package base
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base
-
-
base.base_internalhash_types
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base.caml
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base.md5
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base.shadow_stdlib
Library
Module
Module type
Parameter
Class
Class type
The idiom for using Container.Make
is to bind the resulting module and to explicitly import each of the functions that one wants:
module C = Container.Make (struct ... end)
let count = C.count
let exists = C.exists
let find = C.find
(* ... *)
This is preferable to:
include Container.Make (struct ... end)
because the include
makes it too easy to shadow specialized implementations of container functions (length
being a common one).
Container.Make0
is like Container.Make
, but for monomorphic containers like string
.
Parameters
module T : sig ... end
Signature
val mem : 'a T.t -> 'a -> equal:('a -> 'a -> bool) -> bool
Checks whether the provided element is there, using equal
.
val length : 'a T.t -> int
val is_empty : 'a T.t -> bool
val iter : 'a T.t -> f:('a -> unit) -> unit
val fold : 'a T.t -> init:'accum -> f:('accum -> 'a -> 'accum) -> 'accum
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 T.t ->
init:'accum ->
f:('accum -> 'a -> ('accum, 'e) Result.t) ->
('accum, 'e) Result.t
fold_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
.
val fold_until :
'a T.t ->
init:'accum ->
f:('accum -> 'a -> ('accum, 'final) Continue_or_stop.t) ->
finish:('accum -> 'final) ->
'final
fold_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
val exists : 'a T.t -> f:('a -> bool) -> bool
Returns true
if and only if there exists an element for which the provided function evaluates to true
. This is a short-circuiting operation.
val for_all : 'a T.t -> f:('a -> bool) -> bool
Returns true
if and only if the provided function evaluates to true
for all elements. This is a short-circuiting operation.
val count : 'a T.t -> f:('a -> bool) -> int
Returns the number of elements for which the provided function evaluates to true.
Returns the sum of f i
for all i
in the container.
val find : 'a T.t -> f:('a -> bool) -> 'a option
Returns as an option
the first element for which f
evaluates to true.
val find_map : 'a T.t -> f:('a -> 'b option) -> 'b option
Returns the first evaluation of f
that returns Some
, and returns None
if there is no such element.
val to_list : 'a T.t -> 'a list
val to_array : 'a T.t -> 'a array
val min_elt : 'a T.t -> compare:('a -> 'a -> int) -> 'a option
Returns a minimum (resp maximum) element from the collection using the provided compare
function, or None
if the collection is empty. 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
.
val max_elt : 'a T.t -> compare:('a -> 'a -> int) -> 'a option