phodal/coca

package container

import (
    l "container/list"
    "sync"
)

type Stack struct {
    list *l.List
    mu sync.Mutex
}

func NewStack() *Stack {
    list := l.New()
    return &Stack{list: list,}
}

func (s *Stack) Push(t interface{}){
    s.mu.Lock()
    defer s.mu.Unlock()
    s.list.PushFront(t)
}

func  (s *Stack) Pop() interface{} {
    s.mu.Lock()
    defer s.mu.Unlock()
    ele := s.list.Front()
    if nil != ele {
        s.list.Remove(ele)
        return ele.Value
    }

    return nil
}

func (s *Stack) Peak() interface{} {
    s.mu.Lock()
    defer s.mu.Unlock()
    ele := s.list.Front()
    return ele.Value
}

func (s *Stack) Len() int {
    return s.list.Len()
}

func (s *Stack) IsEmpty() bool {
    return s.list.Len() == 0
}