Struct Dual 

pub struct Dual<A>(pub A);

A newtype wrapper that reverses the order of a Semigroup’s operation.

append(Dual(a), Dual(b)) is equivalent to Dual(append(b, a)).

If the inner type is a Monoid, Dual is also a Monoid with the same identity element.

Examples

use fp_library::{
	functions::*,
	types::Dual,
};

let x = Dual("ab".to_string());
let y = Dual("cd".to_string());
assert_eq!(append(x, y), Dual("cdab".to_string()));

Tuple Fields

0: A

The wrapped value.

Trait Implementations

impl<A: Clone> Clone for Dual<A>

fn clone(&self) -> Dual<A>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<A: Debug> Debug for Dual<A>

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

Formats the value using the given formatter.

impl<A: Default> Default for Dual<A>

fn default() -> Dual<A>

Returns the “default value” for a type.

impl<A: Hash> Hash for Dual<A>

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: Monoid> Monoid for Dual<A>

Type Parameters

• A: The monoid type.

fn empty() -> Self

Returns Dual(empty()).

Type Signature

forall A. Monoid A => () -> Dual A

Returns

The identity element wrapped in Dual.

Examples

use fp_library::{
	functions::*,
	types::Dual,
};

assert_eq!(empty::<Dual<String>>(), Dual(String::new()));

impl<A: Ord> Ord for Dual<A>

fn cmp(&self, other: &Dual<A>) -> Ordering

This method returns an Ordering between self and other.

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

where Self: Sized,

Compares and returns the maximum of two values.

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

where Self: Sized,

Compares and returns the minimum of two values.

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

where Self: Sized,

Restrict a value to a certain interval.

impl<A: PartialEq> PartialEq for Dual<A>

fn eq(&self, other: &Dual<A>) -> 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<A: PartialOrd> PartialOrd for Dual<A>

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

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

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

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

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

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

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

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

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

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

impl<A: Semigroup> Semigroup for Dual<A>

Type Parameters

• A: The semigroup type.

fn append(a: Self, b: Self) -> Self

Combines two values in reverse order.

append(Dual(a), Dual(b)) computes Dual(append(b, a)).

Type Signature

forall A. Semigroup A => (Dual A, Dual A) -> Dual A

Parameters

• a: The first dual value.
• b: The second dual value.

Returns

The reversed combination wrapped in Dual.

Examples

use fp_library::{
	functions::*,
	types::Dual,
};

assert_eq!(append(Dual("ab".to_string()), Dual("cd".to_string())), Dual("cdab".to_string()));

impl<A: Copy> Copy for Dual<A>

impl<A: Eq> Eq for Dual<A>

impl<A> StructuralPartialEq for Dual<A>