add quoted idents

sw/tools/fp_lexer.mll

@@ -10,6 +10,7 @@ rule token = parse
   | ['0'-'9']+ { INT (int_of_string (Lexing.lexeme lexbuf)) }
   | ['0'-'9']+'.'['0'-'9']* { FLOAT (float_of_string (Lexing.lexeme lexbuf)) }
   | '$'?['a'-'z' '_' 'A'-'Z'] (['a'-'z' 'A'-'Z' '_' '.' '0'-'9']*) { IDENT (Lexing.lexeme lexbuf) }
+  | '\''[^'\'']+'\'' { let s = Lexing.lexeme lexbuf in IDENT (String.sub s 1 (String.length s - 2)) }
   | ',' { COMMA }
   | ';' { SEMICOLON }
   | ':' { COLON }