qiskit/dagcircuit/dagcircuit.py
def _check_edgemap_registers(self, edge_map, keyregs, valregs, valreg=True):
        """Check that wiremap neither fragments nor leaves duplicate registers.

        1. There are no fragmented registers. A register in keyregs
        is fragmented if not all of its (qu)bits are renamed by edge_map.
        2. There are no duplicate registers. A register is duplicate if
        it appears in both self and keyregs but not in edge_map.

        Args:
            edge_map (dict): map from (reg,idx) in keyregs to (reg,idx) in valregs
            keyregs (dict): a map from register names to Register objects
            valregs (dict): a map from register names to Register objects
            valreg (bool): if False the method ignores valregs and does not
                add regs for bits in the edge_map image that don't appear in valregs

        Returns:
            set(Register): the set of regs to add to self

        Raises:
            DAGCircuitError: if the wiremap fragments, or duplicates exist
        """
        # FIXME: some mixing of objects and strings here are awkward (due to
        # self.qregs/self.cregs still keying on string.
        add_regs = set()
        reg_frag_chk = {}
        for v in keyregs.values():
            reg_frag_chk[v] = {j: False for j in range(len(v))}
        for k in edge_map.keys():
            if k[0].name in keyregs:
                reg_frag_chk[k[0]][k[1]] = True
        for k, v in reg_frag_chk.items():
            s = set(v.values())
            if len(s) == 2:
                raise DAGCircuitError("edge_map fragments reg %s" % k)
            elif s == set([False]):
                if k in self.qregs.values() or k in self.cregs.values():
                    raise DAGCircuitError("unmapped duplicate reg %s" % k)
                else:
                    # Add registers that appear only in keyregs
                    add_regs.add(k)
            else:
                if valreg:
                    # If mapping to a register not in valregs, add it.
                    # (k,0) exists in edge_map because edge_map doesn't
                    # fragment k
                    if not edge_map[(k, 0)][0].name in valregs:
                        size = max(map(lambda x: x[1],
                                       filter(lambda x: x[0] == edge_map[(k, 0)][0],
                                              edge_map.values())))
                        qreg = QuantumRegister(size + 1, edge_map[(k, 0)][0].name)
                        add_regs.add(qreg)
        return add_regs
def _check_edgemap_registers(self, edge_map, keyregs, valregs, valreg=True):
        """Check that wiremap neither fragments nor leaves duplicate registers.

        1. There are no fragmented registers. A register in keyregs
        is fragmented if not all of its (qu)bits are renamed by edge_map.
        2. There are no duplicate registers. A register is duplicate if
        it appears in both self and keyregs but not in edge_map.

        Args:
            edge_map (dict): map from (reg,idx) in keyregs to (reg,idx) in valregs
            keyregs (dict): a map from register names to Register objects
            valregs (dict): a map from register names to Register objects
            valreg (bool): if False the method ignores valregs and does not
                add regs for bits in the edge_map image that don't appear in valregs

        Returns:
            set(Register): the set of regs to add to self

        Raises:
            DAGCircuitError: if the wiremap fragments, or duplicates exist
        """
        # FIXME: some mixing of objects and strings here are awkward (due to
        # self.qregs/self.cregs still keying on string.
        add_regs = set()
        reg_frag_chk = {}
        for v in keyregs.values():
            reg_frag_chk[v] = {j: False for j in range(len(v))}
        for k in edge_map.keys():
            if k[0].name in keyregs:
                reg_frag_chk[k[0]][k[1]] = True
        for k, v in reg_frag_chk.items():
            s = set(v.values())
            if len(s) == 2:
                raise DAGCircuitError("edge_map fragments reg %s" % k)
            elif s == set([False]):
                if k in self.qregs.values() or k in self.cregs.values():
                    raise DAGCircuitError("unmapped duplicate reg %s" % k)
                else:
                    # Add registers that appear only in keyregs
                    add_regs.add(k)
            else:
                if valreg:
                    # If mapping to a register not in valregs, add it.
                    # (k,0) exists in edge_map because edge_map doesn't
                    # fragment k
                    if not edge_map[(k, 0)][0].name in valregs:
                        size = max(map(lambda x: x[1],
                                       filter(lambda x: x[0] == edge_map[(k, 0)][0],
                                              edge_map.values())))
                        qreg = QuantumRegister(size + 1, edge_map[(k, 0)][0].name)
                        add_regs.add(qreg)
        return add_regs
Check that wiremap neither fragments nor leaves duplicate registers.

        1. There are no fragmented registers. A register in keyregs
        is fragmented if not all of its (qu)bits are renamed by edge_map.
        2. There are no duplicate registers. A register is duplicate if
        it appears in both self and keyregs but not in edge_map.

        Args:
            edge_map (dict): map from (reg,idx) in keyregs to (reg,idx) in valregs
            keyregs (dict): a map from register names to Register objects
            valregs (dict): a map from register names to Register objects
            valreg (bool): if False the method ignores valregs and does not
                add regs for bits in the edge_map image that don't appear in valregs

        Returns:
            set(Register): the set of regs to add to self

        Raises:
            DAGCircuitError: if the wiremap fragments, or duplicates exist