'use strict'
module.exports = Yallist
Yallist.Node = Node
Yallist.create = Yallist
function Yallist (list) {
var self = this
if (!(self instanceof Yallist)) {
self = new Yallist()
}
self.tail = null
self.head = null
self.length = 0
if (list && typeof list.forEach === 'function') {
list.forEach(function (item) {
self.push(item)
})
} else if (arguments.length > 0) {
for (var i = 0, l = arguments.length; i < l; i++) {
self.push(arguments[i])
}
}
return self
}
Yallist.prototype.removeNode = function (node) {
if (node.list !== this) {
throw new Error('removing node which does not belong to this list')
}
var next = node.next
var prev = node.prev
if (next) {
next.prev = prev
}
if (prev) {
prev.next = next
}
if (node === this.head) {
this.head = next
}
if (node === this.tail) {
this.tail = prev
}
node.list.length--
node.next = null
node.prev = null
node.list = null
return next
}
Yallist.prototype.unshiftNode = function (node) {
if (node === this.head) {
return
}
if (node.list) {
node.list.removeNode(node)
}
var head = this.head
node.list = this
node.next = head
if (head) {
head.prev = node
}
this.head = node
if (!this.tail) {
this.tail = node
}
this.length++
}
Yallist.prototype.pushNode = function (node) {
if (node === this.tail) {
return
}
if (node.list) {
node.list.removeNode(node)
}
var tail = this.tail
node.list = this
node.prev = tail
if (tail) {
tail.next = node
}
this.tail = node
if (!this.head) {
this.head = node
}
this.length++
}
Yallist.prototype.push = function () {
for (var i = 0, l = arguments.length; i < l; i++) {
push(this, arguments[i])
}
return this.length
}
Yallist.prototype.unshift = function () {
for (var i = 0, l = arguments.length; i < l; i++) {
unshift(this, arguments[i])
}
return this.length
}
Yallist.prototype.pop = function () {
if (!this.tail) {
return undefined
}
var res = this.tail.value
this.tail = this.tail.prev
if (this.tail) {
this.tail.next = null
} else {
this.head = null
}
this.length--
return res
}
Yallist.prototype.shift = function () {
if (!this.head) {
return undefined
}
var res = this.head.value
this.head = this.head.next
if (this.head) {
this.head.prev = null
} else {
this.tail = null
}
this.length--
return res
}
Yallist.prototype.forEach = function (fn, thisp) {
thisp = thisp || this
for (var walker = this.head, i = 0; walker !== null; i++) {
fn.call(thisp, walker.value, i, this)
walker = walker.next
}
}
Yallist.prototype.forEachReverse = function (fn, thisp) {
thisp = thisp || this
for (var walker = this.tail, i = this.length - 1; walker !== null; i--) {
fn.call(thisp, walker.value, i, this)
walker = walker.prev
}
}
Yallist.prototype.get = function (n) {
for (var i = 0, walker = this.head; walker !== null && i < n; i++) {
// abort out of the list early if we hit a cycle
walker = walker.next
}
if (i === n && walker !== null) {
return walker.value
}
}
Yallist.prototype.getReverse = function (n) {
for (var i = 0, walker = this.tail; walker !== null && i < n; i++) {
// abort out of the list early if we hit a cycle
walker = walker.prev
}
if (i === n && walker !== null) {
return walker.value
}
}
Yallist.prototype.map = function (fn, thisp) {
thisp = thisp || this
var res = new Yallist()
for (var walker = this.head; walker !== null;) {
res.push(fn.call(thisp, walker.value, this))
walker = walker.next
}
return res
}
Yallist.prototype.mapReverse = function (fn, thisp) {
thisp = thisp || this
var res = new Yallist()
for (var walker = this.tail; walker !== null;) {
res.push(fn.call(thisp, walker.value, this))
walker = walker.prev
}
return res
}
Yallist.prototype.reduce = function (fn, initial) {
var acc
var walker = this.head
if (arguments.length > 1) {
acc = initial
} else if (this.head) {
walker = this.head.next
acc = this.head.value
} else {
