List created by miry - https://repl.it/@miry/List

List.go

package main

import "fmt"
import "errors"

type Node struct {
  next *Node
  value string
}

func (n *Node) Append(next *Node) {
  last := n
  for node := n; node != nil; node = node.next {
    last = node
  }
  last.next = next
}

func (n *Node) Delete(pos int) (*Node, error) {
  if pos == 0 {
    result := n.next
    n.next = nil
    return result, nil
  }
  
  node, err := n.Get(pos-1)  
  
  if err != nil {
    return n, err
  }

  subject := node.next
  next := subject.next
  node.next = next
  subject.next = nil

  return n, err
}

func (n *Node) Get(pos int) (*Node, error) {
  if pos < 0 {
    return nil, errors.New("Out of index")
  }
  
  node := n
  for i := 0; i < pos; i++ {
    if node.next == nil {
      return nil, errors.New("Out of index")
    }
    node = node.next
  }
  return node, nil
}

func (n *Node) Insert(pos int, next *Node) (*Node, error) {
  if pos == 0 {
    next.next = n
    return next, nil
  }
  
  node, err := n.Get(pos-1)  
  
  if err != nil {
    return n, err
  }

  old := node.next
  next.next = old
  node.next = next

  return n, err
}


func (n *Node) Print() {
  for node := n; node != nil; node = node.next {
    fmt.Println(node.value)
  }
}

func main() {
  fmt.Println("## Example of the List implementation")
  first := &Node{value: "First node"}
  first.Print()
  
  fmt.Println()
  fmt.Println("### Append element")
  second := &Node{value: "Second node"}
  third  := &Node{value: "Third node"}
  first.next = second
  first.Append(third)
  first.Print()
  
  fmt.Println()
  fmt.Println("### Get element")
  second, _ = first.Get(1)
  fmt.Println("Get second node:", second.value)
  third, _ = first.Get(2)
  fmt.Println("Get third node: ", third.value)
  _, err := first.Get(3)
  if err != nil {
    fmt.Println("ERROR: ", err)
  } else {
    panic("Should not come here")
  }
  
  fmt.Println()
  fmt.Println("### Insert element")
  newSecond := &Node{value: "New Second"}
  first.Insert(1, newSecond)
  oops := &Node{value: "Should not be in the list"}
  first, err = first.Insert(6, oops)
  if err != nil {
    fmt.Println("ERROR: ", err)
  } else {
    panic("Should not come here")
  }
  newFirst := &Node{value: "New First"}
  first, _ = first.Insert(0, newFirst)
  first.Print()
  
  fmt.Println()
  fmt.Println("### Delete element")
  first, _ = first.Delete(0)
  first, _ = first.Delete(3)
  first.Print()
}