Monad (core.Core.Monad)

include Base__.Monad_intf.S_without_syntax with type a t := a t

type 'a t

A monad is an abstraction of the concept of sequencing of computations. A value of type 'a monad represents a computation that returns a value of type 'a.

include Base__.Monad_intf.Infix with type a t := a t

type 'a t

val (>>=) : 'a t ‑> ('a ‑> 'b t) ‑> 'b t

t >>= f returns a computation that sequences the computations represented by two monad elements. The resulting computation first does t to yield a value v, and then runs the computation returned by f v.

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

t >>| f is t >>= (fun a -> return (f a)).

module Monad_infix : Base__.Monad_intf.Infix with type a t := a t

val bind : 'a t ‑> f:('a ‑> 'b t) ‑> 'b t

bind t ~f = t >>= f

val return : 'a ‑> 'a t

return v returns the (trivial) computation that returns v.

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

map t ~f is t >>| f.

val join : 'a t t ‑> 'a t

join t is t >>= (fun t' -> t').

val ignore_m : 'a t ‑> unit t

ignore_m t is map t ~f:(fun _ -> ()). ignore_m used to be called ignore, but we decided that was a bad name, because it shadowed the widely used Pervasives.ignore. Some monads still do let ignore = ignore_m for historical reasons.

val all : 'a t list ‑> 'a list t

val all_ignore : unit t list ‑> unit t