feat: to/from TensorFlow Tensor

[maxymnaumchyk]

No description provided.

[maxymnaumchyk]

Note: as discussed here when converting a TensorFlow Tensor into Numpy array with tensor.numpy() it creates a copy since Numpy is mutable and TensorFlow Tensor is not.

When converting Awkward Array to TensorFlow (while on CPU), this function: tf.convert_to_tensor(numpy_array) also makes a copy. I suppose for the same reason.

[codecov]

Codecov Report

Attention: Patch coverage is 30.15873% with 44 lines in your changes missing coverage. Please review.

Project coverage is 82.06%. Comparing base (b749e49) to head (fbcf571).
Report is 182 commits behind head on main.

Files with missing lines	Patch %	Lines
src/awkward/operations/ak_to_tensorflow.py	28.12%	23 Missing ⚠️
src/awkward/operations/ak_from_tensorflow.py	27.58%	21 Missing ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
src/awkward/operations/__init__.py	100.00% <100.00%> (ø)
src/awkward/operations/ak_from_tensorflow.py	27.58% <27.58%> (ø)
src/awkward/operations/ak_to_tensorflow.py	28.12% <28.12%> (ø)

... and 158 files with indirect coverage changes

[jpivarski]

This looks perfect! Thank you again! This looks complete, and if you agree, I'll merge it into main.

On copying data from TensorFlow to NumPy: it might not be_technically_ necessary, since NumPy arrays have flags and can be marked as not writable. Thus, a NumPy array could zero-copy view a TensorFlow tensor in RAM (not GPU memory), if TensorFlow has stable pointers. Some systems, such as Java, copy data to different locations to defragment their memory use, which causes simple pointers (static integers) to get out of date. If TensorFlow does that, then it has to copy when converting to NumPy, even with NumPy's "writable" flag.

But this is probably out of our hands, since we have to rely on what functions TensorFlow gives us. They might have stable pointers that could be viewed as a non-writable NumPy array and yet just don't give us a function to do that—all we could do is ask them to add such a thing to their library (which we won't, because it's not such a big deal).

[jpivarski]

(If you agree and it's ready to be merged, write a comment, rather than an emoji, since I get emails for comments but not emojis. Thanks!)

[jpivarski]

It looks done to me. I'm going to merge it. Thanks!