module Either: 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
let left: 'a => t('a, 'b);
left v is Left v.
let right: 'b => t('a, 'b);
right v is Right v.
let is_left: t('a, 'b) => bool;
is_left (Left v) is true, is_left (Right v) is false.
let is_right: t('a, 'b) => bool;
is_right (Left v) is false, is_right (Right v) is true.
let find_left: t('a, 'b) => option('a);
find_left (Left v) is Some v, find_left (Right _) is None
let find_right: t('a, 'b) => option('b);
find_right (Right v) is Some v, find_right (Left _) is None
let map_left: ('a1 => 'a2, t('a1, 'b)) => t('a2, 'b);
map_left f e is Left (f v) if e is Left v
and e if e is Right _.
let map_right: ('b1 => 'b2, t('a, 'b1)) => t('a, 'b2);
map_right f e is Right (f v) if e is Right v
and e if e is Left _.
let map: (~left: 'a1 => 'a2, ~right: 'b1 => 'b2, t('a1, 'b1)) => t('a2, 'b2);
map ~left ~right (Left v) is Left (left v),
map ~left ~right (Right v) is Right (right v).
let fold: (~left: 'a => 'c, ~right: 'b => 'c, t('a, 'b)) => 'c;
fold ~left ~right (Left v) is left v, and
fold ~left ~right (Right v) is right v.
let iter: (~left: 'a => unit, ~right: 'b => unit, t('a, 'b)) => unit;
iter ~left ~right (Left v) is left v, and
iter ~left ~right (Right v) is right v.
let for_all: (~left: 'a => bool, ~right: 'b => bool, t('a, 'b)) => bool;
for_all ~left ~right (Left v) is left v, and
for_all ~left ~right (Right v) is right v.
let equal:
(
~left: ('a, 'a) => bool,
~right: ('b, 'b) => bool,
t('a, 'b),
t('a, 'b)
) =>
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 _.
let compare:
(~left: ('a, 'a) => int, ~right: ('b, 'b) => int, t('a, 'b), t('a, 'b)) =>
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.