ocaml-containers/src/core/CCList.mli
2016-02-23 15:34:26 +01:00

474 lines
14 KiB
OCaml

(* This file is free software, part of containers. See file "license" for more details. *)
(** {1 complements to list} *)
type 'a t = 'a list
val empty : 'a t
val is_empty : _ t -> bool
(** [is_empty l] returns [true] iff [l = []]
@since 0.11 *)
val map : ('a -> 'b) -> 'a t -> 'b t
(** Safe version of map *)
val (>|=) : 'a t -> ('a -> 'b) -> 'b t
(** Infix version of [map] with reversed arguments
@since 0.5 *)
val cons : 'a -> 'a t -> 'a t
(** [cons x l] is [x::l]
@since 0.12 *)
val append : 'a t -> 'a t -> 'a t
(** Safe version of append *)
val cons_maybe : 'a option -> 'a t -> 'a t
(** [cons_maybe (Some x) l] is [x :: l]
[cons_maybe None l] is [l]
@since 0.13 *)
val (@) : 'a t -> 'a t -> 'a t
val filter : ('a -> bool) -> 'a t -> 'a t
(** Safe version of {!List.filter} *)
val fold_right : ('a -> 'b -> 'b) -> 'a t -> 'b -> 'b
(** Safe version of [fold_right] *)
val fold_while : ('a -> 'b -> 'a * [`Stop | `Continue]) -> 'a -> 'b t -> 'a
(** Fold until a stop condition via [('a, `Stop)] is
indicated by the accumulator
@since 0.8 *)
val fold_map : ('acc -> 'a -> 'acc * 'b) -> 'acc -> 'a list -> 'acc * 'b list
(** [fold_map f acc l] is a [fold_left]-like function, but it also maps the
list to another list.
@since 0.14 *)
val fold_map2 : ('acc -> 'a -> 'b -> 'acc * 'c) -> 'acc -> 'a list -> 'b list -> 'acc * 'c list
(** [fold_map2] is to [fold_map] what [List.map2] is to [List.map].
@raise Invalid_argument if the lists do not have the same length
@since NEXT_RELEASE *)
val fold_flat_map : ('acc -> 'a -> 'acc * 'b list) -> 'acc -> 'a list -> 'acc * 'b list
(** [fold_flat_map f acc l] is a [fold_left]-like function, but it also maps the
list to a list of lists that is then [flatten]'d..
@since 0.14 *)
val init : int -> (int -> 'a) -> 'a t
(** Similar to {!Array.init}
@since 0.6 *)
val compare : ('a -> 'a -> int) -> 'a t -> 'a t -> int
val equal : ('a -> 'a -> bool) -> 'a t -> 'a t -> bool
val flat_map : ('a -> 'b t) -> 'a t -> 'b t
(** Map and flatten at the same time (safe). Evaluation order is not guaranteed. *)
val flatten : 'a t t -> 'a t
(** Safe flatten *)
val product : ('a -> 'b -> 'c) -> 'a t -> 'b t -> 'c t
(** Cartesian product of the two lists, with the given combinator *)
val fold_product : ('c -> 'a -> 'b -> 'c) -> 'c -> 'a t -> 'b t -> 'c
(** Fold on the cartesian product *)
val diagonal : 'a t -> ('a * 'a) t
(** All pairs of distinct positions of the list. [list_diagonal l] will
return the list of [List.nth i l, List.nth j l] if [i < j]. *)
val partition_map : ('a -> [<`Left of 'b | `Right of 'c | `Drop]) ->
'a list -> 'b list * 'c list
(** [partition_map f l] maps [f] on [l] and gather results in lists:
- if [f x = `Left y], adds [y] to the first list
- if [f x = `Right z], adds [z] to the second list
- if [f x = `Drop], ignores [x]
@since 0.11 *)
val pure : 'a -> 'a t
val (<*>) : ('a -> 'b) t -> 'a t -> 'b t
val (<$>) : ('a -> 'b) -> 'a t -> 'b t
val return : 'a -> 'a t
val (>>=) : 'a t -> ('a -> 'b t) -> 'b t
val take : int -> 'a t -> 'a t
(** Take the [n] first elements, drop the rest *)
val drop : int -> 'a t -> 'a t
(** Drop the [n] first elements, keep the rest *)
val hd_tl : 'a t -> 'a * 'a t
(** [hd_tl (x :: l)] returns [hd, l].
