# since

Drops `events` until `signal` emits, then forwards the rest.

## Signatures

```ts
export declare const since: {
    <B, E2, R2>(signal: Fx<B, E2, R2>): <A, E, R>(events: Fx<A, E, R>) => Fx<A, E | E2, R | R2>;
    <A, E, R, B, E2, R2>(events: Fx<A, E, R>, signal: Fx<B, E2, R2>): Fx<A, E | E2, R | R2>;
};
```

## Why

`since` uses one Fx as a start boundary for another. Events before the first signal are dropped;
after it arrives, remaining events emit in their original order. Signal values are not emitted.

## Ownership and lifetime

Event and signal runs share a child Scope. The signal observer fiber is forked but never joined:
a signal failure ends that fiber and is discarded rather than delivered to the event Sink, so it
does not stop events. Event completion closes the Scope; consumer interruption stops both runs.

## Examples

```ts
import { Fx } from "@typed/fx"

// This Effect succeeds with []; the failed signal neither opens the gate nor fails collection.
const program = Fx.collectAll(Fx.since(Fx.fromIterable([1, 2]), Fx.fail("signal failed")))
```