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Library-logger-new

Create a LibraryLogger[S] from any sink implementation. This is the library-facing sync constructor when you want standard logging behavior but do not want to expose the full Logger[S] surface.

Interface

moonbit
pub fn[S] LibraryLogger::new(
  sink : S,
  min_level~ : Level = Level::Info,
  target~ : String = "",
) -> LibraryLogger[S] {

input

  • sink : S - Underlying sink value that should receive writes, such as console_sink() or a composed sink.
  • min_level : Level - Minimum enabled level. Messages below this threshold are ignored.
  • target : String - Default target attached to emitted records unless later overridden.

output

  • LibraryLogger[S] - Narrow library-facing wrapper over a newly created sync logger.

Explanation

Detailed rules explaining key parameters and behaviors

  • This API builds a regular Logger::new(...) internally and then wraps that same value as LibraryLogger.
  • The returned facade intentionally exposes a smaller method set than the full Logger[S] type.
  • The original sink type is still preserved in LibraryLogger[S].
  • This constructor does not add timestamps, filters, patches, or extra sink wrappers by itself; it only creates the base sync logger and narrows its public surface.
  • Call to_logger() if later code must recover the full sync logger surface.

How to Use

Here are some specific examples provided.

When Need A Narrower Library-facing Constructor

When a package should create a logger without exposing the full logger API:

moonbit
let logger = LibraryLogger::new(console_sink(), min_level=Level::Info, target="plugin")
logger.info("loaded")

In this example, the package creates a normal sync logger pipeline but publishes only the smaller facade type.

When Accept A Generic Sink But Keep Library Boundaries Small

When a library API wants typed sinks without exposing extra composition helpers:

moonbit
let logger = LibraryLogger::new(text_console_sink(text_formatter()), target="worker")

In this example, sink typing remains explicit while the consumer only sees the library facade.

When Need Full Logger Composition Later

When library-facing construction should still allow later access to broader sync composition helpers:

moonbit
let logger = LibraryLogger::new(console_sink(), target="lib")
let full = logger.to_logger().with_timestamp()

In this example, construction starts from the narrower facade, but the same underlying logger can still be recovered and extended later.

Error Case

e.g.:

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

  • If later code needs methods outside the facade, it must unwrap with to_logger().

  • If callers want additional wrappers such as timestamps, filters, patches, or queued/context sink layers immediately, they must apply those through the full Logger[S] surface or the dedicated facade helpers.

Notes

  1. This is the direct constructor counterpart to Logger::new(...) for library-oriented APIs.

  2. Prefer this when public package boundaries should stay narrower than Logger[S].

  3. Use Logger::new(...) directly when the full sync composition surface should remain public from the start.

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