Library-logger-child

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

Interface

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

input

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

output

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

Explanation

Detailed rules explaining key parameters and behaviors

• This API delegates to the wrapped 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 ..
• Sink type, minimum level, timestamp behavior, and any existing sink wrappers remain the same because only the derived target changes.
• Broader composition helpers remain hidden behind the narrower facade after rewrapping; use to_logger() if later code needs them.

How to Use

Here are some specific examples provided.

When Need Hierarchical Target Naming In A Library API

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

let worker = default_library_logger()
  .with_target("plugin")
  .child("worker")

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

When Build Scoped Facades Step By Step

When deeper target composition should stay readable:

let client = LibraryLogger::new(console_sink(), target="sdk")
  .child("http")
  .child("client")

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

And the target derivation does not rebuild or reset the wrapped logger pipeline.

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 target naming.

2. Composition uses . as the separator between parent and child segments.

3. Use with_target(...) instead when the new target should replace the current target rather than extend it.