Source code for beartype._conf.confcls

#!/usr/bin/env python3
# --------------------( LICENSE                            )--------------------
# Copyright (c) 2014-2023 Beartype authors.
# See "LICENSE" for further details.

'''
Beartype **configuration class hierarchy** (i.e., public dataclasses enabling
users to configure :mod:`beartype` with optional runtime behaviours).

Most of the public attributes defined by this private submodule are explicitly
exported to external users in our top-level :mod:`beartype.__init__` submodule.
This private submodule is *not* intended for direct importation by downstream
callers.
'''

# ....................{ TODO                               }....................
#FIXME: [DOCOS] Document all newly defined configuration parameters in our
#reST-formatted docos, please -- including:
#* "claw_is_pep526".
#* "coerce_decorator_exception_to_warning_category".

# ....................{ IMPORTS                            }....................
from beartype.roar import (
    BeartypeConfParamException,
)
from beartype.roar._roarwarn import (
    _BeartypeConfReduceDecoratorExceptionToWarningDefault)
from beartype.typing import (
    TYPE_CHECKING,
    Dict,
    Optional,
)
from beartype._cave._cavemap import NoneTypeOr
from beartype._conf.confenum import BeartypeStrategy
from beartype._conf._confget import get_is_color
from beartype._data.hint.datahinttyping import (
    BoolTristateUnpassable,
    TypeWarning,
)
from beartype._data.func.datafuncarg import ARG_VALUE_UNPASSED
from beartype._util.cls.utilclstest import is_type_subclass
from threading import Lock

# ....................{ CLASSES                            }....................
[docs]class BeartypeConf(object): ''' **Beartype configuration** (i.e., self-caching dataclass encapsulating all flags, options, settings, and other metadata configuring each type-checking operation performed by :mod:`beartype` -- including each decoration of a callable or class by the :func:`beartype.beartype` decorator). Attributes ---------- _claw_is_pep526 : bool :data:`True` only if type-checking **annotated variable assignments** (i.e., :pep:`526`-compliant assignments to local, global, class, and instance variables annotated by type hints) when importing modules under import hooks published by the :mod:`beartype.claw` subpackage. See also the :meth:`__new__` method docstring. _conf_args : tuple Efficiently hashable tuple of *all* parameters (in arbitrary order) with which this configuration was originally instantiated. _conf_kwargs : Dict[str, object] **Beartype configuration keyword dictionary** (i.e., dictionary mapping from the names of all keyword parameters accepted by the :meth:`__new__` method to the corresponding values of those parameters in this configuration). _is_color : Optional[bool] Tri-state boolean governing how and whether beartype colours **type-checking violations** (i.e., :class:`beartype.roar.BeartypeCallHintViolation` exceptions) with POSIX-compliant ANSI escape sequences for readability. Specifically, if this boolean is: * :data:`False`, beartype *never* colours type-checking violations raised by callables configured with this configuration. * :data:`True`, beartype *always* colours type-checking violations raised by callables configured with this configuration. * :data:`None`, beartype conditionally colours type-checking violations raised by callables configured with this configuration only when standard output is attached to an interactive terminal. _is_debug : bool :data:`True` only if debugging :mod:`beartype`. See also the :meth:`__new__` method docstring. _is_pep484_tower : bool :data:`True` only if enabling support for the :pep:`484`-compliant implicit numeric tower. See also the :meth:`__new__` method docstring. _is_warning_cls_on_decorator_exception_set : bool :data:`True` only if the caller explicitly passed the :attr:`_warning_cls_on_decorator_exception` parameter. See also the :meth:`__new__` method docstring. _strategy : BeartypeStrategy **Type-checking strategy** (i.e., :class:`BeartypeStrategy` enumeration member) with which to implement all type-checks in the wrapper function dynamically generated by the :func:`beartype.beartype` decorator for the decorated callable. _warning_cls_on_decorator_exception : Optional[TypeWarning] Configuration parameter governing whether the :func:`beartype.beartype` decorator reduces otherwise fatal exceptions raised at decoration time to equivalent non-fatal warnings of this warning category. See also the :meth:`__new__` method docstring. ''' # ..................