@raise Failure if the list is empty
@since NEXT_RELEASE *)
val take_drop : int -> 'a t -> 'a t * 'a t
(** [take_drop n l] returns [l1, l2] such that [l1 @ l2 = l] and
[length l1 = min (length l) n] *)
val take_while : ('a -> bool) -> 'a t -> 'a t
(** @since 0.13 *)
val drop_while : ('a -> bool) -> 'a t -> 'a t
(** @since 0.13 *)
val split : int -> 'a t -> 'a t * 'a t
(** Synonym to {!take_drop}
@deprecated since 0.13: conflict with the {!List.split} standard function *)
val last : int -> 'a t -> 'a t
(** [last n l] takes the last [n] elements of [l] (or less if
[l] doesn't have that many elements *)
val find_pred : ('a -> bool) -> 'a t -> 'a option
(** [find_pred p l] finds the first element of [l] that satisfies [p],
or returns [None] if no element satisfies [p]
@since 0.11 *)
val find_pred_exn : ('a -> bool) -> 'a t -> 'a
(** Unsafe version of {!find_pred}
@raise Not_found if no such element is found
@since 0.11 *)
val find_map : ('a -> 'b option) -> 'a t -> 'b option
(** [find_map f l] traverses [l], applying [f] to each element. If for
some element [x], [f x = Some y], then [Some y] is returned. Otherwise
the call returns [None]
@since 0.11 *)
val find : ('a -> 'b option) -> 'a list -> 'b option
(** @deprecated since 0.11 in favor of {!find_map}, for the name is too confusing *)
val find_mapi : (int -> 'a -> 'b option) -> 'a t -> 'b option
(** Like {!find_map}, but also pass the index to the predicate function.
@since 0.11 *)
val findi : (int -> 'a -> 'b option) -> 'a t -> 'b option
(** @deprecated since 0.11 in favor of {!find_mapi}, name is too confusing
@since 0.3.4 *)
val find_idx : ('a -> bool) -> 'a t -> (int * 'a) option
(** [find_idx p x] returns [Some (i,x)] where [x] is the [i]-th element of [l],
and [p x] holds. Otherwise returns [None] *)
val remove : ?eq:('a -> 'a -> bool) -> x:'a -> 'a t -> 'a t
(** [remove ~x l] removes every instance of [x] from [l]. Tailrec.
@param eq equality function
@since 0.11 *)
val filter_map : ('a -> 'b option) -> 'a t -> 'b t
(** Map and remove elements at the same time *)
val sorted_merge : ?cmp:('a -> 'a -> int) -> 'a list -> 'a list -> 'a list
(** Merges elements from both sorted list *)
val sort_uniq : ?cmp:('a -> 'a -> int) -> 'a list -> 'a list
(** Sort the list and remove duplicate elements *)
val sorted_merge_uniq : ?cmp:('a -> 'a -> int) -> 'a list -> 'a list -> 'a list
(** [sorted_merge_uniq l1 l2] merges the sorted lists [l1] and [l2] and
removes duplicates
@since 0.10 *)
val uniq_succ : ?eq:('a -> 'a -> bool) -> 'a list -> 'a list
(** [uniq_succ l] removes duplicate elements that occur one next to the other.
Examples:
[uniq_succ [1;2;1] = [1;2;1]]
[uniq_succ [1;1;2] = [1;2]]
@since 0.10 *)
val group_succ : ?eq:('a -> 'a -> bool) -> 'a list -> 'a list list
(** [group_succ ~eq l] groups together consecutive elements that are equal
according to [eq]
@since 0.11 *)
(** {2 Indices} *)
module Idx : sig
val mapi : (int -> 'a -> 'b) -> 'a t -> 'b t
val iteri : (int -> 'a -> unit) -> 'a t -> unit
val foldi : ('b -> int -> 'a -> 'b) -> 'b -> 'a t -> 'b
(** Fold on list, with index *)
val get : 'a t -> int -> 'a option
val get_exn : 'a t -> int -> 'a
(** Get the i-th element, or
@raise Not_found if the index is invalid *)
val set : 'a t -> int -> 'a -> 'a t
(** Set i-th element (removes the old one), or does nothing if
index is too high *)
val insert : 'a t -> int -> 'a -> 'a t
(** Insert at i-th position, between the two existing elements. If the
index is too high, append at the end of the list *)
val remove : 'a t -> int -> 'a t
(** Remove element at given index. Does nothing if the index is
too high. *)
end
(** {2 Set Operators} *)
module Set : sig
val add : ?eq:('a -> 'a -> bool) -> 'a -> 'a t -> 'a t
(** [add x set] adds [x] to [set] if it was not already present. Linear time.
