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stack.go
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stack.go
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/*
* MIT License
*
* Copyright (c) 2022-2024 Tochemey
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
package stack
import "sync"
// Stack is a last-in-first-out data structure
type Stack[T any] struct {
mutex sync.Mutex
items []T
}
// New creates a new stack
func New[T any]() *Stack[T] {
return &Stack[T]{
mutex: sync.Mutex{},
items: make([]T, 0),
}
}
// Peek helps view the top item on the stack
func (s *Stack[T]) Peek() (item T, ok bool) {
// acquire the lock
s.mutex.Lock()
// release the lock
defer s.mutex.Unlock()
if length := len(s.items); length > 0 {
ok = true
item = s.items[length-1]
}
return
}
// Pop removes and return top element of stack. Return false if stack is empty.
func (s *Stack[T]) Pop() (item T, ok bool) {
// acquire the lock
s.mutex.Lock()
// release the lock
defer s.mutex.Unlock()
if length := len(s.items); length > 0 {
// get the index of the top most element.
length--
ok = true
// index into the slice and obtain the element.
item = s.items[length]
// remove it from the stack by slicing it off.
s.items = s.items[:length]
}
return
}
// Push a new value onto the stack
func (s *Stack[T]) Push(item T) {
// acquire the lock
s.mutex.Lock()
// release the lock
defer s.mutex.Unlock()
s.items = append(s.items, item)
}
// Len returns the length of the stack.
func (s *Stack[T]) Len() int {
// acquire the lock
s.mutex.Lock()
// release the lock
defer s.mutex.Unlock()
return len(s.items)
}
// IsEmpty checks if stack is empty
func (s *Stack[T]) IsEmpty() bool {
return s.Len() == 0
}
// Clear empty the stack
func (s *Stack[T]) Clear() {
// acquire the lock
s.mutex.Lock()
// release the lock
defer s.mutex.Unlock()
if len(s.items) == 0 {
return
}
s.items = []T{}
}