PNCounter

Increment and decrement counter. Ideal for inventory, vote tallies.

A PNCounter (Positive-Negative Counter) supports both increments and decrements. Internally it uses two GCounters — one for increments, one for decrements. The value is increments - decrements.

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Usage

const stock = client.pncounter("pn:product-42-stock");

// Increment / decrement
stock.increment(10);
stock.decrement(3);

// Read
console.log(stock.value()); // number (can be negative)

// Subscribe
const unsub = stock.onChange(v => console.log("stock:", v));
unsub();

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API

Method	Description
increment(amount?: number)	Add amount (default 1, must be > 0)
decrement(amount?: number)	Subtract amount (default 1, must be > 0)
value()	Returns increments - decrements
onChange(fn)	Subscribe — returns unsubscribe function
stream()	Returns an Effect Stream<number> that emits on every change