OCaml library : Stdlib.Either (original) (raw)

Module Stdlib.Either

module Either: [Either](Either.html)

type ('a, 'b) t = 

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

val left : 'a -> ('a, 'b) [t](Either.html#TYPEt)

val right : 'b -> ('a, 'b) [t](Either.html#TYPEt)

val is_left : ('a, 'b) [t](Either.html#TYPEt) -> bool

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

val is_right : ('a, 'b) [t](Either.html#TYPEt) -> bool

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

val find_left : ('a, 'b) [t](Either.html#TYPEt) -> 'a option

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

val find_right : ('a, 'b) [t](Either.html#TYPEt) -> 'b option

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

val map_left : ('a1 -> 'a2) -> ('a1, 'b) [t](Either.html#TYPEt) -> ('a2, 'b) [t](Either.html#TYPEt)

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](Either.html#TYPEt) -> ('a, 'b2) [t](Either.html#TYPEt)

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](Either.html#TYPEt) -> ('a2, 'b2) [t](Either.html#TYPEt)

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](Either.html#TYPEt) -> 'c

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

val iter : left:('a -> unit) -> right:('b -> unit) -> ('a, 'b) [t](Either.html#TYPEt) -> unit

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

val for_all : left:('a -> bool) -> right:('b -> bool) -> ('a, 'b) [t](Either.html#TYPEt) -> bool

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

val equal : left:('a -> 'a -> bool) -> right:('b -> 'b -> bool) -> ('a, 'b) [t](Either.html#TYPEt) -> ('a, 'b) [t](Either.html#TYPEt) -> bool

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

val compare : left:('a -> 'a -> int) -> right:('b -> 'b -> int) -> ('a, 'b) [t](Either.html#TYPEt) -> ('a, 'b) [t](Either.html#TYPEt) -> int

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