XDuce

(* XDuce program: Address book transformation *)

type Name = <name>[String]</name>
type Email = <email>[String]</email>
type Person = <person>[Name, Email]</person>
type AddressBook = <addressbook>[Person*]</addressbook>

fun transform(p : Person) : Person =
  match p with
  | <person>[<name>[n]</name>, <email>[e]</email>]</person> ->
      <person>
        <name>[uppercase(n)]</name>
        <email>[e]</email>
      </person>

fun uppercase(s : String) : String =
  (* Uppercase transformation would be implemented here *)
  s

fun processBook(ab : AddressBook) : AddressBook =
  match ab with
  | <addressbook>[ps]</addressbook> ->
      <addressbook>[map(transform, ps)]</addressbook>

(* Example usage *)
let input : AddressBook =
  <addressbook>
    <person>
      <name>John Doe</name>
      <email>john@example.com</email>
    </person>
    <person>
      <name>Jane Smith</name>
      <email>jane@example.com</email>
    </person>
  </addressbook>

let output = processBook(input)