Replace type expression with traits

boot/lexer.ll

@@ -131,6 +131,9 @@ defer                   {
 [A-Za-z_][A-Za-z0-9_]*  {
                             return yy::parser::make_IDENTIFIER(yytext, this->location);
                         }
+#[A-Za-z_][A-Za-z0-9_]* {
+                            return yy::parser::make_TRAIT(yytext + 1, this->location);
+                        }
 [0-9]+u                 {
                             return yy::parser::make_WORD(strtoul(yytext, NULL, 10), this->location);
                         }