Enum Tribool

pub enum Tribool {
    True,
    False,
    Indeterminate,
}

Three-state Boolean logic

Variants

True

Truth value

False

False value

Indeterminate

Unknown/Indeterminate value

Implementations

impl Tribool

pub const fn boolean(value: bool) -> Tribool

Construct a new non-indeterminate Tribool from a regular boolean value

pub const fn is_true(self) -> bool

Returns true only if self is True

Example

assert!(Tribool::True.is_true())

pub const fn is_false(self) -> bool

Returns true only if self is False

Example

assert!(Tribool::False.is_false())

pub const fn is_indeterminate(self) -> bool

Returns true only if self is Indeterminate

Example

assert!(Tribool::Indeterminate.is_indeterminate())

pub const fn equals(self, rhs: Tribool) -> Tribool

Checks for equality of two Tribools, returning Indeterminate if either are indeterminate.

Example

assert!(Tribool::True.equals(Tribool::True).is_true());
assert!(Tribool::True.equals(Tribool::False).is_false());
assert!(Tribool::Indeterminate.equals(Tribool::False).is_indeterminate())

pub const fn not_equals(self, rhs: Tribool) -> Tribool

Checks for inequality of two Tribools, returning Indeterminate if either are indeterminate.

Example

assert!(Tribool::True.not_equals(Tribool::True).is_false());
assert!(Tribool::True.not_equals(Tribool::False).is_true());
assert!(Tribool::Indeterminate.not_equals(Tribool::False).is_indeterminate())

pub const fn kleene_implication(self, b: Tribool) -> Tribool

Material implication using Kleene Logic.

This is equivalent to NOT(A) OR B.

pub fn lukasiewicz_implication(self, b: Tribool) -> Tribool

Material implication using Łukasiewicz Logic

The Łukasiewicz Ł3 has the same tables for AND, OR, and NOT as the Kleene logic used elsewhere, but differs in its definition of implication in that “unknown implies unknown” is true.

For more information, see the Wikipedia page and the section on Łukasiewicz Logic

pub const fn and(self, rhs: Tribool) -> Tribool

Logical conjunction

pub const fn or(self, rhs: Tribool) -> Tribool

Logical disjunction

pub const fn xor(self, rhs: Tribool) -> Tribool

Logical exclusive disjunction

pub const fn negate(self) -> Tribool

Logical negation

pub const fn compare(self, rhs: Tribool) -> Option<Ordering>

Compares two Tribools similarly to a bool, where true is greater than false

Indeterminate values cannot be compared to order and therefore return None

Trait Implementations

impl<'a, 'b> BitAnd<&'a Tribool> for &'b Tribool

type Output = <Tribool as BitAnd>::Output

The resulting type after applying the & operator.

fn bitand(self, other: &'a Tribool) -> <Tribool as BitAnd<Tribool>>::Output

Performs the & operation.

impl<'a, 'b> BitAnd<&'a Tribool> for &'b bool

type Output = <bool as BitAnd<Tribool>>::Output

The resulting type after applying the & operator.

fn bitand(self, other: &'a Tribool) -> <bool as BitAnd<Tribool>>::Output

Performs the & operation.

impl<'a> BitAnd<&'a Tribool> for Tribool

type Output = <Tribool as BitAnd>::Output

The resulting type after applying the & operator.

fn bitand(self, other: &'a Tribool) -> <Tribool as BitAnd<Tribool>>::Output

Performs the & operation.

impl<'a> BitAnd<&'a Tribool> for bool

type Output = <bool as BitAnd<Tribool>>::Output

The resulting type after applying the & operator.

fn bitand(self, other: &'a Tribool) -> <bool as BitAnd<Tribool>>::Output

Performs the & operation.

impl<'a, 'b> BitAnd<&'a bool> for &'b Tribool

type Output = <Tribool as BitAnd<bool>>::Output

The resulting type after applying the & operator.

fn bitand(self, other: &'a bool) -> <Tribool as BitAnd<bool>>::Output

Performs the & operation.

impl<'a> BitAnd<&'a bool> for Tribool

type Output = <Tribool as BitAnd<bool>>::Output

The resulting type after applying the & operator.

fn bitand(self, other: &'a bool) -> <Tribool as BitAnd<bool>>::Output

Performs the & operation.

impl<B: Into<Tribool>> BitAnd<B> for Tribool

type Output = Tribool

The resulting type after applying the & operator.

fn bitand(self, rhs: B) -> Tribool

Performs the & operation.

impl<'a> BitAnd<Tribool> for &'a Tribool

type Output = <Tribool as BitAnd>::Output

The resulting type after applying the & operator.

