Added driver and parsing holes

src/Driver.ml

@@ -0,0 +1,41 @@
+open Ostap
+
+let parse infile =
+  let s = Util.read infile in
+  Util.parse
+    (object
+       inherit Matcher.t s
+       inherit Util.Lexers.decimal s
+       inherit Util.Lexers.skip [
+	 Matcher.Skip.whitespaces " \t\n";
+	 Matcher.Skip.lineComment "--";
+	 Matcher.Skip.nestedComment "(*" "*)"
+       ] s
+     end
+    )
+    (ostap (!(Language.parse) -EOF))
+
+let main =
+  try
+    let interpret  = Sys.argv.(1) = "-i"  in
+    let stack      = Sys.argv.(1) = "-s"  in
+    let infile     = Sys.argv.(2) in
+    match parse infile with
+    | `Ok ((_, stmt) as prog) ->
+       let rec read acc =
+         try
+	   let r = read_int () in
+	   Printf.printf "> ";
+	   read (acc @ [r]) 
+         with End_of_file -> acc
+       in
+       let input = read [] in	
+       let output = 
+	 if interpret 
+	 then Language.eval prog input 
+	 else SM.eval (SM.compile prog) input
+       in
+       List.iter (fun i -> Printf.printf "%d\n" i) output
+    | `Fail er -> Printf.eprintf "Syntax error: %s\n" er
+  with Invalid_argument _ ->
+    Printf.printf "Usage: rc [-i] <input file.expr>\n"