[Pyobjc-dev] Bridging enumerated types

[Leigh S. <le...@to...>]

The Python-ObjC works really well for interfacing the MusicKit (non-GUI) to
Python, thanks to the developers!

One issue we face is that the MusicKit uses a very large collection (200
odd) of enumerated types for musical note parameters (pitch, duration,
synthesis parameters etc). It would be really nice to define these within
Python, but to avoid synchronizing between two code bases, it would be nicer
to have them automatically derived from the C source.

Two approaches come to mind, either I create a C function that includes the
params.h file (containing the enums) and then exports them via the usual
Python C bridge or I write a python script to read a header file, extract
all the enums (including integer assignments) and create the variables then.

The issues I can see are the former could require a lot of repetitive code
(possibly automatically created using sed/Python/perl) and would require
that binary to be complied and placed into the standard Python library area.
Each program would then need a "import MusicKit" statement, which could (I
assume) do the NSBundle.load('MusicKit.framework') statement.

The latter parsing approach would need to create all the variables at run
time (obviously possible, but I currently lack that knowledge of Python) and
would follow the NSBundle.load('MusicKit.framework') statement with
something like enumParse('MusicKit.framework/Headers/params.h').

Perhaps there is already some similar solution since this is not ObjC
specific, any bridge to a large C code base using many enums would have the
same issue. Of course I'd look to contribute the solution to either pyobjc
or the standard Python archive, depending on where it is best located.

Any suggestions?