Source code for algebraixlib.algebras.properties

"""Accessors for the properties of a generic `MathObject` that redirect to the appropriate algebra.

The accessors here check what algebra a given `MathObject` belongs to, then call the property
function of this algebra.
"""

# Copyright Algebraix Data Corporation 2015 - 2017
#
# This file is part of algebraixlib <http://github.com/AlgebraixData/algebraixlib>.
#
# algebraixlib is free software: you can redistribute it and/or modify it under the terms of version
# 3 of the GNU Lesser General Public License as published by the Free Software Foundation.
#
# algebraixlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
# even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License along with algebraixlib.
# If not, see <http://www.gnu.org/licenses/>.
# --------------------------------------------------------------------------------------------------
import algebraixlib.algebras.clans as _clans
import algebraixlib.algebras.couplets as _couplets
import algebraixlib.algebras.multiclans as _multiclans
import algebraixlib.algebras.relations as _relations
import algebraixlib.mathobjects as _mo
import algebraixlib.undef as _undef

from ..cache_status import CacheStatus


# --------------------------------------------------------------------------------------------------

[docs]def is_functional(mo: _mo.MathObject, _checked: bool=True) -> bool: r"""Return whether ``mo`` is :term:`functional` or `Undef()` if not applicable. Is implemented for :term:`relation`\s, :term:`clan`\s, :term:`multiclan`\s and :term:`set`\s of (sets of ...) clans. Is also defined (but not yet implemented) for any combination of sets or :term:`multiset`\s of relations. """ # pylint: disable=too-many-return-statements if _checked: if not isinstance(mo, _mo.MathObject): return _undef.make_or_raise_undef() # Check cache status. if mo.cached_functional == CacheStatus.IS: return True if mo.cached_functional == CacheStatus.IS_NOT: return False if mo.cached_functional == CacheStatus.N_A: return _undef.make_or_raise_undef(2) # Check type (functional is only defined on Sets and Multisets) and algebra memberships. if not mo.is_set and not mo.is_multiset: mo.cache_functional(CacheStatus.N_A) return _undef.make_or_raise_undef(2) if _relations.is_member(mo): return _relations.is_functional(mo, _checked=False) if _clans.is_member(mo): return _clans.is_functional(mo, _checked=False) if _multiclans.is_member(mo): return _multiclans.is_functional(mo, _checked=False) # Check higher (not yet defined) algebras. functional = _is_powerset_property(mo, _clans.get_ground_set(), is_functional) if functional is not _undef.Undef(): mo.cache_functional(CacheStatus.from_bool(functional)) return functional # Nothing applied: 'functional' is not defined. mo.cache_functional(CacheStatus.N_A) return _undef.make_or_raise_undef(2)
[docs]def is_right_functional(mo: _mo.MathObject, _checked: bool=True) -> bool: r"""Return whether ``mo`` is :term:`right-functional` or `Undef()` if not applicable. Is implemented for :term:`relation`\s, :term:`clan`\s, :term:`multiclan`\s and :term:`set`\s of (sets of ...) clans. Is also defined (but not yet implemented) for any combination of sets or :term:`multiset`\s of relations. """ # pylint: disable=too-many-return-statements if _checked: if not isinstance(mo, _mo.MathObject): return _undef.make_or_raise_undef() # Check cache status. if mo.cached_right_functional == CacheStatus.IS: return True if mo.cached_right_functional == CacheStatus.IS_NOT: return False if mo.cached_right_functional == CacheStatus.N_A: return _undef.make_or_raise_undef(2) # Check type (right-functional is only defined on Sets and Multisets) and algebra memberships. if not mo.is_set and not mo.is_multiset: mo.cache_right_functional(CacheStatus.N_A) return _undef.make_or_raise_undef(2) if _relations.is_member(mo): return _relations.is_right_functional(mo, _checked=False) if _clans.is_member(mo): return _clans.is_right_functional(mo, _checked=False) if _multiclans.is_member(mo): return _multiclans.is_right_functional(mo, _checked=False) # Check higher (not yet defined) algebras. right_functional = _is_powerset_property(mo, _clans.get_ground_set(), is_right_functional) if right_functional is not _undef.Undef(): mo.cache_right_functional(CacheStatus.from_bool(right_functional)) return right_functional # Nothing applied: 'right-functional' is not defined. mo.cache_right_functional(CacheStatus.N_A) return _undef.make_or_raise_undef(2)
[docs]def is_bijective(mo: _mo.MathObject, _checked: bool=True) -> bool: r"""Return whether ``mo`` is :term:`bijective` or `Undef()` if not applicable. Is implemented for :term:`relation`\s, :term:`clan`\s, :term:`multiclan`\s and :term:`set`\s of (sets of ...) clans. Is also defined (but not yet implemented) for any combination of sets or :term:`multiset`\s of relations. """ if _checked: if not isinstance(mo, _mo.MathObject): return _undef.make_or_raise_undef() # is_functional and is_right_functional are (un)defined for the same constructs, so the order # of evaluation is not important. functional = is_functional(mo, _checked=False) if functional is _undef.Undef() or not functional: return functional right_functional = is_right_functional(mo, _checked=False) if right_functional is _undef.Undef() or not right_functional: return right_functional return True
[docs]def is_reflexive(mo: _mo.MathObject, _checked: bool=True) -> bool: r"""Return whether ``mo`` is :term:`reflexive` or `Undef()` if not applicable. Is implemented for :term:`couplet`\s, :term:`relation`\s, :term:`clan`\s, :term:`multiclan`\s and :term:`set`\s of (sets of ...) clans. Is also defined (but not yet implemented) for any combination of sets or :term:`multiset`\s of relations. """ # pylint: disable=too-many-return-statements if _checked: if not isinstance(mo, _mo.MathObject): return _undef.make_or_raise_undef() # Check cache status. if mo.cached_reflexive == CacheStatus.IS: return True if mo.cached_reflexive == CacheStatus.IS_NOT: return False if mo.cached_reflexive == CacheStatus.N_A: return _undef.make_or_raise_undef(2) # Check types and algebra memberships. if _couplets.is_member(mo): return _couplets.is_reflexive(mo, _checked=False) if not mo.is_set and not mo.is_multiset: mo.cache_reflexive(CacheStatus.N_A) return _undef.make_or_raise_undef(2) if _relations.is_member(mo): return _relations.is_reflexive(mo, _checked=False) if _clans.is_member(mo): return _clans.is_reflexive(mo, _checked=False) if _multiclans.is_member(mo): return _multiclans.is_reflexive(mo, _checked=False) # Check higher (not yet defined) algebras. reflexive = _is_powerset_property(mo, _clans.get_ground_set(), is_reflexive) if reflexive is not _undef.Undef(): mo.cache_reflexive(CacheStatus.from_bool(reflexive)) return reflexive # Nothing applied: 'reflexive' is not defined. mo.cache_reflexive(CacheStatus.N_A) return _undef.make_or_raise_undef(2)
[docs]def is_symmetric(mo: _mo.MathObject, _checked: bool=True) -> bool: r"""Return whether ``mo`` is :term:`symmetric` or `Undef()` if not applicable. Is implemented for :term:`relation`\s, :term:`clan`\s, :term:`multiclan`\s and :term:`set`\s of (sets of ...) clans. Is also defined (but not yet implemented) for any combination of sets or :term:`multiset`\s of relations. """ # pylint: disable=too-many-return-statements if _checked: if not isinstance(mo, _mo.MathObject): return _undef.make_or_raise_undef() # Check cache status. if mo.cached_symmetric == CacheStatus.IS: return True if mo.cached_symmetric == CacheStatus.IS_NOT: return False if mo.cached_symmetric == CacheStatus.N_A: return _undef.make_or_raise_undef(2) # Check type (symmetric is only defined on Sets and Multisets) and