forked from casdoor/casdoor
60 lines
1.6 KiB
Go
60 lines
1.6 KiB
Go
// Copyright 2023 The casbin Authors. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package util
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// Stack is a stack data structure implemented using a slice
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type Stack struct {
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items []interface{}
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}
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// Push adds an item to the stack
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func (s *Stack) Push(item interface{}) {
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s.items = append(s.items, item)
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}
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// Pop removes and returns the last item from the stack
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func (s *Stack) Pop() (interface{}, bool) {
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if len(s.items) == 0 {
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return nil, false // Return a sentinel value or you could handle this more gracefully
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}
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lastIndex := len(s.items) - 1
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item := s.items[lastIndex]
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s.items = s.items[:lastIndex]
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return item, true
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}
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// Peek returns the last item from the stack without removing it
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func (s *Stack) Peek() interface{} {
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if len(s.items) == 0 {
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return -1
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}
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return s.items[len(s.items)-1]
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}
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// IsEmpty checks if the stack is empty
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func (s *Stack) IsEmpty() bool {
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return len(s.items) == 0
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}
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// Size returns the number of items in the stack
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func (s *Stack) Size() int {
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return len(s.items)
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}
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// NewStack creates a new stack
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func NewStack() *Stack {
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return &Stack{}
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}
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