src/Pure/General/output_primitives.ML

restore output channels after shutdown, e.g. relevant for saved heap;

(*  Title:      Pure/General/output_primitives.ML
    Author:     Makarius

Primitives for Isabelle output channels.
*)

signature OUTPUT_PRIMITIVES =
sig
  type output = string
  type serial = int
  type properties = (string * string) list
  val ignore_outputs: output list -> unit
  val writeln_fn: output list -> unit
  val state_fn: output list -> unit
  val information_fn: output list -> unit
  val tracing_fn: output list -> unit
  val warning_fn: output list -> unit
  val legacy_fn: output list -> unit
  val error_message_fn: serial * output list -> unit
  val system_message_fn: output list -> unit
  val status_fn: output list -> unit
  val report_fn: output list -> unit
  val result_fn: properties -> output list -> unit
  val protocol_message_fn: properties -> output list -> unit
  val markup_fn: string * properties -> output * output
end;

structure Output_Primitives: OUTPUT_PRIMITIVES =
struct

type output = string;
type serial = int;
type properties = (string * string) list;

fun ignore_outputs (_: output list) = ();

val writeln_fn = ignore_outputs;
val state_fn = ignore_outputs;
val information_fn = ignore_outputs;
val tracing_fn = ignore_outputs;
val warning_fn = ignore_outputs;
val legacy_fn = ignore_outputs;
fun error_message_fn (_: serial, _: output list) = ();
val system_message_fn = ignore_outputs;
val status_fn = ignore_outputs;
val report_fn = ignore_outputs;
fun result_fn (_: properties) = ignore_outputs;
fun protocol_message_fn (_: properties) = ignore_outputs;

fun markup_fn (_: string * properties) = ("", "");

end;