Source file log.ml

(*****************************************************************************)
(*                                                                           *)
(* Open Source License                                                       *)
(* Copyright (c) 2019,2020 DaiLambda, Inc. <contact@dailambda.jp>            *)
(*                                                                           *)
(* Permission is hereby granted, free of charge, to any person obtaining a   *)
(* copy of this software and associated documentation files (the "Software"),*)
(* to deal in the Software without restriction, including without limitation *)
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(* Software is furnished to do so, subject to the following conditions:      *)
(*                                                                           *)
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(* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,  *)
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(* DEALINGS IN THE SOFTWARE.                                                 *)
(*                                                                           *)
(*****************************************************************************)

type level =
  | Debug
  | Info
  | Notice
  | Warning
  | Error
  | Fatal

type t = { f : 'a . (level -> ('a, Format.formatter, unit, unit) format4 -> 'a) }

let threshold = ref Notice

let default =
  let default level fmt =
    Format.kasprintf (fun s -> if level >= !threshold then prerr_endline s) fmt
  in
  { f= default }

let r = ref default

let set f = r := f

let log level fmt = !r.f level fmt

let lwt_log level fmt =
  Format.kasprintf (fun s -> log level "%s" s; Lwt.return_unit) fmt

let debug   fmt = log Debug fmt
let info    fmt = log Info fmt
let notice  fmt = log Notice fmt
let warning fmt = log Warning fmt
let error   fmt = log Error fmt
let fatal   fmt = log Fatal fmt

let lwt_debug   fmt = lwt_log Debug fmt
let lwt_info    fmt = lwt_log Info fmt
let lwt_notice  fmt = lwt_log Notice fmt
let lwt_warning fmt = lwt_log Warning fmt
let lwt_error   fmt = lwt_log Error fmt
let lwt_fatal   fmt = lwt_log Fatal fmt