Struct Sum 

pub struct Sum<T>(pub T);

Wrapper type for the addition monoid.

Sum<T> forms a monoid under addition (+), making it useful for accumulating numeric values, counting, or gradient accumulation in automatic differentiation.

Examples

use algebra_core::{Monoid, Semigroup, Sum};

let a = Sum(5);
let b = Sum(3);
let c = a.combine(&b);
assert_eq!(c, Sum(8));

assert_eq!(Sum::<i32>::empty(), Sum(0));

Use in Autodiff

Gradient accumulation in reverse-mode automatic differentiation is fundamentally Sum<f64>:

use algebra_core::{Semigroup, Sum};

let grad1 = Sum(0.5);
let grad2 = Sum(0.3);
let total_grad = grad1.combine(&grad2);
assert_eq!(total_grad.0, 0.8);

Tuple Fields

0: T

Trait Implementations

impl<T: Clone> Clone for Sum<T>

fn clone(&self) -> Sum<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for Sum<T>

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

Formats the value using the given formatter.

impl<T: Hash> Hash for Sum<T>

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<T: Add<Output = T> + Clone + Zero> Monoid for Sum<T>

fn empty() -> Self

The identity element.

fn concat<I>(iter: I) -> Self

where I: IntoIterator<Item = Self>,

Fold an iterator using combine, starting from empty.

impl<T: Ord> Ord for Sum<T>

fn cmp(&self, other: &Sum<T>) -> 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<T: PartialEq> PartialEq for Sum<T>

fn eq(&self, other: &Sum<T>) -> 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<T: PartialOrd> PartialOrd for Sum<T>

fn partial_cmp(&self, other: &Sum<T>) -> 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<T: Add<Output = T> + Clone> Semigroup for Sum<T>

fn combine(&self, other: &Self) -> Self

Combine two elements associatively.

fn combine_assign(&mut self, other: &Self)

In-place combine.

impl<T: Add<Output = T> + Clone + Zero> CommutativeMonoid for Sum<T>

impl<T: Copy> Copy for Sum<T>

impl<T: Eq> Eq for Sum<T>

impl<T> StructuralPartialEq for Sum<T>