1 files changed, 83 insertions, 0 deletions
diff --git a/plugins/syntax/ascii_syntax.ml b/plugins/syntax/ascii_syntax.ml
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+(***********************************************************************)
+(*  v      *   The Coq Proof Assistant  /  The Coq Development Team    *)
+(* <O___,, *        INRIA-Rocquencourt  &  LRI-CNRS-Orsay              *)
+(*   \VV/  *************************************************************)
+(*    //   *      This file is distributed under the terms of the      *)
+(*         *       GNU Lesser General Public License Version 2.1       *)
+(***********************************************************************)
+
+(*i $Id$ i*)
+
+open Pp
+open Util
+open Names
+open Pcoq
+open Rawterm
+open Topconstr
+open Libnames
+open Coqlib
+open Bigint
+
+exception Non_closed_ascii
+
+let make_dir l = make_dirpath (List.map id_of_string (List.rev l))
+let make_kn dir id = Libnames.encode_mind (make_dir dir) (id_of_string id)
+let make_path dir id = Libnames.make_path (make_dir dir) (id_of_string id)
+
+let ascii_module = ["Coq";"Strings";"Ascii"]
+
+let ascii_path = make_path ascii_module "ascii"
+
+let ascii_kn = make_kn ascii_module "ascii"
+let path_of_Ascii = ((ascii_kn,0),1)
+let static_glob_Ascii  = ConstructRef path_of_Ascii
+
+let make_reference id = find_reference "Ascii interpretation" ascii_module id
+let glob_Ascii = lazy (make_reference "Ascii")
+
+open Lazy
+
+let interp_ascii dloc p =
+  let rec aux n p =
+     if n = 0 then [] else
+     let mp = p mod 2 in
+     RRef (dloc,if mp = 0 then glob_false else glob_true)
+     :: (aux (n-1) (p/2)) in
+  RApp (dloc,RRef(dloc,force glob_Ascii), aux 8 p)
+
+let interp_ascii_string dloc s =
+  let p =
+    if String.length s = 1 then int_of_char s.[0]
+    else
+      if String.length s = 3 & is_digit s.[0] & is_digit s.[1] & is_digit s.[2]
+      then int_of_string s
+      else
+	user_err_loc (dloc,"interp_ascii_string",
+	  str "Expects a single character or a three-digits ascii code.") in
+  interp_ascii dloc p
+
+let uninterp_ascii r =
+  let rec uninterp_bool_list n = function
+    | [] when n = 0 -> 0
+    | RRef (_,k)::l when k = glob_true  -> 1+2*(uninterp_bool_list (n-1)  l)
+    | RRef (_,k)::l when k = glob_false -> 2*(uninterp_bool_list (n-1) l)
+    | _ -> raise Non_closed_ascii in
+  try
+    let rec aux = function
+    | RApp (_,RRef (_,k),l) when k = force glob_Ascii -> uninterp_bool_list 8 l
+    | _ -> raise Non_closed_ascii in
+    Some (aux r)
+  with
+   Non_closed_ascii -> None
+
+let make_ascii_string n =
+  if n>=32 && n<=126 then String.make 1 (char_of_int n)
+  else Printf.sprintf "%03d" n
+
+let uninterp_ascii_string r = Option.map make_ascii_string (uninterp_ascii r)
+
+let _ =
+  Notation.declare_string_interpreter "char_scope"
+    (ascii_path,ascii_module)
+    interp_ascii_string
+    ([RRef (dummy_loc,static_glob_Ascii)], uninterp_ascii_string, true)