+ (match idrefs with
+ | [] -> [t]
+ | desc::_ ->
+ let desc = Some desc in
+ (match l with
+ | `Keyword (k,_) -> [ Ast.Literal (`Keyword (k,(None,desc))) ]
+ | `Symbol (s,_) -> [ Ast.Literal (`Symbol (s,(None,desc))) ]
+ | `Number (n,_) -> [ Ast.Literal (`Number (n,(None,desc))) ]))