github.com/zuoyebang/bitalosdb@v1.1.1-0.20240516111551-79a8c4d8ce20/internal/list2/stack.go (about)

     1  // Copyright 2021 The Bitalosdb author(hustxrb@163.com) and other contributors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package list2
    16  
    17  import "container/list"
    18  
    19  type Stack struct {
    20  	list *list.List
    21  }
    22  
    23  func NewStack() *Stack {
    24  	l := list.New()
    25  	return &Stack{l}
    26  }
    27  
    28  func (stack *Stack) Push(value interface{}) {
    29  	stack.list.PushBack(value)
    30  }
    31  
    32  func (stack *Stack) Pop() interface{} {
    33  	e := stack.list.Back()
    34  	if e != nil {
    35  		stack.list.Remove(e)
    36  		return e.Value
    37  	}
    38  	return nil
    39  }
    40  
    41  func (stack *Stack) Peak() interface{} {
    42  	e := stack.list.Back()
    43  	if e != nil {
    44  		return e.Value
    45  	}
    46  
    47  	return nil
    48  }
    49  
    50  func (stack *Stack) Len() int {
    51  	return stack.list.Len()
    52  }
    53  
    54  func (stack *Stack) Empty() bool {
    55  	return stack.list.Len() == 0
    56  }