Enum sudoku_backend::ops::BoardDifficulty

pub enum BoardDifficulty {
    Easy,
    Medium,
    Hard,
}

The difficulties sudoku boards can come in.

Consult doc/sudoku.md

Variants

EasyMediumHard

Methods

impl BoardDifficulty

pub fn score(&self, solve_time: &Duration) -> Option<u64>

Calculate the score for a board according to doc/sudoku.md#scoring-formula

Negative duration is out of domain and will return None.

Examples

assert_eq!(BoardDifficulty::Easy.score(&Duration::seconds(120)), Some(55));
assert_eq!(BoardDifficulty::Hard.score(&Duration::seconds(250)), Some(126));

assert_eq!(BoardDifficulty::Medium.score(&Duration::seconds(-65)), None);

pub fn from_numeric(repr: u64) -> Option<BoardDifficulty>

Parse a numerical representation of the difficulty.

Guaranteed to validly round-trip through to_numeric().

Examples

assert_eq!(BoardDifficulty::from_numeric(1), Some(BoardDifficulty::Easy));
assert_eq!(BoardDifficulty::from_numeric(2), Some(BoardDifficulty::Medium));
assert_eq!(BoardDifficulty::from_numeric(3), Some(BoardDifficulty::Hard));

assert_eq!(BoardDifficulty::from_numeric(0), None);
assert_eq!(BoardDifficulty::from_numeric(4), None);
assert_eq!(BoardDifficulty::from_numeric(25), None);

pub fn to_numeric(&self) -> u64

Convert difficulty to a numeric repr

Guaranteed to validly round-trip through from_numeric().

Examples

assert_eq!(BoardDifficulty::Easy.to_numeric(), 1);
assert_eq!(BoardDifficulty::Medium.to_numeric(), 2);
assert_eq!(BoardDifficulty::Hard.to_numeric(), 3);

assert_eq!(BoardDifficulty::from_numeric(BoardDifficulty::Easy.to_numeric()),
           Some(BoardDifficulty::Easy));

pub fn additional_squares(&self) -> usize

How many more squares to compensate difficulty with.

A good approximation of Sudoku difficulty is square sparsity, so to make a board easier one can simply add more squares to the default unique solution.

Examples

assert_eq!(BoardDifficulty::Easy.additional_squares(), 22);
assert_eq!(BoardDifficulty::Medium.additional_squares(), 11);
assert_eq!(BoardDifficulty::Hard.additional_squares(), 0);

Trait Implementations

impl PartialEq<BoardDifficulty> for BoardDifficulty

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

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

#[must_use] fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl Clone for BoardDifficulty

fn clone(&self) -> BoardDifficulty

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for BoardDifficulty

impl Ord for BoardDifficulty

fn cmp(&self, other: &BoardDifficulty) -> 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.

impl Eq for BoardDifficulty

impl PartialOrd<BoardDifficulty> for BoardDifficulty

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

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

#[must_use] fn lt(&self, other: &Rhs) -> bool

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

#[must_use] fn le(&self, other: &Rhs) -> bool

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

#[must_use] fn gt(&self, other: &Rhs) -> bool

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

#[must_use] fn ge(&self, other: &Rhs) -> bool

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

impl Debug for BoardDifficulty

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

Formats the value using the given formatter.

impl Hash for BoardDifficulty

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,

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

impl Serialize for BoardDifficulty

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error> where     __S: Serializer,

Serialize this value into the given Serde serializer.

impl<'de> Deserialize<'de> for BoardDifficulty

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error> where     __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<'v> FromFormValue<'v> for BoardDifficulty

type Error = Option<String>

The associated error which can be returned from parsing. It is a good idea to have the return type be or contain an &'v str so that the unparseable string can be examined after a bad parse.

fn from_form_value(form_value: &'v RawStr) -> Result<Self, Self::Error>

Parses an instance of Self from an HTTP form field value or returns an Error if one cannot be parsed.

fn default() -> Option<Self>

Returns a default value to be used when the form field does not exist. If this returns None, then the field is required. Otherwise, this should return Some(default_value). The default implementation simply returns None.