> Torch, Jax
Both of these "make it available". Just because people don't know how to use/find them doesn't mean they're not "available".
> Eigen
This is not an ML anything, it's a linear algebra library.
> like commenting '# (b, n, t)' on every line, or suffixing shapes to variable names
There's a difference between tracking shapes in the compiler and specifying shapes in the model.
I think we're talking at cross purposes. The reason I'm excited about the Pyrefly work is that it leverages the type system to infer array shapes statically, which makes it simpler to reason about them when you're writing the code and catch bugs. The fact that people have developed these janky approaches to shape tracking suggests that there's a gap to be filled.
Jax and Torch don't do that statically. They obviously have to do it at runtime, but that doesn't address this particular issue. I mention Eigen because array shape hinting is generally useful for any linalg library, not purely for ML applications.