{ CLASS VARIABLES }.................. #!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! # CAUTION: Synchronize this slots list with the implementations of: # * The __new__() dunder method. # * The __eq__() dunder method. # * The __hash__() dunder method. # * The __repr__() dunder method. # CAUTION: Subclasses declaring uniquely subclass-specific instance # variables *MUST* additionally slot those variables. Subclasses violating # this constraint will be usable but unslotted, which defeats our purposes. #!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! # Slot all instance variables defined on this object to minimize the time # complexity of both reading and writing variables across frequently called # cache dunder methods. Slotting has been shown to reduce read and write # costs by approximately ~10%, which is non-trivial. __slots__ = ( '_claw_is_pep526', '_conf_args', '_conf_kwargs', '_is_color', '_is_debug', '_is_pep484_tower', '_is_warning_cls_on_decorator_exception_set', '_strategy', '_warning_cls_on_decorator_exception', ) # Squelch false negatives from mypy. This is absurd. This is mypy. See: # https://github.com/python/mypy/issues/5941 if TYPE_CHECKING: _claw_is_pep526: bool _conf_args: tuple _conf_kwargs: Dict[str, object] _is_color: Optional[bool] _is_debug: bool _is_pep484_tower: bool _is_warning_cls_on_decorator_exception_set: bool _strategy: BeartypeStrategy _warning_cls_on_decorator_exception: Optional[TypeWarning] # ..................{ INSTANTIATORS }.................. # Note that this __new__() dunder method implements the superset of the # functionality typically implemented by the __init__() dunder method. Due # to Python instantiation semantics, the __init__() dunder method is # intentionally left undefined. Why? Because Python unconditionally invokes # __init__() if defined, even when the initialization performed by that # __init__() has already been performed for the cached instance returned by # __new__(). In short, __init__() and __new__() are largely mutually # exclusive; one typically defines one or the other but *NOT* both. def __new__( cls, # Optional keyword-only parameters. *, #FIXME: Uncomment us when implementing O(n) type-checking, please. # check_time_max_multiplier: Union[int, None] = 1000, claw_is_pep526: bool = True, is_color: BoolTristateUnpassable = ARG_VALUE_UNPASSED, is_debug: bool = False, is_pep484_tower: bool = False, strategy: BeartypeStrategy = BeartypeStrategy.O1, warning_cls_on_decorator_exception: Optional[TypeWarning] = ( _BeartypeConfReduceDecoratorExceptionToWarningDefault), ) -> 'BeartypeConf': ''' Instantiate this configuration if needed (i.e., if *no* prior configuration with these same parameters was previously instantiated) *or* reuse that previously instantiated configuration otherwise. This dunder methods guarantees beartype configurations to be memoized: .. code-block:: python >>> from beartype import BeartypeConf >>> BeartypeConf() is BeartypeConf() True This memoization is *not* merely an optimization. The :func:`beartype.beartype` decorator internally memoizes the private closure it creates and returns on the basis of this configuration, which *must* thus also be memoized. Parameters ---------- check_time_max_multiplier : Union[int, None] = 1000 **Deadline multiplier** (i.e., positive integer instructing :mod:`beartype` to prematurely halt the current type-check when the total running time of the active Python interpreter exceeds this integer multiplied by the running time consumed by both the current type-check and all prior type-checks *and* the caller also passed a non-default ``strategy``) *or* ``None`` if :mod:`beartype` should never prematurely halt runtime type-checks. Increase this quantity to type-check more container items at a cost of decreasing application responsiveness. Likewise, decrease this quantity to increase application responsiveness at a cost of type-checking fewer container items. Ignored when ``strategy`` is :attr:`BeartypeStrategy.O1`, as that strategy is already effectively instantaneous; imposing deadlines and thus bureaucratic bookkeeping on that strategy would only reduce its efficiency for no good reason, which is a bad reason. Defaults to 1000, in which case a maximum of %0.1 of the total runtime of the active Python process will be devoted to performing non-constant :mod:`beartype` type-checks over container items. This default has been carefully tuned to strike a reasonable balance between runtime type-check coverage and application responsiveness, typically enabling smaller containers to be fully type-checked without noticeably impacting codebase performance. *Theory time.