes/No

For the following code:

from fastai.text.all import untar_data, URLs, get_text_files, coll_repr, WordTokenizer, first

path = untar_data(URLs.IMDB)
files = get_text_files(path, folders = [
    'train',
    'test',
    'unsup'
])

txt = files[0].open().read(); txt[:75]

spacy = WordTokenizer()
toks = first(spacy([txt]))

The toks variable is not expandable in the Environment pane:

[petetronic]

It looks like toks is of a custom type fastcore.foundation.L which doesn't derive from Python's typical collections (list, tuple). We cannot assume all iterable types have "children" from an environment inspector perspective, but widening the logic to consider the presence of an __iter__ implementation - but not one of the unwanted types like string, bytearray, etc - would allow expansion.

[petetronic]

Confirmed this is now fixed in main after https://github.com/rstudio/positron/pull/1083