fn bitand(self, other: Tribool) -> <Tribool as BitAnd<Tribool>>::Output

Performs the & operation.

impl<'a> BitAnd<Tribool> for &'a bool

type Output = <bool as BitAnd<Tribool>>::Output

The resulting type after applying the & operator.

fn bitand(self, other: Tribool) -> <bool as BitAnd<Tribool>>::Output

Performs the & operation.

impl BitAnd<Tribool> for bool

type Output = Tribool

The resulting type after applying the & operator.

fn bitand(self, rhs: Tribool) -> Tribool

Performs the & operation.

impl<'a> BitAnd<bool> for &'a Tribool

type Output = <Tribool as BitAnd<bool>>::Output

The resulting type after applying the & operator.

fn bitand(self, other: bool) -> <Tribool as BitAnd<bool>>::Output

Performs the & operation.

impl<B: Into<Tribool>> BitAndAssign<B> for Tribool

fn bitand_assign(&mut self, rhs: B)

Performs the &= operation.

impl BitAndAssign<Tribool> for bool

fn bitand_assign(&mut self, rhs: Tribool)

Performs the &= operation.

impl<'a, 'b> BitOr<&'a Tribool> for &'b Tribool

type Output = <Tribool as BitOr>::Output

The resulting type after applying the | operator.

fn bitor(self, other: &'a Tribool) -> <Tribool as BitOr<Tribool>>::Output

Performs the | operation.

impl<'a, 'b> BitOr<&'a Tribool> for &'b bool

type Output = <bool as BitOr<Tribool>>::Output

The resulting type after applying the | operator.

fn bitor(self, other: &'a Tribool) -> <bool as BitOr<Tribool>>::Output

Performs the | operation.

impl<'a> BitOr<&'a Tribool> for Tribool

type Output = <Tribool as BitOr>::Output

The resulting type after applying the | operator.

fn bitor(self, other: &'a Tribool) -> <Tribool as BitOr<Tribool>>::Output

Performs the | operation.

impl<'a> BitOr<&'a Tribool> for bool

type Output = <bool as BitOr<Tribool>>::Output

The resulting type after applying the | operator.

fn bitor(self, other: &'a Tribool) -> <bool as BitOr<Tribool>>::Output

Performs the | operation.

impl<'a, 'b> BitOr<&'a bool> for &'b Tribool

type Output = <Tribool as BitOr<bool>>::Output

The resulting type after applying the | operator.

fn bitor(self, other: &'a bool) -> <Tribool as BitOr<bool>>::Output

Performs the | operation.

impl<'a> BitOr<&'a bool> for Tribool

type Output = <Tribool as BitOr<bool>>::Output

The resulting type after applying the | operator.

fn bitor(self, other: &'a bool) -> <Tribool as BitOr<bool>>::Output

Performs the | operation.

impl<B: Into<Tribool>> BitOr<B> for Tribool

type Output = Tribool

The resulting type after applying the | operator.

fn bitor(self, rhs: B) -> Tribool

Performs the | operation.

impl<'a> BitOr<Tribool> for &'a Tribool

type Output = <Tribool as BitOr>::Output

The resulting type after applying the | operator.

fn bitor(self, other: Tribool) -> <Tribool as BitOr<Tribool>>::Output

Performs the | operation.

impl<'a> BitOr<Tribool> for &'a bool

type Output = <bool as BitOr<Tribool>>::Output

The resulting type after applying the | operator.

fn bitor(self, other: Tribool) -> <bool as BitOr<Tribool>>::Output

Performs the | operation.

impl BitOr<Tribool> for bool

type Output = Tribool

The resulting type after applying the | operator.

fn bitor(self, rhs: Tribool) -> Tribool

Performs the | operation.

impl<'a> BitOr<bool> for &'a Tribool

type Output = <Tribool as BitOr<bool>>::Output

The resulting type after applying the | operator.

fn bitor(self, other: bool) -> <Tribool as BitOr<bool>>::Output

Performs the | operation.

impl<B: Into<Tribool>> BitOrAssign<B> for Tribool

fn bitor_assign(&mut self, rhs: B)

Performs the |= operation.

impl BitOrAssign<Tribool> for bool

fn bitor_assign(&mut self, rhs: Tribool)

Performs the |= operation.

impl<'a, 'b> BitXor<&'a Tribool> for &'b Tribool

type Output = <Tribool as BitXor>::Output

The resulting type after applying the ^ operator.

fn bitxor(self, other: &'a Tribool) -> <Tribool as BitXor<Tribool>>::Output

Performs the ^ operation.

