src/setups/decompositions/swap2cnot.js

import {Compute, Uncompute} from '../../meta/compute';
import {CNOT} from '../../ops/shortcuts';
import {tuple} from '../../libs/util';
import {Control} from '../../meta/control';
import DecompositionRule from '../../cengines/replacer/decompositionrule';
import {SwapGate} from '../../ops/gates';

const _decompose_swap = (cmd) => {
  const ctrl = cmd.controlQubits
  const eng = cmd.engine
  Compute(eng, () => {
    CNOT.or(tuple(cmd.qubits[0], cmd.qubits[1]))
  })
  Control(eng, ctrl, () => {
    CNOT.or(tuple(cmd.qubits[1], cmd.qubits[0]))
  })
  Uncompute(eng)
}

export default [
  new DecompositionRule(SwapGate, _decompose_swap)
]