[parser] adding support for expressions

src/lexer.mll

@@ -15,6 +15,24 @@
       ("var", VAR);
       ("int", INT);
       ("bool", BOOL);
+      ("<=", BO_le);
+      (">=", BO_ge);
+      ("not", MO_not);
+      ("mod", BO_mod);
+      ("&&", BO_and);
+      ("and", BO_and);
+      ("||", BO_or);
+      ("or", BO_or);
+      ("<>", BO_neq);
+      ("if", IF);
+      ("then", THEN);
+      ("else", ELSE);
+      ("≤", BO_le);
+      ("≥", BO_ge );
+      ("¬", MO_not);
+      ("pre", PRE);
+      ("true", CONST_BOOL(true));
+      ("false", CONST_BOOL(false));
       ];
     fun s ->
       try Hashtbl.find h s with Not_found -> IDENT s
@@ -27,12 +45,21 @@ let ident = alpha (alpha | digit | '_')*
 rule token = parse
     ['\n' ' ' '\t'] { token lexbuf }     (* skip blanks and newlines *)
   | ident           { id_or_keywork (lexeme lexbuf) }
+  | digit+          { CONST_INT(int_of_string (lexeme lexbuf)) }
   | ','             { COMMA }
   | '='             { EQUAL }
   | '('             { LPAREN }
   | ')'             { RPAREN }
   | ';'             { SEMICOL }
   | ':'             { COLON }
+  | '<'             { BO_lt }
+  | '>'             { BO_gt }
+  | '+'             { PLUS }
+  | '-'             { MINUS }
+  | '*'             { BO_mul }
+  | '/'             { BO_div }
+  | '%'             { BO_mod }
+  | "->"            { ARROW }
   | eof             { EOF }
   | _               { raise (Lexing_error (Format.sprintf "Erruer à la vue de %s" (lexeme lexbuf)))}