Cacher is the code snippet organizer for pro developers

package main

import (
	"fmt"
	"sync"
)

type Node struct {
	value int
	next  *Node
}

type StackOfInts struct {
	head   *Node
	length int
	sync.Mutex
}

func (s *StackOfInts) Push(n int) {
	s.Lock()
	defer s.Unlock()
	this := s.head
	s.head = &Node{
		value: n,
		next:  this,
	}
	s.length++
}

func (s *StackOfInts) Pop() int {
	s.Lock()
	defer s.Unlock()
	popped := s.head
	s.head = s.head.next
	s.length--
	return popped.value
}

func (s *StackOfInts) Len() int {
	s.Lock()
	defer s.Unlock()
	return s.length
}

func (s *StackOfInts) IsEmpty() bool {
	s.Lock()
	defer s.Unlock()
	return s.head == nil
}

func NewStack() *StackOfInts {
	return &StackOfInts{
		head: nil,
	}
}

func main() {
	s := NewStack()
	s.Push(10)
	s.Push(20)
	s.Push(30)
	s.Push(40)
	for s.Len() > 0 {
		fmt.Println(s.Pop())
	}
	fmt.Println(s.IsEmpty())

}