Accessibility: Structured interval output in `rslib`

Anki Development
1

Would this be appropriate for rslib? We can implement this as a patch for AnkiDroid if you’d prefer.

AnkiDroid would like to make the times on the answer buttons accessible: 2m should read as ‘2 minutes’, not ‘2 meters’.

Would it be possible to add a backend API which we can query to obtain structured input for the intervals on the answer buttons, or have this data added to an existing call. Something along the lines of this pseudocode:

{
    "amount": 2.0, // rounded to the same precision as the answer buttons
    "unit": "MINUTES",
    "flags": [
        "learn ahead limit; (end); etc..."
    ]
}

Additional Context

Using FormatTimespanRequest.INTERVALS is possible, but the spoken values and the displayed values would mismatch, as they are rounded differently.

In addition: the learn ahead limit specifier (<) and (end) would need special care.

from anki.i18n_pb2 import FormatTimespanRequest

print(mw.col.format_timespan(90, context=FormatTimespanRequest.ANSWER_BUTTONS)) # 2m
print(mw.col.format_timespan(90, context=FormatTimespanRequest.INTERVALS)) # 1.5 minutes