README.md

laney

Fork of https://github.com/oleiade/lane to make it generic and update to latest Go

Laney package provides queue, priority queue, stack and deque data structures implementations. Its was designed with simplicity, performance, and concurrent usage in mind.

Priority Queue

Pqueue is a heap priority queue data structure implementation. It can be whether max or min ordered, is synchronized and is safe for concurrent operations. It performs insertion and max/min removal in O(log N) time.

Priority Queue Example

 // Let's create a new max ordered priority queue
 var priorityQueue = NewPQueue[string](MINPQ)

 // And push some prioritized content into it
 priorityQueue.Push("easy as", 3)
 priorityQueue.Push("123", 2)
 priorityQueue.Push("do re mi", 4)
 priorityQueue.Push("abc", 1)

 // Now let's take a look at the min element in
 // the priority queue
 headValue, headPriority := priorityQueue.Head()
 fmt.Println(headValue)    // "abc"
 fmt.Println(headPriority) // 1

 // Okay the song order seems to be preserved, let's
 // roll
 var jacksonFive = make([]string, priorityQueue.Size())

 for i := 0; i < len(jacksonFive); i++ {
  value, _ := priorityQueue.Pop()

  jacksonFive[i] = value
 }

 fmt.Println(strings.Join(jacksonFive, " "))

Deque

Deque is a head-tail linked list data structure implementation. It is based on a doubly-linked list container, so that every operations time complexity is O(1). All operations over an instiated Deque are synchronized and safe for concurrent usage.

Deques can optionally be created with a limited capacity, whereby the return value of the Append and Prepend return false if the Deque was full and the item was not added.

Deque Example

 // Let's create a new deque data structure
 deque := NewDeque[string]()

 // And push some content into it using the Append
 // and Prepend methods
 deque.Append("easy as")
 deque.Prepend("123")
 deque.Append("do re mi")
 deque.Prepend("abc")

 // Now let's take a look at what are the first and
 // last element stored in the Deque
 firstValue := deque.First()
 lastValue := deque.Last()
 fmt.Println(firstValue) // "abc"
 fmt.Println(lastValue)  // 1

 // Okay now let's play with the Pop and Shift
 // methods to bring the song words together
 jacksonFive := make([]string, deque.Size())

 for i := 0; i < len(jacksonFive); i++ {
  value := deque.Shift()
  jacksonFive[i] = value
 }

 // abc 123 easy as do re mi
 fmt.Println(strings.Join(jacksonFive, " "))

 // Let's create a new musical quartet
 quartet := NewCappedDeque[string](4)

 // List of young hopeful musicians
 musicians := []string{"John", "Paul", "George", "Ringo", "Stuart"}

 // Add as many of them to the band as we can.
 for _, name := range musicians {
  if quartet.Append(name) {
   fmt.Printf("%s is in the band!\n", name)
  } else {
   fmt.Printf("Sorry - %s is not in the band.\n", name)
  }
 }

 // Assemble our new rock sensation
 beatles := make([]string, quartet.Size())

 for i := 0; i < len(beatles); i++ {
  beatles[i] = quartet.Shift()
 }

 fmt.Println("The Beatles are:", strings.Join(beatles, ", "))

Queue

Queue is a FIFO ( First in first out ) data structure implementation. It is based on a deque container and focuses its API on core functionalities: Enqueue, Dequeue, Head, Size, Empty. Every operations time complexity is O(1). As it is implemented using a Deque container, every operations over an instiated Queue are synchronized and safe for concurrent usage.

Queue Example

    import (
        "fmt"
        "github.com/oleiade/laney"
        "sync"
    )

    func worker(item string, wg *sync.WaitGroup) {
        fmt.Println(item)
        wg.Done()
    }


    func main() {

        queue := laney.NewQueue[string]()
        queue.Enqueue("grumpyClient")
        queue.Enqueue("happyClient")
        queue.Enqueue("ecstaticClient")

        var wg sync.WaitGroup

        // Let's handle the clients asynchronously
        for queue.Head() != nil {
            item := queue.Dequeue()

            wg.Add(1)
            go worker(item, &wg)
        }

        // Wait until everything is printed
        wg.Wait()
    }

Stack

Stack is a LIFO ( Last in first out ) data structure implementation. It is based on a deque container and focuses its API on core functionalities: Push, Pop, Head, Size, Empty. Every operations time complexity is O(1). As it is implemented using a Deque container, every operations over an instiated Stack are synchronized and safe for concurrent usage.

Stack Example

 // Create a new stack and put some plates over it
 stack := NewStack[string]()

 // Let's put some plates on the stack
 stack.Push("redPlate")
 stack.Push("bluePlate")
 stack.Push("greenPlate")

 fmt.Println(stack.Head) // greenPlate

 // What's on top of the stack?
 value := stack.Pop()
 fmt.Println(value) // greenPlate

 stack.Push("yellowPlate")
 value = stack.Pop()
 fmt.Println(value) // yellowPlate

 // What's on top of the stack?
 value = stack.Pop()
 fmt.Println(value) // bluePlate

 // What's on top of the stack?
 value = stack.Pop()
 fmt.Println(value) // redPlate

Documentation

For a more detailled overview of laney, please refer to Documentation