transpose key of RomanNumeral

[malcolmsailor]

Fixes the issue in #1413. I closely modeled RomanNumeral.transpose() on Harmony.transpose().

[coveralls]

Coverage decreased (-0.06%) to 93.011% when pulling 4c71bab on malcolmsailor:rn-transpose into 00971f4 on cuthbertLab:master.

[mscuthbert]

why couldn't this be self.key.transpose(value, inPlace=True) ?

[malcolmsailor]

That's what I had in my initial commit (a40e41a) but I changed it based on the discussion in #1413 and your feedback at #1413 (comment).

[mscuthbert]

ah okay -- yes, we solved the problem in RomanText but not elsewhere, my bad.

[mscuthbert]

for this to work, self has to be annotated with T as well.

[mscuthbert]

see Harmony L 2338

[malcolmsailor]

OK, fixed, but mypy didn't seem to be complaining. The "x" seems to be because coverage decreased slightly. (Not quite sure why since both inPlace=True and inplace=False are tested in the RomanNumeral.transpose() doctest.)

[mscuthbert]

I didn't see that this was ready because it was marked with an "x" -- reviewed now -- one fix needed to not get incorrect typing, one nice to have.

Consider looking at the paradigm in key.Key transpose where the two inPlace options are typed differently so that it's obvious to the typing system whether to expect a RN or None to be returned.

[malcolmsailor]

mypy is failing now:

music21/audioSearch/__init__.py:529: error: Incompatible return value type (implicitly returns "None", expected "List[int]")
music21/interval.py:363: error: Incompatible return value type (implicitly returns "None", expected "Tuple[Literal['C', 'D', 'E', 'F', 'G', 'A', 'B'], int]")
music21/stream/iterator.py:796: error: A function returning TypeVar should receive at least one argument containing the same Typevar
Found 3 errors in 3 files (checked 259 source files)

I don't get these errors on my local machine; I just tried merging the current master into the branch and I still don't get them. So I'm not sure whether this PR is somehow introducing them?

[mscuthbert]

mypy is failing now:

music21/audioSearch/__init__.py:529: error: Incompatible return value type (implicitly returns "None", expected "List[int]")
music21/interval.py:363: error: Incompatible return value type (implicitly returns "None", expected "Tuple[Literal['C', 'D', 'E', 'F', 'G', 'A', 'B'], int]")
music21/stream/iterator.py:796: error: A function returning TypeVar should receive at least one argument containing the same Typevar
Found 3 errors in 3 files (checked 259 source files)

I don't get these errors on my local machine; I just tried merging the current master into the branch and I still don't get them. So I'm not sure whether this PR is somehow introducing them?

They must have upgraded their version of mypy today and it now finds errors that it didn't before. Those aren't from your work, so we can go and merge and I'll squash them separately. THANKS!

[mscuthbert]

oh, wait I turned on merge protection to prevent me from accidentally committing to master and I can't overrule this without some major tweaking (2-factor, etc.) so I'll get a separate fix in and then merge this. Sorry for the delay.

[mscuthbert]

Closing and reopening to get a clean board.