Module type Container_intf.S0
Signature for monomorphic container, e.g., string.
val length : t -> int
val is_empty : t -> bool
val iter : t -> f:(elt -> unit) -> unit
iter
must allow exceptions raised inf
to escape, terminating the iteration cleanly. The same holds for all functions below taking anf
.
val fold : t -> init:'accum -> f:('accum -> elt -> 'accum) -> 'accum
fold t ~init ~f
returnsf (... f (f (f init e1) e2) e3 ...) en
, wheree1..en
are the elements oft
.
val fold_result : t -> init:'accum -> f:('accum -> elt -> ('accum, 'e) Base.Result.t) -> ('accum, 'e) Base.Result.t
fold_result t ~init ~f
is a short-circuiting version offold
that runs in theResult
monad. Iff
returns anError _
, that value is returned without any additional invocations off
.
val fold_until : t -> init:'accum -> f:('accum -> elt -> ('accum, 'final) Continue_or_stop.t) -> finish:('accum -> 'final) -> 'final
fold_until t ~init ~f ~finish
is a short-circuiting version offold
. Iff
returnsStop _
the computation ceases and results in that value. Iff
returnsContinue _
, the fold will proceed. Iff
never returnsStop _
, the final result is computed byfinish
.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
val exists : t -> f:(elt -> bool) -> bool
Returns
true
if and only if there exists an element for which the provided function evaluates totrue
. This is a short-circuiting operation.
val for_all : t -> f:(elt -> bool) -> bool
Returns
true
if and only if the provided function evaluates totrue
for all elements. This is a short-circuiting operation.
val count : t -> f:(elt -> bool) -> int
Returns the number of elements for which the provided function evaluates to true.
val sum : (module Summable with type t = 'sum) -> t -> f:(elt -> 'sum) -> 'sum
Returns the sum of
f i
for alli
in the container.
val find : t -> f:(elt -> bool) -> elt option
Returns as an
option
the first element for whichf
evaluates to true.
val find_map : t -> f:(elt -> 'a option) -> 'a option
Returns the first evaluation of
f
that returnsSome
, and returnsNone
if there is no such element.
val to_list : t -> elt list
val to_array : t -> elt array
val min_elt : t -> compare:(elt -> elt -> int) -> elt option
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 usesfold
so it has the same complexity asfold
. ReturnsNone
iff the collection is empty.