BitLogger/docs/api/library-async-logger-child.md

name, group, category, update-time, description, key-word

name	group	category	update-time	description	key-word
library-async-logger-child	api	facade	20260613	Derive a child LibraryAsyncLogger facade by composing the current target with a child segment.	async library child public

Library-async-logger-child

Create a child LibraryAsyncLogger[S] by composing the current target with another target segment. This is the library-facing hierarchical naming helper for async targets such as sdk.cache or plugin.worker.io.

Interface

pub fn[S] LibraryAsyncLogger::child(
  self : LibraryAsyncLogger[S],
  target : String,
) -> LibraryAsyncLogger[S] {

input

• self : LibraryAsyncLogger[S] - Parent facade whose target should be extended.
• target : String - Child target segment or suffix.

output

• LibraryAsyncLogger[S] - New library-facing async facade whose target is the composed child path.

Explanation

Detailed rules explaining key parameters and behaviors

• This API delegates to the wrapped async logger's child(...) behavior and then re-wraps the result.
• If the parent target is empty, the child target becomes the full target.
• If the child target is empty, the parent target is preserved.
• If both are non-empty, they are joined with ..

How to Use

Here are some specific examples provided.

When Need Hierarchical Async Naming In A Library API

When a package wants stable namespace composition without exposing AsyncLogger[S]:

let worker = LibraryAsyncLogger::new(@bitlogger.console_sink())
  .with_target("plugin")
  .child("worker")

In this example, the final target becomes plugin.worker.

When Build Scoped Async Facades Step By Step

When deeper target composition should stay readable:

let client = LibraryAsyncLogger::new(@bitlogger.console_sink(), target="sdk")
  .child("http")
  .child("client")

In this example, the final facade emits under sdk.http.client.

Error Case

e.g.:

• If target is empty, the returned facade keeps the original parent target.

• If callers need complete replacement instead of composition, with_target(...) should be used instead.

Notes

1. This is the preferred library-facing API for hierarchical async target naming.

2. Composition changes the target only and does not rebuild the queue or sink.