monadlib 0.2 · OCaml Package

include BasePlus with type 'a m = 'a option

include BatInterfaces.Monad with type 'a m = 'a option

type 'a m = 'a option

The type of a monad producing values of type 'a.

val zero : unit -> 'a m

val plus : 'a m -> 'a m -> 'a m

val null : 'a m -> bool

null x implies that x is zero. If you do not want to or cannot answer whether a given x is zero, then null x should be false. I have provided this so that streams can be implemented more efficiently.

include Monad with type 'a m := 'a m

include BatInterfaces.Monad with type 'a m := 'a m

val bind : 'a m -> ('a -> 'b m) -> 'b m

Monadic binding.

bind m f executes first m then f, using the result of m.

include Applicative.Applicative with type 'a m := 'a m

include Applicative.Base with type 'a m := 'a m

val return : 'a -> 'a m

val (<*>) : ('a -> 'b) m -> 'a m -> 'b m

val lift1 : ('a -> 'b) -> 'a m -> 'b m

val lift2 : ('a -> 'b -> 'c) -> 'a m -> 'b m -> 'c m

val lift3 : ('a -> 'b -> 'c -> 'd) -> 'a m -> 'b m -> 'c m -> 'd m

val lift4 : 
  ('a -> 'b -> 'c -> 'd -> 'e) ->
  'a m ->
  'b m ->
  'c m ->
  'd m ->
  'e m

val (<$>) : ('a -> 'b) -> 'a m -> 'b m

Alias for lift1.

val sequence : 'a m list -> 'a list m

val map_a : ('a -> 'b m) -> 'a list -> 'b list m

val (<*) : 'a m -> 'b m -> 'a m

val (>*) : 'a m -> 'b m -> 'b m

val (>>=) : 'a m -> ('a -> 'b m) -> 'b m

val join : 'a m m -> 'a m

val filter_m : ('a -> bool m) -> 'a list -> 'a list m

val onlyif : bool -> unit m -> unit m

val unless : bool -> unit m -> unit m

val ignore : 'a m -> unit m

val filter : ('a -> bool) -> 'a m -> 'a m

val of_list : 'a list -> 'a m

val sum : 'a list m -> 'a m

val msum : 'a m list -> 'a m

val guard : bool -> 'a m -> 'a m

val transpose : 'a list m -> 'a m list

Generalises matrix transposition. This will loop infinitely if BasePlus.null cannot answer true for zeroes.