Container.S0_phantominclude sig ... endval length : 'a 'p1 'p2. 'p1 t -> intval is_empty : 'a 'p1 'p2. 'p1 t -> booliter must allow exceptions raised in f to escape, terminating the iteration cleanly. The same holds for all functions below taking an f.
Returns true if and only if there exists an element for which the provided function evaluates to true. This is a short-circuiting operation.
Returns true if and only if the provided function evaluates to true for all elements. This is a short-circuiting operation.
Returns the number of elements for which the provided function evaluates to true.
Returns as an option the first element for which f evaluates to true.
Returns a min (resp. max) element from the collection using the provided compare function. In case of a tie, the first element encountered while traversing the collection is returned. The implementation uses fold so it has the same complexity as fold. Returns None iff the collection is empty.
val sum :
'a 'sum 'p1 'p2. (module Summable with type t = 'sum) ->
'p1 t ->
f:(elt -> 'sum) @ local ->
'sumReturns the sum of f i for all i in the container. The order in which the elements will be summed is unspecified.
val iter_until :
'a 'p1 'p2 'final. 'p1 t ->
f:(elt -> (unit, 'final) Continue_or_stop.t) @ local ->
(finish:(unit -> 'final) @ local ->
'final) @ localiter_until t ~f ~finish is a short-circuiting version of iter. If f returns Stop x the computation ceases and returns x. If f always returns Continue () the final result is computed by finish.
fold t ~init ~f returns f (... f (f (f init e1) e2) e3 ...) en, where e1..en are the elements of t.
val fold_result :
'a 'p1 'p2 'acc 'e. 'p1 t ->
init:'acc ->
f:('acc -> (elt -> ('acc, 'e) Result.t) @ local) @ local ->
('acc, 'e) Result.tfold_result t ~init ~f is a short-circuiting version of fold that runs in the Result monad. If f returns an Error _, that value is returned without any additional invocations of f.
Returns the first evaluation of f that returns Some, and returns None if there is no such element.
val fold_until :
'a 'p1 'p2 'acc 'final. 'p1 t ->
init:'acc ->
f:('acc -> (elt -> ('acc, 'final) Continue_or_stop.t) @ local) @ local ->
(finish:('acc -> 'final) @ local ->
'final) @ localfold_until t ~init ~f ~finish is a short-circuiting version of fold. If f returns Stop _ the computation ceases and results in that value. If f returns Continue _, the fold will proceed. If f never returns Stop _, the final result is computed by finish.
Example:
type maybe_negative =
| Found_negative of int
| All_nonnegative of { sum : int }
(** [first_neg_or_sum list] returns the first negative number in [list], if any,
otherwise returns the sum of the list. *)
let first_neg_or_sum =
List.fold_until ~init:0
~f:(fun sum x ->
if x < 0
then Stop (Found_negative x)
else Continue (sum + x))
~finish:(fun sum -> All_nonnegative { sum })
;;
let x = first_neg_or_sum [1; 2; 3; 4; 5]
val x : maybe_negative = All_nonnegative {sum = 15}
let y = first_neg_or_sum [1; 2; -3; 4; 5]
val y : maybe_negative = Found_negative -3