Simple Stack

simple_stack.go

package utils

import "sync"

type Stack struct {
	mutex sync.RWMutex
	data  []interface{}
}

func NewStack() Stack {
	return Stack{}
}

func NewStackWithValue(data interface{}) Stack {
	return Stack{
		data: []interface{}{data},
	}
}

func (s *Stack) Size() int {
	s.mutex.RLock()
	defer s.mutex.RUnlock()
	return len(s.data)
}

func (s *Stack) Empty() bool {
	s.mutex.RLock()
	defer s.mutex.RUnlock()
	return len(s.data) == 0
}

func (s *Stack) Push(value interface{}) {
	s.mutex.Lock()
	defer s.mutex.Unlock()
	s.data = append(s.data, value)
}

func (s *Stack) Pop() interface{} {
	s.mutex.Lock()
	defer s.mutex.Unlock()

	var ret interface{}
	if len(s.data) > 0 {
		n := len(s.data) - 1
		ret = s.data[n]
		s.data = s.data[:n]
	}
	return ret
}

func (s *Stack) Shift() interface{} {
	s.mutex.Lock()
	defer s.mutex.Unlock()

	var ret interface{}
	if len(s.data) > 0 {
		n := 0
		ret = s.data[n]
		s.data[n] = nil
		s.data = s.data[:n]
	}
	return ret
}