Source code for cirq.ops.gate_features

# Copyright 2018 The Cirq Developers
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# Licensed under the Apache License, Version 2.0 (the "License");
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#     https://www.apache.org/licenses/LICENSE-2.0
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"""Marker classes for indicating which additional features gates support.

For example: some gates are reversible, some have known matrices, etc.
"""

from typing import Iterable

import abc

from cirq.ops import op_tree, raw_types


[docs]class InterchangeableQubitsGate(metaclass=abc.ABCMeta): """Indicates operations should be equal under some qubit permutations."""
[docs] def qubit_index_to_equivalence_group_key(self, index: int) -> int: """Returns a key that differs between non-interchangeable qubits.""" return 0
[docs]class SingleQubitGate(raw_types.Gate, metaclass=abc.ABCMeta): """A gate that must be applied to exactly one qubit."""
[docs] def validate_args(self, qubits): if len(qubits) != 1: raise ValueError( 'Single-qubit gate applied to multiple qubits: {}({})'. format(self, qubits))
[docs] def on_each(self, targets: Iterable[raw_types.QubitId]) -> op_tree.OP_TREE: """Returns a list of operations apply this gate to each of the targets. Args: targets: The qubits to apply this gate to. Returns: Operations applying this gate to the target qubits. """ return [self.on(target) for target in targets]
[docs]class TwoQubitGate(raw_types.Gate, metaclass=abc.ABCMeta): """A gate that must be applied to exactly two qubits."""
[docs] def validate_args(self, qubits): if len(qubits) != 2: raise ValueError( 'Two-qubit gate not applied to two qubits: {}({})'. format(self, qubits))
[docs]class ThreeQubitGate(raw_types.Gate, metaclass=abc.ABCMeta): """A gate that must be applied to exactly three qubits."""
[docs] def validate_args(self, qubits): if len(qubits) != 3: raise ValueError( 'Three-qubit gate not applied to three qubits: {}({})'. format(self, qubits))