High-performance typed signals for frequent emissions
npm install ferrsignTyped event emitter optimized for hot paths.
Signal/event library with separate classes for 0-3 arguments: Ferrsign0, Ferrsign1, Ferrsign2, Ferrsign3.
Performance on old devices (iPad Pro 1st gen, iOS 13, etc.) in frame loops.
A unified emit(...args) API would require:
- Array allocation on every call
- Spread operator when invoking callbacks
At 60fps with multiple signals per frame, this creates GC pressure and microstutters. Separate classes with explicit emit(a, b) calls avoid both.
typescript
import { Ferrsign0, Ferrsign1, Ferrsign2 } from "ferrsign";const onTick = new Ferrsign1();
const onClick = new Ferrsign2();
const onComplete = new Ferrsign0();
onTick.on((dt) => { / dt: number / });
onClick.on((x, y) => { / x: number, y: number / });
onComplete.once(() => { / ... / });
// In loop
onTick.emit(deltaTime);
onClick.emit(pointerX, pointerY);
onComplete.emit();
`API
All classes share the same interface:
-
— subscribe
- once(callback) — subscribe, auto-unsubscribe after first emit
- off(callback) — unsubscribe
- emit(...) — notify subscribers (argument count matches class)Read-only views
For exposing signals without emit access:
`typescript
import { Ferrsign1, FerrsignView1 } from "ferrsign";class Player {
private readonly _onDamage = new Ferrsign1();
get onDamage(): FerrsignView1 {
return this._onDamage;
}
}
const player = new Player();
player.onDamage.on((amount) => { / ... / }); // ✓
player.onDamage.emit(10); // ✗ Error — no emit on view
`Available views:
, FerrsignView1, FerrsignView2, FerrsignView3.Limitations
- Max 3 arguments. If you need more, use an object:
`typescript
const onResize = new Ferrsign1<{ width: number; height: number }>();
``Subscribing/unsubscribing during emit is handled correctly:
- New subscriptions are deferred until emit completes
- Removals mark slots for cleanup, no skipped/double calls