throw new TypeError('Reduce of empty list with no initial value')
}
for (var i = 0; walker !== null; i++) {
acc = fn(acc, walker.value, i)
walker = walker.next
}
return acc
}
Yallist.prototype.reduceReverse = function (fn, initial) {
var acc
var walker = this.tail
if (arguments.length > 1) {
acc = initial
} else if (this.tail) {
walker = this.tail.prev
acc = this.tail.value
} else {
throw new TypeError('Reduce of empty list with no initial value')
}
for (var i = this.length - 1; walker !== null; i--) {
acc = fn(acc, walker.value, i)
walker = walker.prev
}
return acc
}
Yallist.prototype.toArray = function () {
var arr = new Array(this.length)
for (var i = 0, walker = this.head; walker !== null; i++) {
arr[i] = walker.value
walker = walker.next
}
return arr
}
Yallist.prototype.toArrayReverse = function () {
var arr = new Array(this.length)
for (var i = 0, walker = this.tail; walker !== null; i++) {
arr[i] = walker.value
walker = walker.prev
}
return arr
}
Yallist.prototype.slice = function (from, to) {
to = to || this.length
if (to < 0) {
to += this.length
}
from = from || 0
if (from < 0) {
from += this.length
}
var ret = new Yallist()
if (to < from || to < 0) {
return ret
}
if (from < 0) {
from = 0
}
if (to > this.length) {
to = this.length
}
for (var i = 0, walker = this.head; walker !== null && i < from; i++) {
walker = walker.next
}
for (; walker !== null && i < to; i++, walker = walker.next) {
ret.push(walker.value)
}
return ret
}
Yallist.prototype.sliceReverse = function (from, to) {
to = to || this.length
if (to < 0) {
to += this.length
}
from = from || 0
if (from < 0) {
from += this.length
}
var ret = new Yallist()
if (to < from || to < 0) {
return ret
}
if (from < 0) {
from = 0
}
if (to > this.length) {
to = this.length
}
for (var i = this.length, walker = this.tail; walker !== null && i > to; i--) {
walker = walker.prev
}
for (; walker !== null && i > from; i--, walker = walker.prev) {
ret.push(walker.value)
}
return ret
}
Yallist.prototype.splice = function (start, deleteCount, ...nodes) {
if (start > this.length) {
start = this.length - 1
}
if (start < 0) {
start = this.length + start;
}
for (var i = 0, walker = this.head; walker !== null && i < start; i++) {
walker = walker.next
}
var ret = []
for (var i = 0; walker && i < deleteCount; i++) {
ret.push(walker.value)
walker = this.removeNode(walker)
}
if (walker === null) {
walker = this.tail
}
if (walker !== this.head && walker !== this.tail) {
walker = walker.prev
}
for (var i = 0; i < nodes.length; i++) {
walker = insert(this, walker, nodes[i])
}
return ret;
}
Yallist.prototype.reverse = function () {
var head = this.head
var tail = this.tail
for (var walker = head; walker !== null; walker = walker.prev) {
var p = walker.prev
walker.prev = walker.next
walker.next = p
}
this.head = tail
this.tail = head
return this
}
function insert (self, node, value) {
var inserted = node === self.head ?
new Node(value, null, node, self) :
new Node(value, node, node.next, self)
if (inserted.next === null) {
self.tail = inserted
}
if (inserted.prev === null) {
self.head = inserted
}
self.length++
return inserted
}
function push (self, item) {
self.tail = new Node(item, self.tail, null, self)
if (!self.head) {
self.head = self.tail
}
self.length++
}
function unshift (self, item) {
self.head = new Node(item, null, self.head, self)
if (!self.tail) {
self.tail = self.head
}
self.length++
}
function Node (value, prev, next, list) {
if (!(this instanceof Node)) {
return new Node(value, prev, next, list)
}
this.list = list
this.value = value
if (prev) {
prev.next = this
this.prev = prev
} else {
this.prev = null
}
if (next) {
next.prev = this
this.next = next
} else {
this.next = null
}
}
try {
// add if support for Symbol.iterator is present
require('./iterator.js')(Yallist)
} catch (er) {}