(*  Title:      Pure/ML-Systems/mosml.ML

    ID:         $Id$

    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory

    Copyright   1999  University of Cambridge

Compatibility file for Moscow ML 2.01

NOTE: saving images does not work; may run it interactively as follows:

$ cd Isabelle/src/Pure

$ isabelle RAW_ML_SYSTEM

> val ml_system = "mosml";

> use "ML-Systems/mosml.ML";

> use "ROOT.ML";

> Session.finish ();

> cd "../FOL";

> use "ROOT.ML";

*)

(** ML system related **)

load "Obj";

load "Bool";

load "Int";

load "Real";

load "ListPair";

load "OS";

load "Process";

load "FileSys";

load "IO";

(*low-level pointer equality*)

local val cast : 'a -> int = Obj.magic

in fun pointer_eq (x:'a, y:'a) = (cast x = cast y) end;

(*proper implementation available?*)

structure IntInf =

struct

  open Int;

end;

structure Real =

struct

  open Real;

  val realFloor = real o floor;

end;

structure String =

struct

  fun isSuffix s1 s2 =

    let val n1 = size s1 and n2 = size s2

    in if n1 = n2 then s1 = s2 else n1 <= n2 andalso String.substring (s2, n2 - n1, n1) = s1 end;

  open String;

end;

structure Time =

struct

  open Time;

  fun toString t = Time.toString t

    handle Overflow => Real.toString (Time.toReal t);   (*workaround Y2004 bug*)

end;

structure OS =

struct

  open OS

  structure Process = Process

  structure FileSys = FileSys

end;

exception Option = Option.Option;

(*limit the printing depth*)

fun print_depth n =

 (Meta.printDepth := n div 2;

  Meta.printLength := n);

(*interface for toplevel pretty printers, see also Pure/install_pp.ML*)

(*the documentation refers to an installPP but I couldn't fine it!*)

fun make_pp path pprint = ();

fun install_pp _ = ();

(*dummy implementation*)

fun ml_prompts p1 p2 = ();

(*dummy implementation*)

fun profile (n: int) f x = f x;

(*dummy implementation*)

fun exception_trace f = f ();

(*dummy implementation*)

fun print x = x;

(** Compiler-independent timing functions **)

load "Timer";

fun start_timing () =

  let val CPUtimer = Timer.startCPUTimer();

      val time = Timer.checkCPUTimer(CPUtimer)

  in  (CPUtimer,time)  end;

fun end_timing (CPUtimer, {gc,sys,usr}) =

  let open Time  (*...for Time.toString, Time.+ and Time.- *)

      val {gc=gc2,sys=sys2,usr=usr2} = Timer.checkCPUTimer(CPUtimer)

  in  "User " ^ toString (usr2-usr) ^

      "  GC " ^ toString (gc2-gc) ^

      "  All "^ toString (sys2-sys + usr2-usr + gc2-gc) ^

      " secs"

      handle Time => ""

  end;

fun check_timer timer =

  let val {sys, usr, gc} = Timer.checkCPUTimer timer

  in (sys, usr, gc) end;

(* SML basis library fixes *)

structure TextIO =

struct

  fun canInput _ = raise IO.Io {cause = Fail "undefined", function = "canInput", name = ""};

  open TextIO;

  fun inputLine is =

    let val s = TextIO.inputLine is

    in if s = "" then NONE else SOME s end;

end;

(* bounded time execution *)

(*dummy implementation*)

fun interrupt_timeout time f x =

  f x;

(* ML command execution *)

(*Can one redirect 'use' directly to an instream?*)

fun use_text _ _ _ txt =

  let

    val tmp_name = FileSys.tmpName ();

    val tmp_file = TextIO.openOut tmp_name;

  in

    TextIO.output (tmp_file, txt);

    TextIO.closeOut tmp_file;

    use tmp_name;

    FileSys.remove tmp_name

  end;

fun use_file _ _ name = use name;

(** interrupts **)      (*Note: may get into race conditions*)

(* FIXME proper implementation available? *)

exception Interrupt;

fun ignore_interrupt f x = f x;

fun raise_interrupt f x = f x;

(** OS related **)

(* current directory *)

val cd = OS.FileSys.chDir;

val pwd = OS.FileSys.getDir;

(* 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 = FileSys.tmpName ();

    val is = (Process.system (command ^ " > " ^ tmp_name); TextIO.openIn tmp_name);

    val result = TextIO.inputAll is;

  in

    TextIO.closeIn is;

    FileSys.remove tmp_name;

    result

  end;

(*plain version; with return code*)

fun system cmd =

  if Process.system cmd = Process.success then 0 else 1;

val string_of_pid = Int.toString;

(* getenv *)

fun getenv var =

  (case Process.getEnv var of

    NONE => ""

  | SOME txt => txt);