let match_date = Re.Str.regexp {|[0-9]+/[0-9]+/[0-9]+|}

type t =
  | Null
  | Error of string
  | Content of string
  | Integer of int
  | Float of float

let to_string = function
  | Null -> ""
  | Error s -> s
  | Integer i -> string_of_int i
  | Float f -> string_of_float f
  | Content c -> (
      match String.starts_with ~prefix:"0" c with
      | false -> c
      | true ->
          (* If the string is a date, do not escape it *)
          if Re.Str.string_match match_date c 0 then c
          else String.concat "" [ "=\""; c; "\"" ])