fifo

fifo

FIFO queue implemented using a double linked-list

npm install fifo

Usage

var fifo = require('fifo')()

fifo.push('hello')
fifo.push('world')

console.log(fifo.first()) // prints hello
console.log(fifo.last())  // prints world

console.log(fifo.shift()) // prints hello
console.log(fifo.shift()) // prints world

var node = fifo.push('meh')

fifo.remove(node)     // remove 'meh' from the stack
fifo.unshift('hello') // insert at the beginning

fifo uses a linked list behind the scene so all list manipulation methods run in O(1)

API

fifo = FIFO()

Create a new instance

fifo.node

Contains the first node on the list.

fifo.length

Number of nodes in the list.

node = fifo.push(value)

Push a new value to the end of the list. Returns a node that contains this value. The value can be accessed by accessing node.value.

value = fifo.shift()

Removes the first node and returns the value

value = fifo.pop()

Removes the last node and returns the value

value = fifo.remove(node)

Removes the node and returns the value

fifo.add(node)

Readds a node. Should only be done with a node that has been removed.

value = fifo.first()

Peek at the first value

value = fifo.last()

Peek at the last value

node = fifo.unshift(value)

Inserts a value at the beginning of the list

node = fifo.next(node)

Returns the next node relative to the node you pass. If the node was the last node in the list null is returned.

node = fifo.prev(node)

Returns the previous node relative to the node you pass. If the node was the first node in the list null is returned.

fifo.bump(node)

Moves a node to the end of the list

fifo.clear()

Clears the list.

fifo.forEach(fn)

Iterate over all values in the list. Calls the function with value, node.

Iteration

To iterate the list simply use the following for loop

for (var node = fifo.node; node; node = fifo.next(node)) {
  console.log('value is', node.value)
}

Optionally you can call fifo.forEach(fn) which does the above internally.

License

MIT