BitLogger/docs/api/library-async-logger-with-target.md

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

name	group	category	update-time	description	key-word
library-async-logger-with-target	api	facade	20260614	Replace the default target carried by a LibraryAsyncLogger facade while rewrapping the derived async logger state behind the same library-facing surface.	async library facade public

Library-async-logger-with-target

Replace the default target on a LibraryAsyncLogger[S]. This is the library-facing counterpart to AsyncLogger::with_target(...) when package code wants to retarget an async logger without exposing the full async logger API.

Interface

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

input

• self : LibraryAsyncLogger[S] - Base facade whose default target should be replaced.
• target : String - New default target namespace.

output

• LibraryAsyncLogger[S] - New library-facing async facade carrying the updated target.

Explanation

Detailed rules explaining key parameters and behaviors

• This API delegates to the wrapped async logger's with_target(...) behavior and then re-wraps the result as another LibraryAsyncLogger[S].
• The original facade is not mutated. The returned facade stores the replacement target while the source facade keeps its previous target.
• Timestamp behavior, enabled-level gating, sink type, queue state, async config, and failure/lifecycle state stay the same because only the default target field changes.
• This replaces the default target instead of composing it.
• Async state helpers remain hidden behind the narrower facade after rewrapping; use to_async_logger() if later code needs them.

How to Use

Here are some specific examples provided.

When Need A New Fixed Async Namespace Inside Library Code

When one facade should emit under a different async target namespace:

let logger = LibraryAsyncLogger::new(@bitlogger.console_sink())
  .with_target("sdk.http")

In this example, later async writes inherit sdk.http unless a call overrides the target directly.

When Reuse One Async Setup Across Library Subsystems

When multiple library-facing async loggers should share one queue policy:

let base = LibraryAsyncLogger::new(
  @bitlogger.console_sink(),
  config=AsyncLoggerConfig::new(max_pending=64),
)
let cache = base.with_target("cache")
let io = base.with_target("io")

In this example, one base facade becomes several target-specific async facades.

And each derived facade still wraps the same kind of queue-backed async logger state, differing only in the default target it carries.

The derived facade keeps the same timestamp and level-gating behavior as the source facade.

Error Case

e.g.:

• If target is empty, the returned logger remains valid and later records simply use an empty default target.

• If callers need hierarchical target composition rather than replacement, child(...) is the better API.

Notes

1. Use this API for replacement, not target-path composition.

2. It keeps the narrower LibraryAsyncLogger boundary intact.

3. Use child(...) when the new target should be combined with the current one instead of replacing it.