Flavored Booleans¶

For when different flavors of the truth matter.

final class pythonic_fp.booleans.flavored.FBool¶

Bases: SBool

Favored Booleans

When different flavors of the truth matter. Each FBool is an SBool subtype corresponding to a hashable flavor.

Warning

Combining FBool instances of different flavors with bitwise operators will result in a runtime ValueError exception.

static __new__(cls, witness: object, flavor: Hashable) → Self¶

new

Traditional singleton pattern but with a ClassVar dict to store the for truthy or falsy singleton for each hashable flavor.

param witness:: Determines truthiness of the FBool instance returned.
param flavor:: The flavor of FBool to created.
returns:: The truthy or falsy FBool instance of a particular flavor.

__init__(witness: object, flavor: Hashable) → None¶

initialize

Let the flavored boolean know its flavor.

param witness:: Determines truthiness of the FBool instance returned.
param flavor:: The flavor of FBool to created.
type flavor:: H: Hashable
returns:: The truthy or falsy FBool instance of a particular flavor.
raises ValueError:: If different flavors compared with bitwise operators.

__reduce__() → tuple[type[FBool], tuple[Hashable]]¶

reduce

Tell pickle and copy how to reconstruct the SBool singleton by calling SBool() rather than rebuilding the object directly.

reconstruction goes through __new__, so the flavor cache is consulted
unpickling returns the existing singleton of that flavor, or creates and caches it in a fresh interpreter
copy and deepcopy use the same protocol, so they return the singleton unchanged

returns:: The pair (SBool, ((self._flavor))), which pickle uses to rebuild the singleton.

Important

Without this, pickle would construct a duplicate SBool outside the instance dict, and is comparisons against it would silently fail.

__invert__() → FBool¶

bitwise invert operator

Inverts the value of an FBool.

returns:: The inverted value of the FBool.

__and__(other: int) → int¶

bitwise and operator

Overloading & to perform Boolean “and” if other is another FBool of the same flavor.

param other:: Any object derived from int.
returns:: Boolean “and” if other is an FBool of the same flavor, otherwise returns bitwise “and”.
raises:: ValueError if other is an FBool of a different flavor.

__or__(other: int) → int¶

bitwise or operator

Overloading | to perform Boolean “or” if other is another FBool of the same flavor.

param other:: Any object derived from int.
returns:: Boolean “or” if other is an FBool of the same flavor, otherwise returns bitwise “or”.
raises:: ValueError if other is an FBool of a different flavor.

__xor__(other: int) → int¶

bitwise xor operator

Overloading ^ to perform Boolean “xor” if other is another FBool of the same flavor.

param other:: Any object derived from int.
returns:: Boolean “xor” if other is an FBool of the same flavor, otherwise returns bitwise “or”.
raises:: ValueError if other is an FBool of a different flavor.

__repr__() → str¶

repr string

Create strings of the form

FBool(True, repr_flavor)
FBool(False, repr_flavor)

Where repr_flavor = repr(self.flavor())

returns:: A String to reproduce the flavored boolean.

__str__() → str¶

user string

Create strings of the form

FBool(True, str_flavor)
FBool(False, str_flavor)

Where str_flavor = str(self.flavor())

returns:: A String meaningful to an end user.

flavor() → Hashable¶

flavor

Get the flavor of the FBool, a hashable value.

returns:: The flavor of the FBool.

pythonic_fp.booleans.flavored.truthy(flavor: Hashable) → FBool¶

function truthy

Returns the truthy singleton FBool of a particular flavor.

param flavor:: Hashable value to determine which singleton flavor to return.
returns:: The truthy singleton of a particular flavor.

pythonic_fp.booleans.flavored.falsy(flavor: Hashable) → FBool¶

Function falsy

Returns the falsy singleton FBool of a particular flavor.

param flavor:: Hashable value to determine which singleton flavor to return.
returns:: The falsy singleton of a particular flavor.