Module EchoSource

Sourcetype out_type =
  1. | Stdout
  2. | Stderr
  3. | File of string

The type of output destinations for log messages.

Sourceval set_out : out_type -> unit

set_out destination sets the output destination for subsequent log messages. If not called, logging defaults to a system-defined output (e.g., stdout).

Sourceval trace : ('a, unit, string, unit) format4 -> 'a

trace fmt ... logs a TRACE-level message using a format string. Use for verbose or diagnostic output.

Sourceval info : ('a, unit, string, unit) format4 -> 'a

info fmt ... logs an INFO-level message using a format string. Use for general information and progress updates.

Sourceval warn : ('a, unit, string, unit) format4 -> 'a

warn fmt ... logs a WARN-level message using a format string. Use for potential issues that do not interrupt execution.

Sourceval error : ('a, unit, string, unit) format4 -> 'a

error fmt ... logs an ERROR-level message using a format string. Use for recoverable errors or failures.

Sourceval fatal : ('a, unit, string, unit) format4 -> 'a

fatal fmt ... logs a FATAL-level message using a format string. Use for unrecoverable errors; may imply imminent shutdown.

Sourceval flush : unit -> unit

flush () forces any buffered log output to be written immediately. Useful if output is line-buffered or writing to a file.