Module `Prime_option`

Functions on the 'a option type.

val get : 'a option -> 'a: get (Some a) returns a, and get None raises Invalid_argument.

val get_or : 'a -> 'a option -> 'a: get_or d is a variant of get which maps None to d instead of raising an exception.

val get_else : (unit -> 'a) -> 'a option -> 'a: get_else h is a variant of get which calls h () to handle the None case instead of raising an exception.

val found : (unit -> 'a) -> 'a option: found f is try Some (f ()) with Not_found -> None.

val search : ('a -> 'b option) -> 'a option -> 'b option: search f None is None and search f (Some a) is f a.

val flatten : 'a option option -> 'a option: flatten maps Some (Some x) to Some x and other values to None.

val iter : ('a -> unit) -> 'a option -> unit: iter f (Some a) calls f a, and iter f None does nothing.

val map : ('a -> 'b) -> 'a option -> 'b option: map f None is None and map f (Some a) is Some (f a).

val fmap : ('a -> 'b option) -> 'a option -> 'b option: fmap f None is None and fmap f (Some a) is f a. Functions as filter ∘ map and as monadic bind.

val fold : ('a -> 'b -> 'b) -> 'a option -> 'b -> 'b: fold f None is the identity function and fold f (Some a) is f a.

val for_all : ('a -> bool) -> 'a option -> bool: for_all f None is true and for_all f (Some a) is f a.

val exists : ('a -> bool) -> 'a option -> bool: exists f None is false and exists f (Some a) is f a.

val filter : ('a -> bool) -> 'a option -> 'a option: filter f (Some a) returns Some a if f a is true; in other cases filter f a returns None.

val inter : ('a -> 'b -> 'c) -> 'a option -> 'b option -> 'c option
val union : ('a -> 'a -> 'a) -> 'a option -> 'a option -> 'a option
val compl : ('a -> 'b -> 'b) -> 'a option -> 'b option -> 'b option
val finter : ('a -> 'b -> 'c option) -> 'a option -> 'b option -> 'c option
val funion : ('a -> 'a -> 'a option) -> 'a option -> 'a option -> 'a option
val fcompl : ('a -> 'b -> 'b option) -> 'a option -> 'b option -> 'b option