* Let: * ``T`` be the total time this interpreter has been running. * ``b`` be the total time :mod:`beartype` has spent type-checking in this interpreter. Clearly, ``b <= T``. Generally, ``b <<<<<<< T`` (i.e., type-checks consume much less time than the total time consumed by the process). However, it's all too easy to exhibit worst-case behaviour of ``b ~= T`` (i.e., type-checks consume most of the total time). How? By passing the :func:`beartype.door.is_bearable` tester an absurdly large nested container subject to the non-default ``strategy`` of :attr:`BeartypeStrategy.On`. This deadline multiplier mitigates that worst-case behaviour. Specifically, :mod:`beartype` will prematurely halt any iterative type-check across a container when this constraint is triggered: .. code-block:: python b * check_time_max_multiplier >= T claw_is_pep526 : bool, optional :data:`True` only if implicitly type-checking **annotated variable assignments** (i.e., :pep:`526`-compliant assignments to local, global, class, and instance variables annotated by type hints) when importing modules under import hooks published by the :mod:`beartype.claw` subpackage by injecting calls to the :func:`beartype.door.die_if_unbearable` function immediately *after* those assignments in those modules. Enabling this boolean: * Effectively augments :mod:`beartype` into a full-blown **hybrid runtime-static type-checker** (i.e., performing both standard runtime type-checking *and* non-standard static type-checking at runtime). * Adds negligible runtime overhead to all annotated variable assignments in all modules imported under those import hooks. Although the *individual* cost of this overhead for any given assignment is negligible, the *aggregate* cost across all such assignments could be non-negligible in worst-case use cases. Ideally, this boolean should only be disabled for a small subset of performance-sensitive modules *after* profiling those modules to suffer performance regressions under import hooks published by the :mod:`beartype.claw` subpackage. Defaults to :data:`True`. is_color : BoolTristateUnpassable Tri-state boolean governing how and whether beartype colours **type-checking violations** (i.e., :class:`beartype.roar.BeartypeCallHintViolation` exceptions) with POSIX-compliant ANSI escape sequences for readability. Specifically, if this boolean is: * :data:`False`, beartype *never* colours type-checking violations raised by callables configured with this configuration. * :data:`True`, beartype *always* colours type-checking violations raised by callables configured with this configuration. * :data:`None`, beartype conditionally colours type-checking violations raised by callables configured with this configuration only when standard output is attached to an interactive terminal. The ``${BEARTYPE_IS_COLOR}`` environment variable globally overrides *all* attempts by *all* callers to explicitly pass this parameter, enabling end users to enforce a global colour policy across their full app stack. If ``${BEARTYPE_IS_COLOR}`` is set to a different value than that of this parameter, this constructor emits a non-fatal :class:`.BeartypeConfShellVarWarning` warning informing the caller of this configuration conflict. To avoid this conflict, open-source libraries are recommended to *not* pass this parameter; ideally, *only* end user apps should pass this parameter. Effectively defaults to :data:`None`. Technically, this parameter defaults to a private magic constant *not* intended to be passed by callers, enabling :mod:`beartype` to reliably detect whether the caller has explicitly passed this parameter or not. is_debug : bool, optional :data:`True` only if debugging :mod:`beartype`. Enabling this boolean: * Prints the definition (including both the signature and body) of each type-checking wrapper function dynamically generated by :mod:`beartype` to standard output. * Caches the body of each type-checking wrapper function dynamically generated by :mod:`beartype` with the standard :mod:`linecache` module, enabling these function bodies to be introspected at runtime *and* improving the readability of tracebacks whose call stacks contain