Best way to tensor reshaping about tensoroperations.jl HOT 2 OPEN

This would indeed be a possibility which I have also considered, but I have not implemented it yet. Maybe at some point. One issue that holds me back is how to do/specify the reverse reshaping, i.e. where a single dimension of the tensor gets split into two or more, with easy syntax.

from tensoroperations.jl.

I made a package which does this, and some other things. The notation you suggest works, as does the more compact \ for combining indices:

using TensorOperations; using TensorSlice
B = rand(2,3); C = rand(3,4,5); D = rand(5,6,7,8);
@tensor A[a,e,c,g,f] := B[a,b] * C[b,c,d] * D[d,e,f,g];

@shape Z[a\e\c, g\f] := A[a,e,c,g,f];

Unlike @tensor it doesn’t do any of the work, it just writes the same reshape() command you did. Which I believe should not allocate much memory.

from tensoroperations.jl.