[RFC] [Tensor] Extracting slices from `tensor.collapse_shape`

[nicolasvasilache]

Thanks for spelling out the use case, affine seems like a reasonable landing place for now.

@stellaraccident

My first thought was “this would be the kind of thing that would be put in the ‘index’ dialect that we decided not to make when splitting things up”. Agreed that ‘affine’ is the closest we have right now.

+1 I expect we’ll start needing an ‘index’ dialect soonish.