v0.7.0

[0.7.0] - 2022-02-19

This release adds several new features: support for evaluating ZX-diagrams as tensor networks using the hypergraph contraction methods of quimb, basic support for interacting with the Rust port of PyZX quizx, support for 'hybrid' ZX-diagrams that contain classical wires and measurements, as well as several heuristics for trying to optimise the CNOT count of a circuit that is to be extracted from a ZX-diagram.

There is one small breaking change, which is that Graph.inputs and Graph.outputs are now methods that return a list, instead of being lists themselves.

Added

• Added support for evaluating ZX-diagrams as tensor networks in quimb (courtesy of
  Paul Tirlisan).
• Added quizx backend for the Graph class.
• Graph vertices can now carry a ground generator. This makes it possible to represent measurements and classical control in the diagrams. See the accompanying paper (courtesy of ABorgna).
• Added extract.lookahead_extract that uses heuristics to extract circuit with less CNOT gates (courtesy of VladMoldoveanu).
• Added local_search submodule for doing simulated annealing on rewrites of a ZX-diagram to try to get it to be extracted with less CNOTS (courtesy of Ryan Krueger).
• Added new rewrite rule for ZH-diagrams hsimplify.par_hbox_intro_simp() that can remove some H-boxes.
• Added several new rewrite rules to basicrules and mbqc.
• QASM parser: added support for controlled-Hadamard and controlled-Z phase gates.
• QC parser: added support for SWAP gates (courtesy of wdomitrz).
• Added Graph.set_inputs() and Graph.set_outputs() to set a list of vertices to be the inputs/outputs of a diagram.
• Added Graph.num_inputs() and Graph.num_outputs() to get the number of inputs and outputs of a diagram.

Changed

• Graph.inputs is now a method that returns a list of inputs, instead of Graph.inputs being a list itself. The same for Graph.outputs.

Fixed

• Several incorrect scalars were fixed in ZH-diagram rewrite rules.