ocaml-base-compiler

Official release 4.14.0
Library stdlib
Module Stdlib . Either
type ('a, 'b) t =
| Left of 'a
| Right of 'b

A value of ('a, 'b) Either.t contains either a value of 'a or a value of 'b

val left : 'a -> ( 'a, 'b ) t

left v is Left v.

val right : 'b -> ( 'a, 'b ) t

right v is Right v.

val is_left : ( 'a, 'b ) t -> bool

is_left (Left v) is true, is_left (Right v) is false.

val is_right : ( 'a, 'b ) t -> bool

is_right (Left v) is false, is_right (Right v) is true.

val find_left : ( 'a, 'b ) t -> 'a option

find_left (Left v) is Some v, find_left (Right _) is None

val find_right : ( 'a, 'b ) t -> 'b option

find_right (Right v) is Some v, find_right (Left _) is None

val map_left : ( 'a1 -> 'a2 ) -> ( 'a1, 'b ) t -> ( 'a2, 'b ) t

map_left f e is Left (f v) if e is Left v and e if e is Right _.

val map_right : ( 'b1 -> 'b2 ) -> ( 'a, 'b1 ) t -> ( 'a, 'b2 ) t

map_right f e is Right (f v) if e is Right v and e if e is Left _.

val map : left:( 'a1 -> 'a2 ) -> right:( 'b1 -> 'b2 ) -> ( 'a1, 'b1 ) t -> ( 'a2, 'b2 ) t

map ~left ~right (Left v) is Left (left v), map ~left ~right (Right v) is Right (right v).

val fold : left:( 'a -> 'c ) -> right:( 'b -> 'c ) -> ( 'a, 'b ) t -> 'c

fold ~left ~right (Left v) is left v, and fold ~left ~right (Right v) is right v.

val iter : left:( 'a -> unit ) -> right:( 'b -> unit ) -> ( 'a, 'b ) t -> unit

iter ~left ~right (Left v) is left v, and iter ~left ~right (Right v) is right v.

val for_all : left:( 'a -> bool ) -> right:( 'b -> bool ) -> ( 'a, 'b ) t -> bool

for_all ~left ~right (Left v) is left v, and for_all ~left ~right (Right v) is right v.

val equal : left:( 'a -> 'a -> bool ) -> right:( 'b -> 'b -> bool ) -> ( 'a, 'b ) t -> ( 'a, 'b ) t -> bool

equal ~left ~right e0 e1 tests equality of e0 and e1 using left and right to respectively compare values wrapped by Left _ and Right _.

val compare : left:( 'a -> 'a -> int ) -> right:( 'b -> 'b -> int ) -> ( 'a, 'b ) t -> ( 'a, 'b ) t -> int

compare ~left ~right e0 e1 totally orders e0 and e1 using left and right to respectively compare values wrapped by Left _ and Right _. Left _ values are smaller than Right _ values.