First (base.Base.Either.First)

type ('a, 'b) t = ( 'a, 'b ) t

include Monad.S2 with type ('a, 'b) t := ( 'a, 'b ) t

val (>>=) : ( 'a, 'e ) t -> ( 'a -> ( 'b, 'e ) t ) -> ( 'b, 'e ) t

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

module Let_syntax : sig ... end

module Monad_infix : sig ... end

val bind : ( 'a, 'e ) t -> f:( 'a -> ( 'b, 'e ) t ) -> ( 'b, 'e ) t

val join : ( ( 'a, 'e ) t, 'e ) t -> ( 'a, 'e ) t

val ignore_m : ( _, 'e ) t -> ( unit, 'e ) t

include Applicative.S2 with type ('a, 'b) t := ( 'a, 'b ) t

val return : 'a -> ( 'a, _ ) t

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

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

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

val (<*) : ( 'a, 'e ) t -> ( unit, 'e ) t -> ( 'a, 'e ) t

val (*>) : ( unit, 'e ) t -> ( 'a, 'e ) t -> ( 'a, 'e ) t

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

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

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

val map3 : 
  ( 'a, 'e ) t ->
  ( 'b, 'e ) t ->
  ( 'c, 'e ) t ->
  f:( 'a -> 'b -> 'c -> 'd ) ->
  ( 'd, 'e ) t

val all : ( 'a, 'e ) t list -> ( 'a list, 'e ) t

val all_unit : ( unit, 'e ) t list -> ( unit, 'e ) t

module Applicative_infix : sig ... end

val value : ( 'a, _ ) t -> default:'a -> 'a

val to_option : ( 'a, _ ) t -> 'a option

val with_return : ( 'a With_return.return -> 'b ) -> ( 'a, 'b ) t

val combine : 
  ( 'a, 'd ) t ->
  ( 'b, 'd ) t ->
  f:( 'a -> 'b -> 'c ) ->
  other:( 'd -> 'd -> 'd ) ->
  ( 'c, 'd ) t

val combine_all : 
  ( 'a, 'b ) t list ->
  f:( 'b -> 'b -> 'b ) ->
  ( 'a list, 'b ) t

val combine_all_unit : 
  ( unit, 'b ) t list ->
  f:( 'b -> 'b -> 'b ) ->
  ( unit, 'b ) t