Log.ReporterReporting.
The type for log message reporters. kmsg is never invoked with a level of Quiet or with a level smaller than the reporting level.
val nop : tnop is a logger that reports nothing.
val default : tdefault is the default reporter. It logs Log.level.Stdout messages on Fmt.stdout and all other messages on Fmt.stderr.
val get : unit -> tget () is the reporter.
val set : t -> unitset r sets the reporter to r.