Make the datalog prover lexer correspond to the acg one

src/datalog.prover/db_lexer.mll

@@ -3,14 +3,16 @@
 }
 
 let newline = ('\010' | '\013' | "\013\010")
-let letter = ['a'-'z' 'A'-'Z']
+let letter = ['a'-'z' 'A'-'Z'  'µ' 'À'-'Ö' 'Ø'-'Ý' 'ß'-'ö' 'ø'-'ÿ']
 let digit = ['0'-'9']
 let string = (letter|digit|'_')*'\''*
   
+let symbol = ['|' '!' '"' '#' '$' '%' '&' '\'' '*' '+' '-' '/' '<' '>' '?' '@' '\\' '^' '`'  '~' ]
+
   rule lexer =
   parse
   | [' ' '\t'] {lexer lexbuf}
-  | newline {lexer lexbuf}
+  | newline {let () = Lexing.new_line lexbuf in lexer lexbuf}
   | "(*" {comment 1 lexbuf}
   | "*)" {failwith "Unstarted comments"}
   | eof {EOI}
@@ -22,6 +24,7 @@ let string = (letter|digit|'_')*'\''*
   | "/" {SLASH}
   | "?" {QUESTION_MARK}
   | letter string {IDENT (Lexing.lexeme lexbuf)}
+  | symbol {IDENT (Lexing.lexeme lexbuf)}
   | '-'?digit+ {let s = Lexing.lexeme lexbuf in
 	    INT (int_of_string s)}
 and comment level =