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

    ID:         $Id$

    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory

    Copyright   1991  University of Cambridge

Compatibility file for Poly/ML (versions 2.x and 3.x).

*)

open PolyML ExtendedIO;

(*needs the Basis Library emulation*)

use "basis.ML";

structure String =

  struct

  fun substring (s,i,j) = StringBuiltIns.substring (s, i+1, j)

                          handle Substring => raise Subscript

  end;

(** ML system related **)

(** Compiler-independent timing functions **)

(*Note start point for timing*)

fun startTiming() = System.processtime ();

(*Finish timing and return string*)

fun endTiming before =

  "User + GC: " ^

  makestring (real (System.processtime () - before) / 10.0) ^

  " secs";

(* prompts *)

fun ml_prompts p1 p2 = (PolyML.Compiler.prompt1 := p1; PolyML.Compiler.prompt2 := p2);

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

fun make_pp _ pprint (str, blk, brk, en) obj =

  pprint obj (str, fn ind => blk (ind, false), fn wd => brk (wd, 0),

    fn () => brk (99999, 0), en);

(* ML command execution -- 'eval' *)

fun use_text verbose txt =

  let

    val in_buffer = ref (explode txt);

    val out_buffer = ref ([]: string list);

    fun get () =

      (case ! in_buffer of

        [] => ""

      | c :: cs => (in_buffer := cs; c));

    fun put s = out_buffer := s :: ! out_buffer;

    fun exec () =

      (case ! in_buffer of

        [] => ()

      | _ => (PolyML.compiler (get, put) (); exec ()));

    fun show_output () = print (implode (rev (! out_buffer)));

  in

    exec () handle exn => (show_output (); raise exn);

    if verbose then show_output () else ()

  end;

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

fun mask_interrupt f x = f x;

fun unmask_interrupt f x = f x;

fun exhibit_interrupt f x = f x;

(** OS related **)

local

fun drop_last [] = []

  | drop_last [x] = []

  | drop_last (x :: xs) = x :: drop_last xs;

val drop_last_char = implode o drop_last o explode;

in

(* system command execution *)

(*execute Unix command which doesn't take any input from stdin and

  sends its output to stdout*)

fun execute command =

  let

    val (is, os) =  ExtendedIO.execute command;

    val result = input (is, 999999);

  in

    close_out os;

    close_in is;

    result

  end;

(* file handling *)

(*get time of last modification*)

fun file_info name = Int.toString (System.filedate name) handle _ => "";

structure OS =

struct

  structure FileSys =

  struct

    val chDir = PolyML.cd;

    fun remove name = (execute ("rm " ^ name); ());

    fun getDir () = drop_last_char (execute "pwd");

  end;

end;

(* getenv *)

fun getenv var = drop_last_char

  (execute ("env | grep '^" ^ var ^ "=' | sed -e 's/" ^ var ^ "=//'"));

end;

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

val needs_filtered_use =

  (case explode ml_system of

    "p" :: "o" :: "l" :: "y" :: "m" :: "l" :: "-" :: "3" :: _ => true

  | _ => false);