BitLogger/docs/api/logger-to-library-logger.md

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

name	group	category	update-time	description	key-word
logger-to-library-logger	api	facade	20260613	Convert a full sync logger into the narrower library-facing sync facade without rebuilding the underlying logger state.	logger library facade public

Logger-to-library-logger

Convert Logger[S] into LibraryLogger[S]. This keeps the same sink and logging behavior while projecting the value onto the smaller library-facing sync surface.

Interface

pub fn[S] Logger::to_library_logger(self : Logger[S]) -> LibraryLogger[S] {}

input

• self : Logger[S] - Full sync logger to project into the library facade.

output

• LibraryLogger[S] - Narrower library-facing wrapper over the same logger state.

Explanation

Detailed rules explaining key parameters and behaviors

• This conversion does not rebuild the sink or change the logger configuration.
• Target, min level, timestamp behavior, and sink wiring are preserved because the same underlying logger value is wrapped.
• The returned facade keeps library-oriented write APIs such as info(...), warn(...), and error(...).
• Broader sync composition helpers remain on the underlying Logger[S] and are intentionally hidden until to_logger() is used again.

How to Use

Here are some specific examples provided.

When Need To Return A Narrower Library Type

When internal setup uses the full logger API but the exposed result should stay smaller:

let logger = Logger::new(console_sink(), target="lib")
let public_logger = logger.to_library_logger()

In this example, public_logger keeps the same logging behavior but exposes the library facade.

When Need To Narrow Surface Without Resetting Logger Composition

When an already-shaped logger should be projected to a library boundary without losing its current wrappers:

let full = Logger::new(console_sink(), target="lib").with_timestamp()
let public_logger = full.to_library_logger()

In this example, the projection changes the exposed type only; it does not remove the existing timestamp behavior or other logger state.

Error Case

e.g.:

• If callers later need APIs outside the library facade, they must unwrap with to_logger().

• The conversion does not remove existing target or field bindings from the original logger.

• If callers later need composition helpers such as with_timestamp(...), with_filter(...), or with_patch(...), they must unwrap again with to_logger().

Notes

1. Use this when library boundaries should avoid exposing the full sync logger surface.

2. This is a projection API, not a copy or rebuild step.

3. Use build_library_logger(...) or parse_and_build_library_logger(...) when construction and narrowing should happen together from config.