Struct Extract

pub struct Extract<E, C> { /* private fields */ }

A comparator that extracts a sort key from a value.

Examples

use compare::{Compare, Extract};
use std::cmp::Ordering::Greater;

let a = [1, 2, 3];
let b = [4, 5];

let cmp = Extract::new(|s: &[i32]| s.len());
assert_eq!(cmp.compare(&a, &b), Greater);

Implementations

impl<E, K> Extract<E, Natural<K>>

where K: Ord,

pub fn new<T: ?Sized>(ext: E) -> Self

where E: Fn(&T) -> K,

Returns a comparator that extracts a sort key using ext and compares it according to its natural ordering.

impl<E, C> Extract<E, C>

pub fn with_cmp<T: ?Sized, K>(ext: E, cmp: C) -> Self

where E: Fn(&T) -> K, C: Compare<K>,

Returns a comparator that extracts a sort key using ext and compares it using cmp.

Trait Implementations

impl<E: Clone, C: Clone> Clone for Extract<E, C>

fn clone(&self) -> Extract<E, C>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<E, C, T: ?Sized, K> Compare<T> for Extract<E, C>

where E: Fn(&T) -> K, C: Compare<K>,

fn compare(&self, l: &T, r: &T) -> Ordering

Compares two values, returning Less, Equal, or Greater if l is less than, equal to, or greater than r, respectively.

fn compares_lt(&self, l: &T, r: &T) -> bool

Checks if l is less than r.

fn compares_le(&self, l: &T, r: &T) -> bool

Checks if l is less than or equal to r.

fn compares_ge(&self, l: &T, r: &T) -> bool

Checks if l is greater than or equal to r.

fn compares_gt(&self, l: &T, r: &T) -> bool

Checks if l is greater than r.

fn compares_eq(&self, l: &T, r: &T) -> bool

Checks if l is equal to r.

fn compares_ne(&self, l: &T, r: &T) -> bool

Checks if l is not equal to r.

fn borrowing(self) -> Borrowing<Self, L, R>

where Self: Sized,

Borrows the comparator’s parameters before comparing them.

fn rev(self) -> Rev<Self>

where Self: Sized,

Reverses the ordering of the comparator.

fn swap(self) -> Swap<Self>

where Self: Sized,

Swaps the comparator’s parameters, maintaining the underlying ordering.

fn then<D>(self, then: D) -> Then<Self, D>

where D: Compare<L, R>, Self: Sized,

Lexicographically combines the comparator with another.

impl<E: Debug, C: Debug> Debug for Extract<E, C>

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

Formats the value using the given formatter.

impl<E: Default, C: Default> Default for Extract<E, C>

fn default() -> Extract<E, C>

Returns the “default value” for a type.

impl<E: PartialEq, C: PartialEq> PartialEq for Extract<E, C>

fn eq(&self, other: &Extract<E, C>) -> bool

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

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

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

impl<E: Copy, C: Copy> Copy for Extract<E, C>

impl<E: Eq, C: Eq> Eq for Extract<E, C>

impl<E, C> StructuralPartialEq for Extract<E, C>