algebra memberships. if not mo.is_set and not mo.is_multiset: mo.cache_symmetric(CacheStatus.N_A) return _undef.make_or_raise_undef(2) if _relations.is_member(mo): return _relations.is_symmetric(mo, _checked=False) if _clans.is_member(mo): return _clans.is_symmetric(mo, _checked=False) if _multiclans.is_member(mo): return _multiclans.is_symmetric(mo, _checked=False) # Check higher (not yet defined) algebras. symmetric = _is_powerset_property(mo, _relations.get_ground_set(), is_symmetric) if symmetric is not _undef.Undef(): mo.cache_symmetric(CacheStatus.from_bool(symmetric)) return symmetric # Nothing applied: 'symmetric' is not defined. mo.cache_symmetric(CacheStatus.N_A) return _undef.make_or_raise_undef(2)
[docs]def is_transitive(mo: _mo.MathObject, _checked: bool=True) -> bool: r"""Return whether ``mo`` is :term:`transitive` or `Undef()` if not applicable. Is implemented for :term:`relation`\s, :term:`clan`\s, :term:`multiclan`\s and :term:`set`\s of (sets of ...) clans. Is also defined (but not yet implemented) for any combination of sets or :term:`multiset`\s of relations. """ # pylint: disable=too-many-return-statements if _checked: if not isinstance(mo, _mo.MathObject): return _undef.make_or_raise_undef() # Check cache status. if mo.cached_transitive == CacheStatus.IS: return True if mo.cached_transitive == CacheStatus.IS_NOT: return False if mo.cached_transitive == CacheStatus.N_A: return _undef.make_or_raise_undef(2) # Check type (transitive is only defined on Sets and Multisets) and algebra memberships. if not mo.is_set and not mo.is_multiset: mo.cache_transitive(CacheStatus.N_A) return _undef.make_or_raise_undef(2) if _relations.is_member(mo): return _relations.is_transitive(mo, _checked=False) if _clans.is_member(mo): return _clans.is_transitive(mo, _checked=False) if _multiclans.is_member(mo): return _multiclans.is_transitive(mo, _checked=False) # Check higher (not yet defined) algebras. transitive = _is_powerset_property(mo, _relations.get_ground_set(), is_transitive) if transitive is not _undef.Undef(): mo.cache_transitive(CacheStatus.from_bool(transitive)) return transitive # Nothing applied: 'transitive' is not defined. mo.cache_transitive(CacheStatus.N_A) return _undef.make_or_raise_undef(2)
[docs]def is_equivalence_relation(mo: _mo.MathObject, _checked: bool=True) -> bool: r"""Return whether ``mo`` is an :term:`equivalence relation` or `Undef()` if not applicable. Is implemented for :term:`relation`\s, :term:`clan`\s, :term:`multiclan`\s and :term:`set`\s of (sets of ...) clans. Is also defined (but not yet implemented) for any combination of sets or :term:`multiset`\s of relations. """ if _checked: if not isinstance(mo, _mo.MathObject): return _undef.make_or_raise_undef() # is_reflexive is the only one that is defined for couplets, so it must be evaluated last or it # may result in erroneous `False` returns. symmetric = is_symmetric(mo, _checked=False) if symmetric is _undef.Undef() or not symmetric: return symmetric transitive = is_transitive(mo, _checked=False) if transitive is _undef.Undef() or not transitive: return transitive reflexive = is_reflexive(mo, _checked=False) if reflexive is _undef.Undef() or not reflexive: return reflexive return True
[docs]def is_regular(mo: _mo.MathObject, _checked: bool=True) -> bool: r"""Return whether ``mo`` is :term:`regular` or `Undef()` if not applicable. Is implemented for :term:`clan`\s, :term:`multiclan`\s and :term:`set`\s of (sets of ...) clans. Is also defined (but not yet implemented) for any combination of sets or :term:`multiset`\s of clans. """ # pylint: disable=too-many-return-statements if _checked: if not isinstance(mo, _mo.MathObject): return _undef.make_or_raise_undef() # Check cache status. if mo.cached_regular == CacheStatus.IS: return True if mo.cached_regular == CacheStatus.IS_NOT: return False if mo.cached_regular == CacheStatus.N_A: return _undef.make_or_raise_undef(2) # Check type (regular is only defined on Sets and Multisets) and algebra memberships. if not mo.is_set and not mo.is_multiset: mo.cache_regular(CacheStatus.N_A) return _undef.make_or_raise_undef(2) if _clans.is_member(mo): return _clans.is_regular(mo, _checked=False) if _multiclans.is_member(mo): return _multiclans.is_regular(mo, _checked=False) # Check higher (not yet defined) algebras. if mo.get_ground_set().get_powerset_level(_clans.get_ground_set()) > 0: mo_iter = iter(mo) elem1 = next(mo_iter) if not is_regular(elem1): mo.cache_regular(CacheStatus.IS_NOT) return False elem1_lefts = elem1.get_lefts() regular = all( is_regular(elem, _checked=False) and elem.get_lefts() == elem1_lefts for elem in mo_iter) mo.cache_regular(CacheStatus.from_bool(regular)) return mo.cached_is_regular # Nothing applied: 'regular' is not defined. mo.cache_regular(CacheStatus.N_A) return _undef.make_or_raise_undef(2)
[docs]def is_right_regular(mo: _mo.MathObject, _checked: bool=True) -> bool: r"""Return whether ``mo`` is :term:`right-regular` or `Undef()` if not applicable. Is implemented for :term:`clan`\s, :term:`multiclan`\s and :term:`set`\s of (sets of ...) clans. Is also defined (but not yet implemented) for any combination of sets or :term:`multiset`\s of clans. """ # pylint: disable=too-many-return-statements if _checked: if not isinstance(mo, _mo.MathObject): return _undef.make_or_raise_undef() # Check cache status. if mo.cached_right_regular == CacheStatus.IS: return True if mo.cached_right_regular == CacheStatus.IS_NOT: return False if mo.cached_right_regular == CacheStatus.N_A: return _undef.make_or_raise_undef(2) # Check type (right-regular is only defined on Sets and Multisets) and algebra memberships. if not mo.is_set and not mo.is_multiset: mo.cache_right_regular(CacheStatus.N_A) return _undef.make_or_raise_undef(2) if _clans.is_member(mo): return _clans.is_right_regular(mo, _checked=False) if _multiclans.is_member(mo): return _multiclans.is_right_regular(mo, _checked=False) # Check higher (not yet defined) algebras. if mo.get_ground_set().get_powerset_level(_clans.get_ground_set()) > 0: mo_iter = iter(mo) elem1 = next(mo_iter) if not is_right_regular(elem1): mo.cache_right_regular(CacheStatus.IS_NOT) return False elem1_rights = elem1.get_rights() right_regular = all( is_right_regular(elem, _checked=False) and elem.get_rights() == elem1_rights for elem in mo_iter) mo.cache_right_regular(CacheStatus.from_bool(right_regular)) return mo.cached_is_right_regular # Nothing applied: 'right-regular' is not defined. mo.cache_right_regular(CacheStatus.N_A) return _undef.make_or_raise_undef(2)
# -------------------------------------------------------------------------------------------------- def _is_powerset_property(mo: _mo.MathObject, ground_set, method) -> bool: """Return ``True`` if ``method`` returns ``True`` for all members of ``mo`` and ``mo`` is an element of an n-th power set of ``ground_set``. :param mo: The `MathObject` on which to operate. Must be a :term:`set`. :param ground_set: The :term:`ground set` of which the set ``mo`` should be part of (at the n-th :term:`power set` level). :param method: A property function (must return ``True``, ``False`` or `Undef()`) that should be run on all elements of ``mo``. It must be a function in this module. :return: ``True`` if this instance is element of an n-th power set of ``ground_set`` and all set elements return ``True`` for ``method``, ``False`` if it is an element of an n-th power set but any element returned ``False`` for ``method``, or `Undef()` if it isn't an element of an n-th power set. """ if mo.get_ground_set().get_powerset_level(ground_set) > 0: for element in mo: result = method(element) if result is _undef.Undef() or not result: return result return True return _undef.Undef()