Module Lwt_sequence
module Lwt_sequence : sig..end
Mutable sequence of elements
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.
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 is_empty : 'a t -> bool
Returns true iff the given sequence is empty
val length : 'a t -> int
Returns the number of elemenets 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_l x s adds x to the right of the sequence s
exception Empty
Exception raised by take_l and tale_s 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_l 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_l 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_l f s applies f on all elements of s starting from the right
val iter_node_l : ('a node -> unit) -> 'a t -> unit
iter_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_l 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