# filterMapEffect

Effectfully maps each Fx output and emits only resulting `Some` values.

One mapper Effect runs per upstream value. `Some(c)` emits once, `None` emits
nothing, and failures join the output error channel. Sequential sources retain
order; the input Sink remains unchanged.

## Signatures

```ts
export declare const filterMapEffect: {
    <B, C, E3, R3>(f: (b: B) => Effect.Effect<Option.Option<C>, E3, R3>): <A, E, R, E2, R2>(push: Push<A, E, R, B, E2, R2>) => Push<A, E, R, C, E2 | E3, R2 | R3>;
    <A, E, R, B, E2, R2, C, E3, R3>(push: Push<A, E, R, B, E2, R2>, f: (b: B) => Effect.Effect<Option.Option<C>, E3, R3>): Push<A, E, R, C, E2 | E3, R2 | R3>;
};
```

## Why

This models service-backed lookup where absence is an ordinary filtered result
but operational failure must remain observable.

## Ownership and lifetime

Mapper effects are owned and interrupted by the output subscription. Their
services join `R2` and failures join `E2`; the combinator adds no independent
buffer or resource.

## Examples

```ts
import { Effect, Option } from "effect"
import * as Fx from "@typed/fx/Fx"
import * as Push from "@typed/fx/Push"
import * as Sink from "@typed/fx/Sink"

const push = Push.make(Sink.make(() => Effect.void, (_: string) => Effect.void), Fx.succeed("one"))
const ids = Push.filterMapEffect(push, (name) => Effect.succeed(name === "one" ? Option.some(1) : Option.none()))
```