// handle commands
public static (Event Event, AccountState NewState) Debit
(this AccountState @this, MakeTransfer transfer)
{
var evt = transfer.ToEvent();
var newState = @this.Apply(evt);
return(evt, newState);
}
public static AccountState Apply(this AccountState @this, Event evt)
=> new Pattern <AccountState>
{
(DepositedCash e) => @this.Credit(e.Amount),
(DebitedTransfer e) => @this.Debit(e.DebitedAmount),
(FrozeAccount e) => @this.WithStatus(AccountStatus.Frozen),
}
.Match(evt);