batch()

Runs fn while deferring type 1 (DATA) emissions until the outermost batch completes. Type 3 (STATE) DIRTY signals still propagate immediately so the graph knows what changed.

Signature

function batch<T>(fn: () => T): T

Parameters

Parameter	Type	Description
fn	() => T	Synchronous work that may call set() / emit() on many stores.

Returns

The return value of fn.

Basic Usage

import { state, derived, batch } from 'callbag-recharge';

const a = state(1);
const b = state(2);
const sum = derived([a, b], () => a.get() + b.get());
batch(() => {
    a.set(10);
    b.set(20);
  });
sum.get(); // 30

Options / Behavior Details

• Nesting: Inner batches increment depth; only the outermost finally drains deferred emissions.
• Derived/effects: Downstream nodes typically see one settled value per batch boundary.

See Also

• state
• derived