Moving to Swift

[Morten Dahl]

Explore to what extent it makes sense to move (parts of) the TFE codebase Swift, and if so, outline what this would look like.

Pros:

• strong typing system
• better integration of custom kernels/MLIR

Cons:

• performance seems to be worse in S4TF (at the current stage): tensorflow/swift-apis#630

Questions:

• is S4TF suitable for (expressing) distributed computations?
• how would S4TF fit together with TFE compiler and runtime?
• how easy is it to use Swift code from Python, or would it require users moving to Swift as well?