impl<'a, 'b> BitXor<&'a Tribool> for &'b bool

type Output = <bool as BitXor<Tribool>>::Output

The resulting type after applying the ^ operator.

fn bitxor(self, other: &'a Tribool) -> <bool as BitXor<Tribool>>::Output

Performs the ^ operation.

impl<'a> BitXor<&'a Tribool> for Tribool

type Output = <Tribool as BitXor>::Output

The resulting type after applying the ^ operator.

fn bitxor(self, other: &'a Tribool) -> <Tribool as BitXor<Tribool>>::Output

Performs the ^ operation.

impl<'a> BitXor<&'a Tribool> for bool

type Output = <bool as BitXor<Tribool>>::Output

The resulting type after applying the ^ operator.

fn bitxor(self, other: &'a Tribool) -> <bool as BitXor<Tribool>>::Output

Performs the ^ operation.

impl<'a, 'b> BitXor<&'a bool> for &'b Tribool

type Output = <Tribool as BitXor<bool>>::Output

The resulting type after applying the ^ operator.

fn bitxor(self, other: &'a bool) -> <Tribool as BitXor<bool>>::Output

Performs the ^ operation.

impl<'a> BitXor<&'a bool> for Tribool

type Output = <Tribool as BitXor<bool>>::Output

The resulting type after applying the ^ operator.

fn bitxor(self, other: &'a bool) -> <Tribool as BitXor<bool>>::Output

Performs the ^ operation.

impl<B: Into<Tribool>> BitXor<B> for Tribool

type Output = Tribool

The resulting type after applying the ^ operator.

fn bitxor(self, rhs: B) -> Tribool

Performs the ^ operation.

impl<'a> BitXor<Tribool> for &'a Tribool

type Output = <Tribool as BitXor>::Output

The resulting type after applying the ^ operator.

fn bitxor(self, other: Tribool) -> <Tribool as BitXor<Tribool>>::Output

Performs the ^ operation.

impl<'a> BitXor<Tribool> for &'a bool

type Output = <bool as BitXor<Tribool>>::Output

The resulting type after applying the ^ operator.

fn bitxor(self, other: Tribool) -> <bool as BitXor<Tribool>>::Output

Performs the ^ operation.

impl BitXor<Tribool> for bool

type Output = Tribool

The resulting type after applying the ^ operator.

fn bitxor(self, rhs: Tribool) -> Tribool

Performs the ^ operation.

impl<'a> BitXor<bool> for &'a Tribool

type Output = <Tribool as BitXor<bool>>::Output

The resulting type after applying the ^ operator.

fn bitxor(self, other: bool) -> <Tribool as BitXor<bool>>::Output

Performs the ^ operation.

impl<B: Into<Tribool>> BitXorAssign<B> for Tribool

fn bitxor_assign(&mut self, rhs: B)

Performs the ^= operation.

impl BitXorAssign<Tribool> for bool

fn bitxor_assign(&mut self, rhs: Tribool)

Performs the ^= operation.

impl Clone for Tribool

fn clone(&self) -> Tribool

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Tribool

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Tribool

fn default() -> Tribool

Returns the “default value” for a type.

impl Display for Tribool

fn fmt(&self, f: &mut Formatter<'_>) -> FmtResult

Formats the value using the given formatter.

impl From<Result<Tribool, IndeterminateError>> for Tribool

fn from(value: Result<Tribool, IndeterminateError>) -> Self

Converts to this type from the input type.

impl From<bool> for Tribool

fn from(value: bool) -> Tribool

Converts to this type from the input type.

impl FromStr for Tribool

type Err = ()

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Tribool, ()>

Parses a string s to return a value of this type.

impl Hash for Tribool

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<'a> Not for &'a Tribool

type Output = <Tribool as Not>::Output

The resulting type after applying the ! operator.

fn not(self) -> <Tribool as Not>::Output

Performs the unary ! operation.

impl Not for Tribool

type Output = Tribool

The resulting type after applying the ! operator.

fn not(self) -> Tribool

Performs the unary ! operation.

impl<B: Into<Tribool> + Copy> PartialEq<B> for Tribool

fn eq(&self, rhs: &B) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, rhs: &B) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq<Tribool> for bool

fn eq(&self, rhs: &Tribool) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, rhs: &Tribool) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<B: Into<Tribool> + Copy> PartialOrd<B> for Tribool

fn partial_cmp(&self, rhs: &B) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, rhs: &B) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, rhs: &B) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, rhs: &B) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, rhs: &B) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl TryFrom<Tribool> for bool

type Error = IndeterminateError

The type returned in the event of a conversion error.

fn try_from(value: Tribool) -> Result<Self, Self::Error>

Performs the conversion.

impl Copy for Tribool