Compatibility file for MLWorks version 1.0r2 or later.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Pure/ML-Systems/mlworks.ML	Tue Dec 16 18:58:16 1997 +0100
@@ -0,0 +1,102 @@
+(*  Title:      Pure/ML-Systems/mlworks.ML
+    ID:         $Id$
+    Author:     Lawrence C Paulson, Cambridge University Computer Laboratory
+    Copyright   1996  University of Cambridge
+
+Compatibility file for MLWorks version 1.0r2 or later.
+*)
+
+(*** Poly/ML emulation ***)
+
+(*Just for versions of MLWorks that don't provide the Option structure*)
+structure Option = General;
+
+(*To exit the system with an exit code -- an alternative to ^D *)
+fun exit 0 = (OS.Process.exit OS.Process.success): unit
+  | exit _ = OS.Process.exit OS.Process.failure;
+fun quit () = exit 0;
+
+(*To limit the printing depth [divided by 2 for comparibility with Poly/ML]*)
+fun print_depth n = ();
+
+(*Interface for toplevel pretty printers, see also Pure/install_pp.ML
+  CURRENTLY UNAVAILABLE*)
+fun make_pp path pprint = ();
+fun install_pp _ = ();
+
+
+(*** Character/string functions which are compatible with 0.93 and Poly/ML ***)
+
+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;
+
+
+(** 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, {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;
+
+
+(*** File handling ***)
+
+(*Get time of last modification; if file doesn't exist return an empty string*)
+fun file_info "" = ""
+  | file_info name = Time.toString (OS.FileSys.modTime name) handle _ =>"";
+
+
+(*** ML command execution ***)
+
+val tmpName = OS.FileSys.tmpName();
+
+(*Can one redirect 'use' directly to an instream?*)
+fun use_strings slist =
+  let val tmpFile = TextIO.openOut tmpName
+  in app (fn s => TextIO.output (tmpFile, s)) slist;
+     TextIO.closeOut tmpFile;
+     use tmpName
+  end;
+
+
+(*** System command execution ***)
+
+(*Execute an Unix command which doesn't take any input from stdin and
+  sends its output to stdout.
+  This could be done more easily by Unix.execute, but that function
+  doesn't use the PATH.*)
+fun execute command =
+  let val is = (OS.Process.system (command ^ " > " ^ tmpName);
+                TextIO.openIn tmpName);
+      val result = TextIO.inputAll is;
+  in TextIO.closeIn is;
+     OS.FileSys.remove tmpName;
+     result
+  end;
+
+
+(* getenv *)
+
+fun getenv var =
+  (case OS.Process.getEnv var of
+    NONE => ""
+  | SOME txt => txt);
+
+
+(*Non-printing and 8-bit chars are forbidden in string constants*)
+val needs_filtered_use = true;
+