(*  Title:      Pure/ML-Systems/smlnj.ML
    Author:     Carsten Clasohm and Markus Wenzel, TU Muenchen

Compatibility file for Standard ML of New Jersey versions 110.72.
*)

(** ML system related **)

(* restore old-style character / string functions *)

fun ord s = Char.ord (String.sub (s, 0));
val chr = str o Char.chr;
val explode = (map str) o String.explode;
val implode = String.concat;


(* New Jersey ML parameters *)

structure Compiler =
struct
  open Compiler;
  structure Control = Control;
  structure PrettyPrint = PrettyPrint;
  structure PPTable = CompilerPPTable;
  structure Interact = Backend.Interact;
end;

val _ =
 (Compiler.Control.Print.printLength := 1000;
  Compiler.Control.Print.printDepth := 350;
  Compiler.Control.Print.stringDepth := 250;
  Compiler.Control.Print.signatures := 2);


(* interrupts *)

exception Interrupt;

local

fun capture f x = ((f x): unit; NONE) handle exn => SOME exn;

fun release NONE = ()
  | release (SOME exn) = raise exn;

in

fun ignore_interrupt f x =
  let
    val old_handler = Signals.setHandler (Signals.sigINT, Signals.IGNORE);
    val result = capture f x;
    val _ = Signals.setHandler (Signals.sigINT, old_handler);
  in release result end;

fun raise_interrupt f x =
  let
    val interrupted = ref false;
    val result = ref NONE;
    val old_handler = Signals.inqHandler Signals.sigINT;
  in
    SMLofNJ.Cont.callcc (fn cont =>
      (Signals.setHandler (Signals.sigINT, Signals.HANDLER (fn _ => (interrupted := true; cont)));
      result := capture f x));
    Signals.setHandler (Signals.sigINT, old_handler);
    if ! interrupted then raise Interrupt else release (! result)
  end;

end;


(* basis library incompatibilities *)

structure TextIO =
struct
  open TextIO;

  fun inputLine is =
    (case TextIO.inputLine is of
      SOME str => str
    | NONE => "")
    handle IO.Io _ => raise Interrupt;
end;


(* Poly/ML emulation *)

fun quit () = exit 0;

(*limit the printing depth -- divided by 2 for comparibility with Poly/ML*)
fun print_depth n =
 (Compiler.Control.Print.printDepth := n div 2;
  Compiler.Control.Print.printLength := n);

(*Poly/ML-like prompts*)
Compiler.Control.primaryPrompt := "> ";
Compiler.Control.secondaryPrompt := "# ";


(** Compiler-independent timing functions **)

(*Note start point for timing*)
fun startTiming() =
  let val CPUtimer = Timer.startCPUTimer();
      val time = Timer.checkCPUTimer(CPUtimer)
  in  (CPUtimer,time)  end;

(*Finish timing and return string*)
fun endTiming (CPUtimer, {sys,usr}) =
  let open Time  (*...for Time.toString, Time.+ and Time.- *)
      val {sys=sys2,usr=usr2} = Timer.checkCPUTimer(CPUtimer)
  in  "User " ^ toString (usr2-usr) ^
      "  All "^ toString (sys2-sys + usr2-usr) ^
      " secs"
      handle Time => ""
  end;

fun checkTimer timer =
  let
    val {sys, usr} = Timer.checkCPUTimer timer;
    val gc = Timer.checkGCTime timer;    (* FIXME already included in usr? *)
  in (sys, usr, gc) end;


(* toplevel pretty printing (see also Pure/install_pp.ML) *)

fun make_pp path pprint =
  let
    open Compiler.PrettyPrint;

    fun pp pps obj =
      pprint obj
        (string pps, openHOVBox pps o Rel,
          fn wd => break pps {nsp=wd, offset=0}, fn () => newline pps,
          fn () => closeBox pps);
  in
    (path, pp)
  end;

fun install_pp (path, pp) = Compiler.PPTable.install_pp path pp;


(* ML command execution *)

val use_strings = Compiler.Interact.useStream o TextIO.openString o implode;



(** OS related **)

(* system command execution *)

(*execute Unix command which doesn't take any input from stdin and
  sends its output to stdout; could be done more easily by Unix.execute,
  but that function doesn't use the PATH*)
fun execute command =
  let
    val tmp_name = OS.FileSys.tmpName ();
    val is = (OS.Process.system (command ^ " > " ^ tmp_name); TextIO.openIn tmp_name);
    val result = TextIO.inputAll is;
  in
    TextIO.closeIn is;
    OS.FileSys.remove tmp_name;
    result
  end;


(* file handling *)

(*get time of last modification; if file doesn't exist return an empty string*)
fun file_info "" = ""		(* FIXME !? *)
  | file_info name = Time.toString (OS.FileSys.modTime name) handle _ => "";


(* getenv *)

fun getenv var =
  (case OS.Process.getEnv var of
    NONE => ""
  | SOME txt => txt);


(* non-ASCII input (see also Thy/use.ML) *)

val needs_filtered_use = false;