type exp = | Js_function of {arity : int;arrow : bool;
}| Js_literal of {
}| Js_exp_unknown
type raw_kind = | Raw_re| Raw_exp| Raw_program
type stmt = | Js_stmt_unknown
type code_info = | Exp of exp| Stmt of stmt
type t = {code : string;code_info : code_info;
}