one or more calls to these :func:`beartype.beartype`-decorated functions. * Appends to the declaration of each **hidden parameter** (i.e., whose name is prefixed by ``"__beartype_"`` and whose value is that of an external attribute internally referenced in the body of that function) the machine-readable representation of the initial value of that parameter, stripped of newlines and truncated to a hopefully sensible length. Since the :func:`beartype._util.text.utiltextrepr.represent_object` function called to do so is shockingly slow, these substrings are conditionally embedded in the returned signature *only* when enabling this boolean. Defaults to :data:`False`. is_pep484_tower : bool, optional :data:`True` only if enabling support for the :pep:`484`-compliant **implicit numeric tower** (i.e., lossy conversion of integers to floating-point numbers as well as both integers and floating-point numbers to complex numbers). Specifically, enabling this instructs :mod:`beartype` to automatically expand: * All :class:`float` type hints to ``float | int``, thus implicitly accepting both integers and floating-point numbers for objects annotated as only accepting floating-point numbers. * All :class:`complex` type hints to ``complex | float | int``, thus implicitly accepting integers, floating-point, and complex numbers for objects annotated as only accepting complex numbers. Defaults to :data:`False` to minimize precision error introduced by lossy conversions from integers to floating-point numbers to complex numbers. Since most integers do *not* have exact representations as floating-point numbers, each conversion of an integer into a floating-point number typically introduces a small precision error that accumulates over multiple conversions and operations into a larger precision error. Enabling this improves the usability of public APIs at a cost of introducing precision errors. strategy : BeartypeStrategy, optional **Type-checking strategy** (i.e., :class:`BeartypeStrategy` enumeration member) with which to implement all type-checks in the wrapper function dynamically generated by the :func:`beartype.beartype` decorator for the decorated callable. Defaults to :attr: `BeartypeStrategy.O1`, the ``O(1)`` constant-time strategy. warning_cls_on_decorator_exception : Optional[TypeWarning] Configuration parameter governing whether the :func:`beartype.beartype` decorator reduces what would otherwise be fatal exceptions raised at decoration time to equivalent non-fatal warnings of the passed **warning category** (i.e., subclass of the standard :class:`Warning` class). Specifically, this parameter may be either: * :data:`None`, in which case the :func:`beartype.beartype` decorator raises fatal exceptions at decoration time. * A warning category, in which case the :func:`beartype.beartype` decorator reduces fatal exceptions to non-fatal warnings of this category at decoration time. Defaults to a private warning type *not* intended to be passed by callers, enabling :mod:`beartype` to reliably detect when the caller has *not* explicitly passed this parameter and respond accordingly by defaulting this parameter to a context-dependent value. Notably, if this parameter is *not* explicitly passed: * The :func:`beartype.beartype` decorator defaults this parameter to :data:`None`, thus raising decoration-time exceptions. * The :mod:`beartype.claw` API defaults this parameter to the public :class:`beartype.roar.BeartypeClawDecorWarning` warning category, thus reducing decoration-time exceptions to warnings of that category when performing import hooks. This default behaviour significantly increases the likelihood that import hooks installed by :mod:`beartype.claw` will successfully decorate the entirety of their target packages rather than prematurely halt with a single fatal exception at the first decoration issue. Returns ---------- BeartypeConf Beartype configuration memoized with these parameters. Raises ---------- BeartypeConfParamException If either: * ``is_color`` is *not* a tri-state boolean. * ``is_debug`` is *not* a boolean. * ``is_pep484_tower`` is *not* a boolean. * ``strategy`` is *not* a :class:`BeartypeStrategy` enumeration member. * ``warning_cls_on_decorator_exception`` is neither :data:`None` *nor* a **warning category** (i.e., :class:`Warning` subclass). BeartypeConfShellVarException If either: * The external ``${BEARTYPE_IS_COLOR}`` shell environment variable is set to an unrecognized string (i.e., neither ``"True"``, ``"False"``, nor ``"None"``). ''' #!