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contract_network_along_path

quantrs2_sim::tensor_network::contraction

Function contract_network_along_path 

Source 
pub fn contract_network_along_path(
    tensors: &mut HashMap<usize, Tensor>,
    connections: &mut Vec<(TensorIndex, TensorIndex)>,
    path: &ContractionPath,
    next_id: &mut usize,
) -> QuantRS2Result<Tensor>
Expand description

Contract a tensor network to a single tensor by executing the given contraction path.

The connections list defines the bonds of the network; each bond is turned into a shared axis label. The path gives the order of pairwise contractions — for each step (id1, id2) the two tensors are contracted over all axes they share (matching labels), and the merged tensor takes the place of id1 (the same “merge into the first ID” convention produced by calculate_greedy_contraction_path). Any tensors left uncontracted by the path are folded together via outer products.

This performs the real contraction arithmetic via [contract_pair_multi]; it no longer returns an arbitrary existing tensor.