basis-library/general/option.sig

   1 signature OPTION_GLOBAL =
   2    sig
   3       datatype 'a option = NONE | SOME of 'a
   4
   5       exception Option
   6
   7       val getOpt: 'a option * 'a -> 'a
   8       val isSome: 'a option -> bool
   9       val valOf: 'a option -> 'a
  10    end
  11
  12 signature OPTION =
  13    sig
  14       include OPTION_GLOBAL
  15
  16       val app: ('a -> unit) -> 'a option -> unit
  17       val compose: ('a -> 'b) * ('c -> 'a option) -> 'c -> 'b option
  18       val composePartial: ('a -> 'b option) * ('c -> 'a option) -> 'c -> 'b option
  19       val filter: ('a -> bool) -> 'a -> 'a option
  20       val join: 'a option option -> 'a option
  21       val map: ('a -> 'b) -> 'a option -> 'b option
  22       val mapPartial: ('a -> 'b option) -> 'a option -> 'b option
  23    end