// An empty 3x4 matrix
const tensorA = tensor([3, 4])
// An empty 4x5 matrix
const tensorB = tensor([4, 5])
const good = multiplyMatrix(tensorA, tensorB);
^
Inferred type is Tensor<readonly [3, 5]>
const bad = multiplyMatrix(tensorB, tensorA);
^^^^^^^
Argument of type 'Tensor<readonly [4, 5]>' is not
assignable to parameter of type '[never, "Differing
types", 3 | 5]'.(2345)
I prototyped this for PotatoGPT [1] and some kind stranger on the internet wrote up a more extensive take [2]. You can play with an early version on the Typescript playground here [3] (uses a twitter shortlink for brevity)[1] https://github.com/newhouseb/potatogpt
This way of thinking is not just unhelpful but even harmful. If one would often benefit from these checks while coding, then they should not be relying on a type checker. They should be thinking more, and writing comments is a great way to do that.
This is especially true because many operations on ndarrays / tensors can yield perfectly valid shapes with completely unintended consequences. When comments are written reasonably well they help avoid these difficult-to-debug, correct-output-shape-but-unintended-result mistakes. Not to mention the additional clear benefit of helping one quickly re-understand the tensor manipulations when coming back to the code weeks or months later.
And more generally, if one can get in the habit of writing these comments before the code, it can help push them away from the write-quickly-now-debug-later mentality. I have seen this bite folks many times, both while teaching ugrad + grad courses and while working at large tech companies.