[jass]library DoublyLinkedList
module DoublyLinkedList
readonly thistype head

private thistype _first
method operator first takes nothing returns thistype
return this.head._first
endmethod

private thistype _last
method operator last takes nothing returns thistype
return this.head._last
endmethod

readonly thistype prev
readonly thistype next

private integer _count
method operator count takes nothing returns integer
return this.head._count
endmethod

static method createNode takes nothing returns thistype
local thistype this = thistype.allocate()

set this.head = 0

set this._first = 0
set this._last = 0

set this.prev = this
set this.next = this

set this._count = 0

return this
endmethod

static method createHead takes nothing returns thistype
local thistype this = thistype.createNode()
set this.head = this
return this
endmethod

method insertNode takes thistype node returns boolean
// Evitamos insertar si la instancia no es head
if ( this != this.head ) then
return false
endif

set node.head = this
set node.next = this

if ( this._first == 0 ) then
set this._first = node
endif

if ( this._last != 0 ) then
set node.prev = this._last
set this._last.next = node
endif

set this._last = node

set this._count = this._count + 1

return false
endmethod

method removeNode takes nothing returns boolean
local thistype head = this.head

if ( head == 0 ) then
return false
endif

if ( this == head ) then
return false
endif

if ( head._first == this ) then
set head._first = this.next
endif

if ( head._last == this ) then
set head._last = this.prev
endif

set this.prev.next = this.next
set this.next.prev = this.prev

set head._count = head._count - 1

call this.deallocate()

return true
endmethod

/**
* Removemos y destruimos todos los nodos de la lista
*/
method clearList takes nothing returns nothing
local thistype node

if ( this != this.head ) then
return
endif

loop
set node = this._first
exitwhen node == 0

call node.deallocate()
endloop

set this._first = 0
set this._last = 0

set this._count = 0
endmethod
endmodule
endlibrary[/jass]