balance.sig

   1 signature BALANCE =
   2 sig
   3     type balance = {id :int, name : string, amount : real}
   4
   5     val addBalance : string -> int
   6     val lookupBalance : int -> balance
   7     val modBalance : balance -> unit
   8     val deleteBalance : int -> unit
   9     val listBalances : unit -> balance list
  10     val listOwnedBalances : unit -> balance list
  11     val listUnownedBalances : unit -> balance list
  12     val listBalanceUsers : int -> Init.user list
  13     val listNegativeOwnedBalances : unit -> balance list
  14
  15     val validBalanceName : string -> bool
  16     val balanceNameToId : string -> int option
  17
  18     val sumOwnedBalances : unit -> real
  19     val isNegative : balance -> bool
  20 end