Struct FirstSubject 

pub struct FirstSubject(pub Subject);

Newtype wrapper for “first wins” combination strategy.

When combining two FirstSubject instances, the first subject is returned and the second is discarded. This is useful for scenarios where you want to keep the initial subject and ignore subsequent ones.

Semigroup Laws

This satisfies associativity trivially: first(first(a, b), c) = first(a, first(b, c)) = a

Examples

use pattern_core::{Subject, Symbol, Combinable};
use std::collections::HashSet;

let s1 = Subject {
    identity: Symbol("alice".to_string()),
    labels: HashSet::new(),
    properties: Default::default(),
};

let s2 = Subject {
    identity: Symbol("bob".to_string()),
    labels: HashSet::new(),
    properties: Default::default(),
};

// First wins - s2 is discarded
let result = s1.combine(s2);
assert_eq!(result.identity.0, "alice");

Tuple Fields

0: Subject

Trait Implementations

impl Clone for FirstSubject

fn clone(&self) -> FirstSubject

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Combinable for FirstSubject

fn combine(self, _other: Self) -> Self

Combines two values associatively.

impl PartialEq for FirstSubject

fn eq(&self, other: &FirstSubject) -> 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 StructuralPartialEq for FirstSubject