Similarly updated calc-param.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/menhir@351 0f8b5475-4b4e-0410-85a8-ee3154a6bfe7

demos/calc-param/calc.ml

@@ -23,17 +23,31 @@ module FloatParser =
 
 (* The rest is as usual. *)
 
+let process (line : string) =
+  let linebuf = Lexing.from_string line in
+  try
+    (* Run the parser on this line of input. *)
+    Printf.printf "%f\n%!" (FloatParser.main Lexer.token linebuf)
+  with
+  | Lexer.Error msg ->
+      Printf.fprintf stderr "%s%!" msg
+  | FloatParser.Error ->
+      Printf.fprintf stderr "At offset %d: syntax error.\n%!" (Lexing.lexeme_start linebuf)
+
+let process (optional_line : string option) =
+  match optional_line with
+  | None ->
+      ()
+  | Some line ->
+      process line
+
+let rec repeat channel =
+  (* Attempt to read one line. *)
+  let optional_line, continue = Lexer.line channel in
+  process optional_line;
+  if continue then
+    repeat channel
+  
 let () =
-  let stdinbuf = Lexing.from_channel stdin in
-  while true do
-    (* Read line by line. *)
-    let linebuf = Lexing.from_string (Lexer.line stdinbuf) in
-    try
-      (* Run the parser on a single line of input. *)
-      Printf.printf "%.1f\n%!" (FloatParser.main Lexer.token linebuf)
-    with
-    | Lexer.Error msg ->
-	Printf.fprintf stderr "%s%!" msg
-    | FloatParser.Error ->
-	Printf.fprintf stderr "At offset %d: syntax error.\n%!" (Lexing.lexeme_start linebuf)
-  done
+  repeat (Lexing.from_channel stdin)
+

demos/calc-param/lexer.mll

@@ -5,11 +5,24 @@
 
 }
 
+(* This rule looks for a single line, terminated with '\n' or eof.
+   It returns a pair of an optional string (the line that was found)
+   and a Boolean flag (false if eof was reached). *)
+
 rule line = parse
 | ([^'\n']* '\n') as line
-    { line }
+    (* Normal case: one line, no eof. *)
+    { Some line, true }
 | eof
-    { exit 0 }
+    (* Normal case: no data, eof. *)
+    { None, false }
+| ([^'\n']+ as line) eof
+    (* Special case: some data but missing '\n', then eof.
+       Consider this as the last line, and add the missing '\n'. *)
+    { Some (line ^ "\n"), false }
+
+(* This rule analyzes a single line and turns it into a stream of
+   tokens. *)
 
 and token = parse
 | [' ' '\t']
@@ -30,8 +43,6 @@ and token = parse
     { LPAREN }
 | ')'
     { RPAREN }
-| eof
-    { exit 0 }
 | _
     { raise (Error (Printf.sprintf "At offset %d: unexpected character.\n" (Lexing.lexeme_start lexbuf))) }