lwt 5.7.0 · OCaml Package

Mutable sequence of elements (deprecated)

A sequence is an object holding a list of elements which support the following operations:

adding an element to the left or the right in time and space O(1)
taking an element from the left or the right in time and space O(1)
removing a previously added element from a sequence in time and space O(1)
removing an element while the sequence is being transversed.

deprecated
This module should be an internal implementation detail of Lwt, and may be removed from the API at some point in the future. Use package lwt-dllist instead.

type 'a t

Type of a sequence holding values of type 'a

type 'a node

Type of a node holding one value of type 'a in a sequence

Operation on nodes

val get : 'a node -> 'a

Returns the contents of a node

val set : 'a node -> 'a -> unit

Change the contents of a node

val remove : 'a node -> unit

Removes a node from the sequence it is part of. It does nothing if the node has already been removed.

Operations on sequence

val create : unit -> 'a t

create () creates a new empty sequence

val clear : 'a t -> unit

Removes all nodes from the given sequence. The nodes are not actually mutated to note their removal. Only the sequence's pointers are updated.

val is_empty : 'a t -> bool

Returns true iff the given sequence is empty

val length : 'a t -> int

Returns the number of elements in the given sequence. This is a O(n) operation where n is the number of elements in the sequence.

val add_l : 'a -> 'a t -> 'a node

add_l x s adds x to the left of the sequence s

val add_r : 'a -> 'a t -> 'a node

add_r x s adds x to the right of the sequence s

exception Empty

Exception raised by take_l and take_r and when the sequence is empty

val take_l : 'a t -> 'a

take_l x s remove and returns the leftmost element of s

raises Empty
if the sequence is empty

val take_r : 'a t -> 'a

take_r x s remove and returns the rightmost element of s

raises Empty
if the sequence is empty

val take_opt_l : 'a t -> 'a option

take_opt_l x s remove and returns Some x where x is the leftmost element of s or None if s is empty

val take_opt_r : 'a t -> 'a option

take_opt_r x s remove and returns Some x where x is the rightmost element of s or None if s is empty

val transfer_l : 'a t -> 'a t -> unit

transfer_l s1 s2 removes all elements of s1 and add them at the left of s2. This operation runs in constant time and space.

val transfer_r : 'a t -> 'a t -> unit

transfer_r s1 s2 removes all elements of s1 and add them at the right of s2. This operation runs in constant time and space.

Sequence iterators

Note: it is OK to remove a node while traversing a sequence

val iter_l : ('a -> unit) -> 'a t -> unit

iter_l f s applies f on all elements of s starting from the left

val iter_r : ('a -> unit) -> 'a t -> unit

iter_r f s applies f on all elements of s starting from the right

val iter_node_l : ('a node -> unit) -> 'a t -> unit

iter_node_l f s applies f on all nodes of s starting from the left

val iter_node_r : ('a node -> unit) -> 'a t -> unit

iter_node_r f s applies f on all nodes of s starting from the right

val fold_l : ('a -> 'b -> 'b) -> 'a t -> 'b -> 'b

fold_l f s is:

fold_l f s x = f en (... (f e2 (f e1 x)))

where e1, e2, ..., en are the elements of s

val fold_r : ('a -> 'b -> 'b) -> 'a t -> 'b -> 'b

fold_r f s is:

fold_r f s x = f e1 (f e2 (... (f en x)))

where e1, e2, ..., en are the elements of s

val find_node_opt_l : ('a -> bool) -> 'a t -> 'a node option

find_node_opt_l f s returns Some x, where x is the first node of s starting from the left that satisfies f or None if none exists.

val find_node_opt_r : ('a -> bool) -> 'a t -> 'a node option

find_node_opt_r f s returns Some x, where x is the first node of s starting from the right that satisfies f or None if none exists.

val find_node_l : ('a -> bool) -> 'a t -> 'a node

find_node_l f s returns the first node of s starting from the left that satisfies f or raises Not_found if none exists.

val find_node_r : ('a -> bool) -> 'a t -> 'a node

find_node_r f s returns the first node of s starting from the right that satisfies f or raises Not_found if none exists.

package lwt

Operation on nodes

Operations on sequence

Sequence iterators