Core Concepts

Atoms

Atoms are the basic building blocks of state. They hold a value and allow subscription to changes.

import { atom } from '@reaxium/core';

const count = atom(0);
console.log(count.get()); // 0
count.set(1);
console.log(count.get()); // 1

Key Features:

• Immutable Updates: Atoms notify listeners only when the value changes.
• Subscription Model: Listen to changes with subscribe.

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Computed Values

Computed values are derived from one or more atoms and update automatically when dependencies change.

import { atom, computed } from '@reaxium/core';

const firstName = atom('John');
const lastName = atom('Doe');
const fullName = computed(
  () => `${firstName.get()} ${lastName.get()}`,
  [firstName, lastName]
);

console.log(fullName.get()); // "John Doe"
firstName.set('Jane');
console.log(fullName.get()); // "Jane Doe"

Key Features:

• Automatic Updates: No manual re-calculation needed.
• Dependency Tracking: Only re-computes when dependencies change.

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Batching Updates

Group multiple state updates into a single notification cycle for performance.

import { atom, batch } from '@reaxium/core';

const a = atom(0);
const b = atom(0);

batch(() => {
  a.set(1);
  b.set(2);
});
// Listeners are notified only once