@since 0.11 *)
val remove : ?eq:('a -> 'a -> bool) -> 'a -> 'a t -> 'a t
(** [remove x set] removes one occurrence of [x] from [set]. Linear time.
@since 0.11 *)
val mem : ?eq:('a -> 'a -> bool) -> 'a -> 'a t -> bool
(** Membership to the list. Linear time *)
val subset : ?eq:('a -> 'a -> bool) -> 'a t -> 'a t -> bool
(** Test for inclusion *)
val uniq : ?eq:('a -> 'a -> bool) -> 'a t -> 'a t
(** List uniq. Remove duplicates w.r.t the equality predicate.
Complexity is quadratic in the length of the list, but the order
of elements is preserved. If you wish for a faster de-duplication
but do not care about the order, use {!sort_uniq}*)
val union : ?eq:('a -> 'a -> bool) -> 'a t -> 'a t -> 'a t
(** List union. Complexity is product of length of inputs. *)
val inter : ?eq:('a -> 'a -> bool) -> 'a t -> 'a t -> 'a t
(** List intersection. Complexity is product of length of inputs. *)
end
(** {2 Other Constructors} *)
val range : int -> int -> int t
(** [range i j] iterates on integers from [i] to [j] included . It works
both for decreasing and increasing ranges *)
val range' : int -> int -> int t
(** Same as {!range} but the second bound is excluded.
For instance [range' 0 5 = [0;1;2;3;4]] *)
val (--) : int -> int -> int t
(** Infix alias for [range] *)
val replicate : int -> 'a -> 'a t
(** Replicate the given element [n] times *)
val repeat : int -> 'a t -> 'a t
(** Concatenate the list with itself [n] times *)
(** {2 Association Lists} *)
module Assoc : sig
type ('a, 'b) t = ('a*'b) list
val get : ?eq:('a->'a->bool) -> ('a,'b) t -> 'a -> 'b option
(** Find the element *)
val get_exn : ?eq:('a->'a->bool) -> ('a,'b) t -> 'a -> 'b
(** Same as [get]
@raise Not_found if the element is not present *)
val set : ?eq:('a->'a->bool) -> ('a,'b) t -> 'a -> 'b -> ('a,'b) t
(** Add the binding into the list (erase it if already present) *)
val mem : ?eq:('a->'a->bool) -> ('a,_) t -> 'a -> bool
(** [mem l x] returns [true] iff [x] is a key in [l]
@since NEXT_RELEASE *)
val update :
?eq:('a->'a->bool) -> ('a,'b) t -> 'a -> f:('b option -> 'b option) -> ('a,'b) t
(** [update l k ~f] updates [l] on the key [k], by calling [f (get l k)]
and removing [k] if it returns [None], mapping [k] to [v'] if it
returns [Some v']
@since NEXT_RELEASE *)
end
(** {2 Zipper} *)
module Zipper : sig
type 'a t = 'a list * 'a list
(** The pair [l, r] represents the list [List.rev_append l r], but
with the focus on [r]. *)
val empty : 'a t
(** Empty zipper *)
val is_empty : _ t -> bool
(** Empty zipper? Returns true iff the two lists are empty. *)
(*$T
Zipper.(is_empty empty)
not ([42] |> Zipper.make |> Zipper.right |> Zipper.is_empty)
*)
val to_list : 'a t -> 'a list
(** Convert the zipper back to a list.
[to_list (l,r)] is [List.rev_append l r] *)
val to_rev_list : 'a t -> 'a list
(** Convert the zipper back to a {i reversed} list.
In other words, [to_list (l,r)] is [List.rev_append r l]
@since 0.14 *)
val make : 'a list -> 'a t
(** Create a zipper pointing at the first element of the list *)
val left : 'a t -> 'a t
(** Go to the left, or do nothing if the zipper is already at leftmost pos *)
val left_exn : 'a t -> 'a t
(** Go to the left, or
@raise Invalid_argument if the zipper is already at leftmost pos
@since 0.14 *)
val right : 'a t -> 'a t
(** Go to the right, or do nothing if the zipper is already at rightmost pos *)
val right_exn : 'a t -> 'a t
(** Go to the right, or
@raise Invalid_argument if the zipper is already at rightmost pos
@since 0.14 *)
val modify : ('a option -> 'a option) -> 'a t -> 'a t
(** Modify the current element, if any, by returning a new element, or
returning [None] if the element is to be deleted *)
val insert : 'a -> 'a t -> 'a t
(** Insert an element at the current position. If an element was focused,
[insert x l] adds [x] just before it, and focuses on [x]
@since 0.14 *)
val remove : 'a t -> 'a t
(** [remove l] removes the current element, if any.
