# exhaustLatestMap

Maps each element to an inner Fx, running one now and retaining only the latest waiting value.

## Signatures

```ts
export declare const exhaustLatestMap: FlatMapLike;
```

## Why

`exhaustLatestMap` fits work that cannot overlap but must eventually reflect
the newest request. Unlike {@link exhaustMap }, it remembers one pending value;
unlike {@link concatMap }, it does not let a backlog grow.

## Admission, buffering, and cardinality

The first value while idle starts immediately. While that inner runs, each new
value replaces the single pending inner Effect; replaced values never run.
When the active inner completes, the latest pending inner starts. An admitted
inner may emit any number of values, in that inner's order.

## Ownership and lifetime

Source and admitted-inner failures are forwarded and both environments remain
typed. The required `Scope` owns every active inner fiber. Source completion
waits until the active and final pending inner finish; interruption closes the
Scope and runs inner finalizers. The one-slot pending buffer retains work, not
emitted output.

## Examples

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

const refreshes = Fx.mergeAll(
  Fx.at("v1", "0 millis"),
  Fx.at("v2", "5 millis"),
  Fx.at("v3", "10 millis")
)
const latestEventually = Fx.exhaustLatestMap(refreshes, (version) =>
  Fx.at(`indexed:${version}`, "20 millis")
)

Effect.runPromise(Effect.scoped(Fx.collectAll(latestEventually))).then(console.log)
// ["indexed:v1", "indexed:v3"]
```