package batteries

The type of a non-empty doubly-linked list.

Creates a node. This is an O(1) operation.

Copy the list attached to the given node and return the copy of the given node. This is an O(N) operation.

Returns the length of the list. This is an O(N) operation.

List reversal. This is an O(N) operation. The given node still points to the same element, so to_list (rev (of_list [1;2;3;4])) = [1;4;3;2]

add n a Creates a new node containing data a and inserts it into the list after node n. This is an O(1) operation.

append n a Creates a new node containing data a and inserts it into the list after node n. Returns new node. This is an O(1) operation.

prepend n a Creates a new node containing data a and inserts it into the list before node n. Returns new node. This is an O(1) operation.

promote n Swaps n with next n. This is an O(1) operation.

demote n Swaps n with prev n. This is an O(1) operation.

Remove node from the list no matter where it is. This is an O(1) operation.

• raises Empty

  when trying to remove an element from a list of length one.

Remove node from the list no matter where it is. Return next node. This is an O(1) operation.

• raises Empty

  when trying to remove an element from a list of length one.

Remove node from the list no matter where it is. Return previous node. This is an O(1) operation.

• raises Empty

  when trying to remove an element from a list of length one.

splice n1 n2 Connects n1 and n2 so that next n1 == n2 && prev n2 == n1. This can be used to connect two discrete lists, or, if used on two nodes within the same list, it can be used to separate the nodes between n1 and n2 from the rest of the list. In this case, those nodes become a discrete list by themselves. This is an O(1) operation.

Given a node, get the data associated with that node. This is an O(1) operation.

Given a node, set the data associated with that node. This is an O(1) operation.

Given a node, get the next element in the list after the node.

The list is circular, so the last node of the list returns the first node of the list as it's next node.

This is an O(1) operation.

Given a node, get the previous element in the list before the node.

The list is circular, so the first node of the list returns the last element of the list as it's previous node.

This is an O(1) operation.

skip n i Return the node that is i nodes after node n in the list. If i is negative then return the node that is i nodes before node n in the list. This is an O(N) operation.

iter f n Apply f to every element in the list, starting at n. This is an O(N) operation.

Accumulate a value over the entire list. This works like List.fold_left. This is an O(N) operation.

Accumulate a value over the entire list. This works like List.fold_right, but since the list is bidirectional, it doesn't suffer the performance problems of List.fold_right. This is an O(N) operation.

find p l returns the first element, l or after, for which p returns true.

• raises Not_found

  if no such element exists @added 1.4.0

Test whether a given predicate returns true for all members of the given list. O(N)

Test whether there exists an element of the given list for which the predicate returns true. O(N)

Allocate a new list, with entirely new nodes, whose values are the transforms of the values of the original list. Note that this does not modify the given list. This is an O(N) operation.

filter p l returns a new list, with entirely new nodes, whose values are all the elements of the list l that satisfy the predicate p. The order of the elements in the input list is preserved.

• raises Empty

  if the resulting list is empty.

filter_map f l calls (f a0) (f a1) ... (f an) where a0,a1...an are the elements of l. It returns a new list of elements bi such as f ai = Some bi (when f returns None, the corresponding element of l is discarded).

• raises Empty

  if the resulting list is empty.

Converts a dllist to a normal list. This is an O(N) operation.

Converts from a normal list to a Dllist and returns the first node.

• raises Empty

  if given list is empty. This is an O(N) operation.

Create an enum of the list. Note that modifying the list while the enum exists will have undefined effects. This is an O(1) operation.

Create a reverse enum of the list. The enumeration starts with the current element of the list: rev_enum (of_list [1;2;3;4]) will generate the enumeration [1;4;3;2].

If you want it to start with the last one, see backwards.

Note that modifying the list while the enum exists will have undefined effects. This is an O(1) operation.

backwards t is similar to rev_enum t except that the enumeration starts at the node before the current one:

backwards (of_list [1;2;3;4]) will generate the enumeration [4;3;2;1].

Create a dllist from an enum. This consumes the enum, and allocates a whole new dllist.

• raises Empty

  if given enum is empty. This is an O(N) operation.