package alg_structs

  1. Overview
  2. Docs

Option provides sequencing of partial computations. E.g,

# Option.((+) <@> Some 5 <*> Some 7);;

- : int option = Option.Some 12

# Option.((+) <@> None <*> Some 5);;

- : int option = Option.None

include Seed with type 'a t = 'a Stdlib.Option.t
include Functor.S with type 'a t = 'a Stdlib.Option.t
include Functor.Seed with type 'a t = 'a Stdlib.Option.t
type 'a t = 'a Stdlib.Option.t

The principle type.

The type constructor t is the mapping of objects taking every type 'a to a type 'a t.

val map : f:('a -> 'b) -> 'a t -> 'b t

map ~f maps the function f : 'a -> 'b to a function 'f T : 'a T -> 'b T.

As an example, if T (x : u) : u t then map ~(f:u -> v) (T x) is T (f x) : v t. As a result, map is often thought of as applying f "in" T.

The function map is the mapping of arrows, taking every arrow 'a -> 'b to an arrow 'a t -> 'b t.

val (<@>) : ('a -> 'b) -> 'a t -> 'b t

Infix for map

val (|>>) : 'a t -> ('a -> 'b) -> 'b t

Mapped version of |> (which is flipped (<&>))

val return : 'a -> 'a t

return x is the minimal value of x in t

val apply : ('a -> 'b) t -> 'a t -> 'b t

apply (F f) (F x) is F (f x), i.e., f applied to x in t

val map2 : 'a t -> 'b t -> f:('a -> 'b -> 'c) -> 'c t

map2 ~f x y is return f <*> x <*> y, i.e., f "lifted" in to t and then applied to both x and y.

val (<*>) : ('a -> 'b) t -> 'a t -> 'b t

(F f) <*> (F x) is F (f x)

val (*>) : 'a t -> 'b t -> 'b t

a *> b sequences actions a and b but discards the value of a

val (<*) : 'a t -> 'b t -> 'a t

a <* b sequences actions a and b but discards the value of b

val both : 'a t -> 'b t -> ('a * 'b) t

both (F a) (F b) is F (a, b), i.e., it is the product of a and b in F

module Let_bind : sig ... end

Binding operators for use with the OCaml 4.08 extension. See the OCaml docs on binding operators for more information.