character set difference

git-svn-id: http://caml.inria.fr/svn/ocaml/trunk@6269 f963ae5c-01c2-4b8c-9fe0-0dff7051ff02

lex/cset.ml

@@ -11,6 +11,9 @@
 (*                                                                     *)
 (***********************************************************************)
 
+(* $Id$ *)
+
+
 exception Bad
 
 type t = (int * int) list

lex/cset.mli

@@ -11,9 +11,12 @@
 (*                                                                     *)
 (***********************************************************************)
 
+(* $Id$ *)
+
 (* Set of characters encoded as list of intervals *)
 
 type t 
+exception Bad
 
 val empty : t
 val is_empty : t -> bool

lex/lexer.mll

@@ -186,6 +186,7 @@ rule main = parse
   | ')'  { Trparen }
   | '^'  { Tcaret }
   | '-'  { Tdash }
+  | '#'  { Tsharp }
   | eof  { Tend }
   | _
     { raise_lexical_error lexbuf

lex/main.ml

@@ -79,7 +79,13 @@ let main () =
     Common.close_tracker tr;
     Sys.remove dest_name;
     begin match exn with
-      Parsing.Parse_error ->
+    | Cset.Bad ->
+        let p = Lexing.lexeme_start_p lexbuf in
+        Printf.fprintf stderr
+          "File \"%s\", line %d, character %d: character set expected.\n"
+          p.Lexing.pos_fname p.Lexing.pos_lnum
+          (p.Lexing.pos_cnum - p.Lexing.pos_bol)
+    | Parsing.Parse_error ->
         let p = Lexing.lexeme_start_p lexbuf in
         Printf.fprintf stderr
           "File \"%s\", line %d, character %d: syntax error.\n"

lex/parser.mly

@@ -40,6 +40,10 @@ let rec remove_as = function
   | Alternative (e1, e2) -> Alternative (remove_as e1, remove_as e2)
   | Repetition e -> Repetition (remove_as e)
 
+let as_cset = function
+  | Characters s -> s
+  | _ -> raise Cset.Bad
+
 %}
 
 %token <string> Tident
@@ -47,9 +51,10 @@ let rec remove_as = function
 %token <string> Tstring
 %token <Syntax.location> Taction
 %token Trule Tparse Tparse_shortest Tand Tequal Tend Tor Tunderscore Teof Tlbracket Trbracket
-%token Tstar Tmaybe Tplus Tlparen Trparen Tcaret Tdash Tlet Tas
+%token Tstar Tmaybe Tplus Tlparen Trparen Tcaret Tdash Tlet Tas Tsharp
 
 %right Tas
+%left Tsharp
 %left Tor
 %nonassoc CONCAT
 %nonassoc Tmaybe Tstar Tplus
@@ -131,6 +136,12 @@ regexp:
         { Alternative(Epsilon, $1) }
   | regexp Tplus
         { Sequence(Repetition (remove_as $1), $1) }
+  | regexp Tsharp regexp
+        {
+          let s1 = as_cset $1
+          and s2 = as_cset $3 in
+          Characters (Cset.diff s1 s2)
+        } 
   | regexp Tor regexp
         { Alternative($1,$3) }
   | regexp regexp %prec CONCAT