@since 0.14 *)
val is_focused : _ t -> bool
(** Is the zipper focused on some element? That is, will {!focused}
return a [Some v]?
@since 0.14 *)
val focused : 'a t -> 'a option
(** Returns the focused element, if any. [focused zip = Some _] iff
[empty zip = false] *)
val focused_exn : 'a t -> 'a
(** Returns the focused element, or
@raise Not_found if the zipper is at an end *)
val drop_before : 'a t -> 'a t
(** Drop every element on the "left" (calling {!left} then will do nothing).
@since 0.14 *)
val drop_after : 'a t -> 'a t
(** Drop every element on the "right" (calling {!right} then will do nothing),
keeping the focused element, if any.
@since 0.14 *)
val drop_after_and_focused : 'a t -> 'a t
(** Drop every element on the "right" (calling {!right} then will do nothing),
{i including} the focused element if it is present.
@since 0.14 *)
(*$=
([1], [2]) (Zipper.drop_after ([1], [2;3]))
([1], []) (Zipper.drop_after ([1], []))
([1], []) (Zipper.drop_after_and_focused ([1], [2;3]))
*)
end
(** {2 References on Lists}
@since 0.3.3 *)
module Ref : sig
type 'a t = 'a list ref
val push : 'a t -> 'a -> unit
val pop : 'a t -> 'a option
val pop_exn : 'a t -> 'a
(** Unsafe version of {!pop}.
@raise Failure if the list is empty *)
val create : unit -> 'a t
(** Create a new list reference *)
val clear : _ t -> unit
(** Remove all elements *)
val lift : ('a list -> 'b) -> 'a t -> 'b
(** Apply a list function to the content *)
val push_list : 'a t -> 'a list -> unit
(** Add elements of the list at the beginning of the list ref. Elements
at the end of the list will be at the beginning of the list ref *)
end
(** {2 Monadic Operations} *)
module type MONAD = sig
type 'a t
val return : 'a -> 'a t
val (>>=) : 'a t -> ('a -> 'b t) -> 'b t
end
module Traverse(M : MONAD) : sig
val sequence_m : 'a M.t t -> 'a t M.t
val fold_m : ('b -> 'a -> 'b M.t) -> 'b -> 'a t -> 'b M.t
val map_m : ('a -> 'b M.t) -> 'a t -> 'b t M.t
val map_m_par : ('a -> 'b M.t) -> 'a t -> 'b t M.t
(** Same as {!map_m} but [map_m_par f (x::l)] evaluates [f x] and
[f l] "in parallel" before combining their result (for instance
in Lwt). *)
end
(** {2 Conversions} *)
type 'a sequence = ('a -> unit) -> unit
type 'a gen = unit -> 'a option
type 'a klist = unit -> [`Nil | `Cons of 'a * 'a klist]
type 'a printer = Buffer.t -> 'a -> unit
type 'a formatter = Format.formatter -> 'a -> unit
type 'a random_gen = Random.State.t -> 'a
val random : 'a random_gen -> 'a t random_gen
val random_non_empty : 'a random_gen -> 'a t random_gen
val random_len : int -> 'a random_gen -> 'a t random_gen
val random_choose : 'a t -> 'a random_gen
(** Randomly choose an element in the list.
@raise Not_found if the list is empty *)
val random_sequence : 'a random_gen t -> 'a t random_gen
val to_seq : 'a t -> 'a sequence
val of_seq : 'a sequence -> 'a t
val to_gen : 'a t -> 'a gen
val of_gen : 'a gen -> 'a t
val to_klist : 'a t -> 'a klist
val of_klist : 'a klist -> 'a t
(** {2 IO} *)
val pp : ?start:string -> ?stop:string -> ?sep:string ->
'a printer -> 'a t printer
val print : ?start:string -> ?stop:string -> ?sep:string ->
'a formatter -> 'a t formatter