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! # CAUTION: Synchronize this tuple with the similar "self._conf_kwargs" # dictionary defined below. #!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! # In a non-reentrant thread lock specific to beartype configurations... # # Note that this lock is potentially overkill and thus unnecessary. # Nonetheless, since the number of beartype configurations instantiated # over the lifetime of the average Python interpreter is small, since # non-reentrant thread locks are reasonably fast to enter, and since the # cost of race conditions is high, this lock does no real-world harm and # may actually do a great deal of real-world good. Safety first, all! with _beartype_conf_lock: # ..................{ CACHE }.................. # Validate and possibly override the "is_color" parameter by the # value of the ${BEARTYPE_IS_COLOR} environment variable (if set). is_color = get_is_color(is_color) # Efficiently hashable tuple of these parameters in arbitrary order. conf_args = ( claw_is_pep526, is_color, is_debug, is_pep484_tower, strategy, warning_cls_on_decorator_exception, ) # If this method has already instantiated a configuration with these # parameters, return that configuration for consistency and # efficiency. if conf_args in _beartype_conf_args_to_conf: return _beartype_conf_args_to_conf[conf_args] # ..................{ VALIDATE }.................. # Else, this method has yet to instantiate a configuration with # these parameters. In this case, do so below (and cache that # configuration). # # If "claw_is_pep526" is *NOT* a boolean, raise an exception. elif not isinstance(claw_is_pep526, bool): raise BeartypeConfParamException( f'Beartype configuration parameter "claw_is_pep526" ' f'value {repr(claw_is_pep526)} not boolean.' ) # Else, "claw_is_pep526" is a boolean. # # If "is_color" is *NOT* a tri-state boolean, raise an exception. elif not isinstance(is_color, NoneTypeOr[bool]): raise BeartypeConfParamException( f'Beartype configuration parameter "is_color" ' f'value {repr(is_color)} not tri-state boolean ' f'(i.e., "True", "False", or "None").' ) # Else, "is_color" is a tri-state boolean. # # If "is_debug" is *NOT* a boolean, raise an exception. elif not isinstance(is_debug, bool): raise BeartypeConfParamException( f'Beartype configuration parameter "is_debug" ' f'value {repr(is_debug)} not boolean.' ) # Else, "is_debug" is a boolean. # # If "is_pep484_tower" is *NOT* a boolean, raise an exception. elif not isinstance(is_pep484_tower, bool): raise BeartypeConfParamException( f'Beartype configuration parameter "is_pep484_tower" ' f'value {repr(is_debug)} not boolean.' ) # Else, "is_pep484_tower" is a boolean. # # If "strategy" is *NOT* an enumeration member, raise an exception. elif not isinstance(strategy, BeartypeStrategy): raise BeartypeConfParamException( f'Beartype configuration parameter "strategy" ' f'value {repr(strategy)} not ' f'"beartype.BeartypeStrategy" enumeration member.' ) # Else, "strategy" is an enumeration member. # # If "warning_cls_on_decorator_exception" is neither # "None" *NOR* a warning category, raise an exception. elif not ( warning_cls_on_decorator_exception is None or is_type_subclass(warning_cls_on_decorator_exception, Warning) ): raise BeartypeConfParamException( f'Beartype configuration parameter ' f'"warning_cls_on_decorator_exception" value ' f'{repr(warning_cls_on_decorator_exception)} ' f'neither "None" nor warning category ' f'(i.e., "Warning" subclass).' ) # Else, "warning_cls_on_decorator_exception" is either # "None" *OR* a warning category. # Instantiate a new configuration of this type. self = super().__new__(cls) # ..................{ DEFAULT }.................. # If the value of the "warning_cls_on_decorator_exception" parameter # is still the default private fake warning category established # above, then the caller failed to explicitly pass a valid value. In # this case... if ( warning_cls_on_decorator_exception is _BeartypeConfReduceDecoratorExceptionToWarningDefault ): # Note this fact for subsequent reference elsewhere (e.g., in # the "beartype.claw" subpackage). self._is_warning_cls_on_decorator_exception_set = False # Default this parameter to "None" for safety. Since this # default private fake warning category is *NOT* an actual # warning category intended for real-world use, this category # *MUST* be replaced with a sane default that is safely usable. warning_cls_on_decorator_exception = None # Else, the caller explicitly passed a valid value for this # parameter. In this case, preserve this value and note this fact. else: self._is_warning_cls_on_decorator_exception_set = True # ..................