Struct varisat::Var

#[repr(transparent)]
pub struct Var {
    index: u32,
}

A boolean variable.

A boolean value is represented by an index. Internally these are 0-based, i.e. the first variable has the index 0. For user IO a 1-based index is used, to allow denoting negated variables using negative integers. This convention is also used in the DIMACS CNF format.

Creating a variable with an index larger than Var::max_var().index() is unsupported. This might panic or be interpreted as a different variable.

Fields

index: u32

Methods

impl Var

pub fn from_dimacs(number: isize) -> Var

Creates a variable from a 1-based index as used in the DIMCAS CNF encoding.

The parameter must be positive and may not represent a variable past Var::max_var().

pub fn from_index(index: usize) -> Var

Creates a variable from a 0-based index.

The index may not represent a variable past Var::max_var().

pub fn to_dimacs(self) -> isize

The 1-based index representing this variable in the DIMACS CNF encoding.

pub const fn index(self) -> usize

The 0-based index representing this variable.

pub const fn max_var() -> Var

The variable with largest index that is supported.

This is less than the backing integer type supports. This enables storing a variable index and additional bits (as in Lit) or sentinel values in a single word.

pub const fn max_count() -> usize

Largest number of variables supported.

This is exactly Var::max_var().index() + 1.

pub fn lit(self, polarity: bool) -> Lit

Creates a literal from this var and a bool that is true when the literal is positive.

Shortcut for Lit::from_var(var, polarity).

pub fn positive(self) -> Lit

Creates a positive literal from this var.

Shortcut for Lit::positive(var).

pub fn negative(self) -> Lit

Creates a negative literal from this var.

Shortcut for Lit::negative(var).

Trait Implementations

impl Copy for Var

impl Ord for Var

fn cmp(&self, other: &Var) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

🔬 This is a nightly-only experimental API. (clamp)

Restrict a value to a certain interval.

impl Clone for Var

fn clone(&self) -> Var

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Var

Uses the 1-based DIMACS CNF encoding.

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

Formats the value using the given formatter.

impl PartialEq<Var> for Var

fn eq(&self, other: &Var) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Var) -> bool

This method tests for !=.

impl From<Var> for Lit

fn from(var: Var) -> Lit

Performs the conversion.

impl PartialOrd<Var> for Var

fn partial_cmp(&self, other: &Var) -> Option<Ordering>

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

fn lt(&self, other: &Var) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Var) -> bool

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

fn gt(&self, other: &Var) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Var) -> bool

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

impl Hash for Var

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

Feeds this value into the given [Hasher].

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

Feeds a slice of this type into the given [Hasher].

impl Eq for Var

fn assert_receiver_is_total_eq(&self)

impl Display for Var

Uses the 1-based DIMACS CNF encoding.

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

Formats the value using the given formatter.