Introducing format %$ (to print strings with variables substitution)

and %! (to flush the output). See printf.mli for details.


git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@5517 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

stdlib/printf.ml

@@ -113,6 +113,11 @@ let extract_format fmt start stop widths =
               Buffer.add_char b c; fill_format (succ i) w
       in fill_format start (List.rev widths)
 
+let substitute_string f s =
+  let b = Buffer.create (2 * String.length s) in
+  Buffer.add_substitute b f s;
+  Buffer.contents b;;
+
 let format_int_with_conv conv fmt i =
    match conv with
    | 'b' -> format_binary_int fmt i
@@ -212,8 +217,11 @@ let scan_format fmt pos cont_s cont_a cont_t cont_f =
         | _ ->
             bad_format fmt pos
         end
-    | '$' ->
+    | '!' ->
         Obj.magic (cont_f (succ i))
+    | '$' ->
+        Obj.magic (fun f s ->
+          cont_s (substitute_string f s) (succ i))
     | _ ->
         bad_format fmt pos
   in scan_flags [] (pos + 1)
@@ -281,5 +289,3 @@ let bprintf dest fmt =
     printer dest; doprn i
   and cont_f i = doprn i
   in doprn 0
-
-

stdlib/printf.mli

@@ -63,7 +63,8 @@ val fprintf : out_channel -> ('a, out_channel, unit, unit) format -> 'a
      in the output of [fprintf] at the current point.
    - [t]: same as [%a], but takes only one argument (with type
      [out_channel -> unit]) and apply it to [outchan].
-   - [$]: take no argument and flush the output.
+   - [!]: take no argument and flush the output.
+   - [$]: take two arguments.
    - [%]: take no argument and output one [%] character.
 
    The optional flags include:

typing/typecore.ml

@@ -682,7 +682,7 @@ let type_format loc fmt =
     and scan_conversion i j =
       if j >= len then incomplete i else
       match fmt.[j] with
-      | '%' | '$' -> scan_format (j + 1)
+      | '%' | '!' -> scan_format (j + 1)
       | 's' | 'S' | '[' -> conversion j Predef.type_string
       | 'c' | 'C' -> conversion j Predef.type_char
       | 'b' | 'd' | 'i' | 'o' | 'x' | 'X' | 'u' | 'N' ->
@@ -690,10 +690,15 @@ let type_format loc fmt =
       | 'f' | 'e' | 'E' | 'g' | 'G' | 'F' -> conversion j Predef.type_float
       | 'B' -> conversion j Predef.type_bool
       | 'a' ->
-          let ty_arg = newvar() in
+          let ty_arg = newvar () in
           let ty_a = ty_arrow ty_input (ty_arrow ty_arg ty_aresult) in 
           let ty_aresult, ty_result = conversion j ty_arg in
           ty_aresult, ty_arrow ty_a ty_result
+      | '$' ->
+          let ty_arg = Predef.type_string in
+          let ty_f = ty_arrow Predef.type_string Predef.type_string in 
+          let ty_aresult, ty_result = conversion j ty_arg in
+          ty_aresult, ty_arrow ty_f ty_result
       | 'r' ->
           let ty_res = newvar() in
           let ty_r = ty_arrow ty_input ty_res in