{ CLASSIFY }.................. # Classify all passed parameters with this configuration. self._claw_is_pep526 = claw_is_pep526 self._is_color = is_color self._is_debug = is_debug self._is_pep484_tower = is_pep484_tower self._warning_cls_on_decorator_exception = ( warning_cls_on_decorator_exception) self._strategy = strategy # Cache this configuration with all relevant dictionary singletons. _beartype_conf_args_to_conf[conf_args] = self # Store data structures encapsulating these passed parameters for # subsequent reuse. self._conf_args = conf_args self._conf_kwargs = dict( claw_is_pep526=claw_is_pep526, is_color=is_color, is_debug=is_debug, is_pep484_tower=is_pep484_tower, strategy=strategy, warning_cls_on_decorator_exception=( warning_cls_on_decorator_exception), ) # Assert that these two data structures encapsulate the same number # of configuration parameters (as a feeble safety check). assert len(self._conf_args) == len(self._conf_kwargs) # Return this configuration. return self # ..................{ PROPERTIES }.................. # Read-only public properties effectively prohibiting mutation of their # underlying private attributes. #FIXME: Publicly document this in our reST-formatted docos, please. @property def kwargs(self) -> Dict[str, object]: ''' **Beartype configuration keyword dictionary** (i.e., dictionary mapping from the names of all keyword parameters accepted by the :meth:`__new__` method to the corresponding values of those parameters in this configuration). This property can be used to permute new configurations from existing configurations, overriding only a small handful of parameters while preserving all other parameters as is: e.g., .. code-block:: python # Arbitrary input beartype configuration. conf = BeartypeConf(is_color=True) # Permuted output beartype configuration keyword dictionary. kwargs = conf.kwargs.copy() kwargs['is_debug'] = True # Output beartype configuration permuted from this input. debug_conf = BeartypeConf(**kwargs) See Also ---------- :meth:`__new__` Further details. ''' return self._conf_kwargs # ..................{ PROPERTIES ~ parameters }.................. # Read-only public properties with which this configuration was originally # instantiated (as keyword-only parameters). @property def claw_is_pep526(self) -> bool: ''' :data:`True` only if type-checking **annotated variable assignments** (i.e., :pep:`526`-compliant assignments to local, global, class, and instance variables annotated by type hints) when importing modules under import hooks published by the :mod:`beartype.claw` subpackage. See Also ---------- :meth:`__new__` Further details. ''' return self._claw_is_pep526 @property def is_color(self) -> Optional[bool]: ''' Tri-state boolean governing how and whether beartype colours **type-checking violations** (i.e., :class:`beartype.roar.BeartypeCallHintViolation` exceptions) with POSIX-compliant ANSI escape sequences for readability. Specifically, if this boolean is: * :data:`False`, beartype *never* colours type-checking violations raised by callables configured with this configuration. * :data:`True`, beartype *always* colours type-checking violations raised by callables configured with this configuration. * :data:`None`, beartype conditionally colours type-checking violations raised by callables configured with this configuration only when standard output is attached to an interactive terminal. ''' return self._is_color @property def is_debug(self) -> bool: ''' :data:`True` only if debugging :mod:`beartype`. See Also ---------- :meth:`__new__` Further details. ''' return self._is_debug @property def is_pep484_tower(self) -> bool: ''' :data:`True` only if enabling support for the :pep:`484`-compliant implicit numeric tower. See Also ---------- :meth:`__new__` Further details. ''' return self._is_pep484_tower @property def strategy(self) -> BeartypeStrategy: ''' **Type-checking strategy** (i.e., :class:`BeartypeStrategy` enumeration member) with which to implement all type-checks in the wrapper function dynamically generated by the :func:`beartype.beartype` decorator for the decorated callable. ''' return self._strategy @property def warning_cls_on_decorator_exception(self) -> ( Optional[TypeWarning]): ''' Configuration parameter governing whether the :func:`beartype.beartype` decorator reduces otherwise fatal exceptions raised at decoration time to equivalent non-fatal warnings of this warning category. See Also ---------- :meth:`__new__` Further details. ''' return self._warning_cls_on_decorator_exception # ..................