Common Types

ComponentLogging

Module-scoped logging utilities for Julia built on top of the stdlib Logging. This package provides:

• A ComponentLogger with hierarchical rule keys to control log levels per component path, e.g. (:net, :http).
• Lightweight functions clog, clogenabled, clogf for emitting messages and checking if logging is enabled.
• Macros @clog, @clogf, @clogenabled that capture the caller module/source location for accurate provenance.
• Macro @forward_logger to generate module-local forwarding methods.
• A simple PlainLogger sink for pretty, colored output without timestamps/prefixes.

Typical usage:

using ComponentLogging

rules = Dict(
    :core => Info,
    :io => Warn,
    :net => Debug
)
clogger = ComponentLogger(rules; sink=PlainLogger())

clog(clogger, :core, Info, "something happened")

ComponentLogger(; sink=ConsoleLogger(Debug))
ComponentLogger(rules::AbstractDict; sink=ConsoleLogger(Debug))

A logger that delegates to an underlying sink (AbstractLogger) while applying component-based minimum level rules. Rules are defined on paths of symbols (NTuple{N,Symbol}). A lookup walks up the path and falls back to (:__default__,).

• sink: the underlying AbstractLogger that actually handles messages.
• rules: mapping from NTuple{N,Symbol} to LogLevel. The default entry ((DEFAULT_SYM,), Info) is created automatically when needed.

The effective minimum level is the minimum of all values in rules, cached in the min field for fast checks.

PlainLogger(; stream=Base.CoreLogging.closed_stream, min_level=Info)

A simple AbstractLogger implementation that prints messages without standard prefixes/timestamps, with minimal coloring by level.

• stream::IO: target stream; if closed, falls back to stderr.
• min_level::LogLevel: minimum enabled level for the sink.

Intended for tests, demos, or embedding in custom sinks.

set_log_level!(logger, group, lvl) -> ComponentLogger

Set or update the minimum level for a specific component group on logger. group may be a Symbol or a NTuple{N,Symbol} tuple; lvl can be LogLevel or Integer. If lvl is a Bool, it is treated as a simple switch: true sets the rule to Info and false sets it to LogLevel(1) (which disables the default clogenabled(logger, group) check). Updates the internal min cache appropriately.

with_min_level(f, logger, lvl)

Temporarily set logger.min to lvl while executing f(), restoring the original value afterward even if an exception is thrown.