Module `CCRAL`

Random-Access Lists

This is an OCaml implementation of Okasaki's paper "Purely Functional Random Access Lists". It defines a list-like data structure with O(1) cons/tail operations, and O(log(n)) lookup/modification operations.

This module used to be part of containers.misc

status: stable

since: 0.13

type +'a t: List containing elements of type 'a

val empty : 'a t: Empty list.

val is_empty : _ t -> bool: Check whether the list is empty.

val cons : 'a -> 'a t -> 'a t: Add an element at the front of the list.

val return : 'a -> 'a t: Singleton.

val map : f:('a -> 'b) -> 'a t -> 'b t: Map on elements.

val mapi : f:(int -> 'a -> 'b) -> 'a t -> 'b t: Map with index.

val hd : 'a t -> 'a

First element of the list, or

raises Invalid_argument: if the list is empty.

val tl : 'a t -> 'a t

Remove the first element from the list, or

raises Invalid_argument: if the list is empty.

val front : 'a t -> ('a * 'a t) option: Remove and return the first element of the list.

val front_exn : 'a t -> 'a * 'a t

Unsafe version of front.

raises Invalid_argument: if the list is empty.

val length : 'a t -> int: Number of elements. Complexity O(ln n) where n=number of elements.

val get : 'a t -> int -> 'a option: get l i accesses the i-th element of the list. O(log(n)).

val get_exn : 'a t -> int -> 'a

Unsafe version of get.

raises Invalid_argument: if the list has less than i+1 elements.

val set : 'a t -> int -> 'a -> 'a t

set l i v sets the i-th element of the list to v. O(log(n)).

raises Invalid_argument: if the list has less than i+1 elements.

val remove : 'a t -> int -> 'a t

remove l i removes the i-th element of v.

raises Invalid_argument: if the list has less than i+1 elements.

val append : 'a t -> 'a t -> 'a t
val filter : f:('a -> bool) -> 'a t -> 'a t
val filter_map : f:('a -> 'b option) -> 'a t -> 'b t
val flat_map : ('a -> 'b t) -> 'a t -> 'b t
val flatten : 'a t t -> 'a t
val app : ('a -> 'b) t -> 'a t -> 'b t
val take : int -> 'a t -> 'a t
val take_while : f:('a -> bool) -> 'a t -> 'a t
val drop : int -> 'a t -> 'a t
val drop_while : f:('a -> bool) -> 'a t -> 'a t
val take_drop : int -> 'a t -> 'a t * 'a t: take_drop n l splits l into a, b such that length a = n if length l >= n, and such that append a b = l.

val iter : f:('a -> unit) -> 'a t -> unit: Iterate on the list's elements.

val iteri : f:(int -> 'a -> unit) -> 'a t -> unit
val fold : f:('b -> 'a -> 'b) -> x:'b -> 'a t -> 'b: Fold on the list's elements.

val fold_rev : f:('b -> 'a -> 'b) -> x:'b -> 'a t -> 'b: Fold on the list's elements, in reverse order (starting from the tail).

val rev_map : f:('a -> 'b) -> 'a t -> 'b t: rev_map f l is the same as map f (rev l).

val rev : 'a t -> 'a t: Reverse the list.

val equal : eq:('a -> 'a -> bool) -> 'a t -> 'a t -> bool
val compare : cmp:('a -> 'a -> int) -> 'a t -> 'a t -> int: Lexicographic comparison.

Utils

val make : int -> 'a -> 'a t
val repeat : int -> 'a t -> 'a t: repeat n l is append l (append l ... l) n times.

val range : int -> int -> int t: range i j is i; i+1; ... ; j or j; j-1; ...; i.

Conversions

type 'a iter = ('a -> unit) -> unit
type 'a gen = unit -> 'a option

val add_list : 'a t -> 'a list -> 'a t
val of_list : 'a list -> 'a t: Convert a list to a RAL. Caution: non tail-rec.

val to_list : 'a t -> 'a list
val of_list_map : f:('a -> 'b) -> 'a list -> 'b t: Combination of of_list and map.

val of_array : 'a array -> 'a t
val add_array : 'a t -> 'a array -> 'a t
val to_array : 'a t -> 'a array: More efficient than on usual lists.

val add_iter : 'a t -> 'a iter -> 'a t
val of_iter : 'a iter -> 'a t
val to_iter : 'a t -> 'a iter
val add_gen : 'a t -> 'a gen -> 'a t
val of_gen : 'a gen -> 'a t
val to_gen : 'a t -> 'a gen

Infix

module Infix : sig ... end

include module type of Infix

val (@+) : 'a -> 'a t -> 'a t: Cons (alias to cons).

val (>>=) : 'a t -> ('a -> 'b t) -> 'b t: Alias to flat_map.

val (>|=) : 'a t -> ('a -> 'b) -> 'b t: Alias to map.

val (<*>) : ('a -> 'b) t -> 'a t -> 'b t: Alias to app.

val (--) : int -> int -> int t: Alias to range.

val (--^) : int -> int -> int t

a --^ b is the integer range from a to b, where b is excluded.

since: 0.17

IO

type 'a printer = Stdlib.Format.formatter -> 'a -> unit

val pp : ?⁠pp_sep:unit printer -> 'a printer -> 'a t printer