{ DUNDERS }.................. def __eq__(self, other: object) -> bool: ''' **Beartype configuration equality comparator.** Parameters ---------- other : object Arbitrary object to be compared for equality against this configuration. Returns ---------- Union[bool, type(NotImplemented)] Either: * If this other object is also a beartype configuration, either: * If these configurations share the same settings, :data:`True`. * Else, :data:`False`. * Else, :data:`NotImplemented`. See Also ---------- :func:`_hash_beartype_conf` Further details. ''' # Return either... return ( # If this other object is also a beartype configuration, true only # if these configurations share the same settings; self._conf_args == other._conf_args if isinstance(other, BeartypeConf) else # Else, this other object is *NOT* also a beartype configuration. In # this case, the standard singleton informing Python that this # equality comparator fails to support this comparison. NotImplemented # type: ignore[return-value] ) def __hash__(self) -> int: ''' **Hash** (i.e., non-negative integer quasi-uniquely identifying this beartype configuration with respect to hashable container membership). Returns ---------- int Hash of this configuration. ''' #!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! # CAUTION: Synchronize this logic with BeartypeConf.__new__(). #!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! # Return the hash of a tuple containing these parameters in an # arbitrary (albeit well-defined) order. # # Note this has been profiled to be the optimal means of hashing object # attributes in Python, where "optimal" means: # * Optimally fast. CPython in particular optimizes the creation and # garbage collection of "small" tuples, where "small" is ill-defined # but almost certainly applies here. # * Optimally uniformly distributed, thus minimizing the likelihood of # expensive hash collisions. return hash(self._conf_args) def __repr__(self) -> str: ''' **Beartype configuration representation** (i.e., machine-readable string which, when dynamically evaluated as code, restores access to this exact configuration object). Returns ---------- str Representation of this configuration. ''' return ( f'{self.__class__.__name__}(' f'claw_is_pep526={repr(self._claw_is_pep526)}' f', is_color={repr(self._is_color)}' f', is_debug={repr(self._is_debug)}' f', is_pep484_tower={repr(self._is_pep484_tower)}' f', strategy={repr(self._strategy)}' f', warning_cls_on_decorator_exception={repr(self._warning_cls_on_decorator_exception)}' f')' )
# ....................{ PRIVATE ~ globals }.................... _beartype_conf_lock = Lock() ''' **Non-reentrant beartype configuration thread lock** (i.e., low-level thread locking mechanism implemented as a highly efficient C extension, defined as an global for non-reentrant reuse elsewhere as a context manager). ''' _beartype_conf_args_to_conf: Dict[tuple, BeartypeConf] = {} ''' Non-thread-safe **beartype configuration parameter cache** (i.e., dictionary mapping from the hash of each set of parameters accepted by a prior call of the :meth:`BeartypeConf.__new__` instantiator to the unique :class:`BeartypeConf` instance instantiated by that call). Caveats ---------- **This cache is non-thread-safe.** However, since this cache is only used as a memoization optimization, the only harmful consequences of a race condition between threads contending over this cache is a mildly inefficient (but otherwise harmless) repeated re-memoization of duplicate configurations. ''' # ....................{ GLOBALS }.................... # This global is intentionally defined *AFTER* all other attributes above, which # this global implicitly assumes to be defined. BEARTYPE_CONF_DEFAULT = BeartypeConf() ''' **Default beartype configuration** (i.e., :class:`BeartypeConf` class instantiated with *no* parameters and thus default parameters), globalized to trivially optimize external access to this configuration throughout this codebase. Note that this global is *not* publicized to end users, who can simply instantiate ``BeartypeConf()`` to obtain the same singleton. '''