import warnings
from typing import Dict, Final, Callable, Generator
from symmetria import Permutation
from symmetria.generators._validators import _check_degree_parameter, _check_algorithm_parameter
from symmetria.generators.algorithm._algorithms import (
_heap,
_zaks,
_lexicographic,
_steinhaus_johnson_trotter,
)
__all__ = ["generate", "permutation_generator"]
_SUPPORTED_ALGORITHMS: Final[Dict[str, Callable]] = {
"lexicographic": _lexicographic,
"heap": _heap,
"steinhaus-johnson-trotter": _steinhaus_johnson_trotter,
"zaks": _zaks,
}
[docs]
def generate(degree: int, algorithm: str = "lexicographic") -> Generator[Permutation, None, None]:
"""Generate all the permutations of the given degree based on the chosen algorithm.
:warning: This function will be deprecated in a future version. Use 'permutation_generator' instead.
The method generates all the permutations of the given degree using the specified algorithm.
:param degree: The degree of the permutations to be generated. Must be a non-zero positive integer.
:type degree: int
:param algorithm: The algorithm to use for generating permutations.
It must be one of: ``lexicographic``, ``heap``.
Default is ``lexicographic``.
:type algorithm: str, optional
:return: A generator yielding permutations.
:rtype: Generator["Permutation", None, None]
:raises ValueError: If the algorithm is not supported or the degree is invalid.
:examples:
>>> import symmetria
...
>>> permutations = symmetria.generate(degree=3, algorithm="lexicographic")
>>> for permutation in permutations:
... permutation
Permutation(1, 2, 3)
Permutation(1, 3, 2)
Permutation(2, 1, 3)
Permutation(2, 3, 1)
Permutation(3, 1, 2)
Permutation(3, 2, 1)
"""
warnings.warn(
"This function will be deprecated in a future version. Use 'permutation_generator' instead.",
PendingDeprecationWarning,
stacklevel=1,
)
_check_algorithm_parameter(value=algorithm, supported=list(_SUPPORTED_ALGORITHMS.keys()))
_check_degree_parameter(value=degree)
return _relevant_generator(algorithm=algorithm, degree=degree)
[docs]
def permutation_generator(degree: int, algorithm: str = "lexicographic") -> Generator[Permutation, None, None]:
"""Generate all the permutations of the given degree based on the chosen algorithm.
The method generates all the permutations of the given degree using the specified algorithm.
:param degree: The degree of the permutations to be generated. Must be a non-zero positive integer.
:type degree: int
:param algorithm: The algorithm to use for generating permutations.
It must be one of: ``lexicographic``, ``heap``.
Default is ``lexicographic``.
:type algorithm: str, optional
:return: A generator yielding permutations.
:rtype: Generator["Permutation", None, None]
:raises ValueError: If the algorithm is not supported or the degree is invalid.
:examples:
>>> from symmetria import permutation_generator
...
>>> permutations = permutation_generator(degree=3, algorithm="lexicographic")
>>> for permutation in permutations:
... permutation
Permutation(1, 2, 3)
Permutation(1, 3, 2)
Permutation(2, 1, 3)
Permutation(2, 3, 1)
Permutation(3, 1, 2)
Permutation(3, 2, 1)
"""
_check_algorithm_parameter(value=algorithm, supported=list(_SUPPORTED_ALGORITHMS.keys()))
_check_degree_parameter(value=degree)
return _relevant_generator(algorithm=algorithm, degree=degree)
def _relevant_generator(algorithm: str, degree: int) -> Generator[Permutation, None, None]:
"""Private method to pick the correct algorithm for generating permutations."""
if algorithm in _SUPPORTED_ALGORITHMS:
return _SUPPORTED_ALGORITHMS[algorithm](degree=degree)
raise ValueError(
f"The given algorithm ({algorithm}) is not supported. \n "
f"Here, a list of supported algorithm for generations of permutations {list(_SUPPORTED_ALGORITHMS.keys())}."
)
