contract Twisto {
  fun initialize(metadata, supply, cap) =
    if load(0) == 0 then
      let ignored = store(0, caller) in
      let ignored = store(1, metadata) in
      let ignored = store(2, cap) in
      let ignored = store(3, supply) in
      store(caller, supply)
    else 0;

  fun metadata() = load(1);
  fun total_supply() = load(3);
  fun cap() = load(2);
  fun balance_of(account) = load(account);

  fun transfer(to, amount) =
    let from = caller in
    let balance = load(from) in
    if amount > balance then 0 else
      let ignored = store(from, balance - amount) in
      store(to, load(to) + amount);

  fun mint(to, amount) =
    let owner = load(0) in
    let supply = load(3) in
    let ceiling = load(2) in
    if caller == owner then
      if ceiling < supply + amount then 0 else
        let ignored = store(3, supply + amount) in
        store(to, load(to) + amount)
    else 0;

  fun burn(amount) =
    let account = caller in
    let balance = load(account) in
    let supply = load(3) in
    if amount > balance then 0 else
      let ignored = store(account, balance - amount) in
      store(3, supply - amount);
}