dequeue Reference

Module defined in lua/common/dequeue.lua. Double-ended queue (deque) implementation supporting push/pop from both ends, rotation, removal, and iteration. Based on Pierre Chapuis's library.

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Exports

Functions

dequeue.new(data)

Creates a new deque, optionally from existing serialized data.

• Parameters:
  • data - table|nil - Optional table with existing data and head/tail indices for deserialization
• Returns: table - A deque object

Instance Methods

deque:push_right(x)

Pushes an element to the right (tail) end. Asserts x is not nil.

• Parameters: x - any (non-nil) - Element to push

deque:push_left(x)

Pushes an element to the left (head) end. Asserts x is not nil.

• Parameters: x - any (non-nil) - Element to push

deque:pop_right()

Removes and returns the rightmost element.

• Returns: any|nil - The element, or nil if empty

deque:pop_left()

Removes and returns the leftmost element.

• Returns: any|nil - The element, or nil if empty

deque:peek_right()

Returns the rightmost element without removing it.

• Returns: any|nil

deque:peek_left()

Returns the leftmost element without removing it.

• Returns: any|nil

deque:rotate_right(n)

Rotates the deque right by n positions (moves tail elements to head).

• Parameters: n - number|nil - Positions to rotate (default: 1)

deque:rotate_left(n)

Rotates the deque left by n positions (moves head elements to tail).

• Parameters: n - number|nil - Positions to rotate (default: 1)

deque:remove_right(x)

Removes the first occurrence of x searching from the right.

• Parameters: x - any - Value to find and remove
• Returns: boolean - True if found and removed

deque:remove_left(x)

Removes the first occurrence of x searching from the left.

• Parameters: x - any - Value to find and remove
• Returns: boolean - True if found and removed

deque:length()

• Returns: number - Number of elements

deque:is_empty()

• Returns: boolean - True if no elements

deque:contents()

• Returns: table - Array of all elements from left to right

deque:iter_right()

• Returns: function - Iterator yielding elements from right to left

deque:iter_left()

• Returns: function - Iterator yielding elements from left to right

deque:reset()

Empties the deque.

Internal Notes

• Internal representation uses head and tail indices - elements stored at integer keys in the table itself
• _serialize = true flag enables serialization support
• Supports deserialization: pass existing data table to new() to restore state