goext/dataext/stack.go

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package dataext
import (
"errors"
"gogs.mikescher.com/BlackForestBytes/goext/langext"
"sync"
)
var ErrEmptyStack = errors.New("stack is empty")
type Stack[T any] struct {
lock *sync.Mutex
data []T
}
func NewStack[T any](threadsafe bool, initialCapacity int) *Stack[T] {
var lck *sync.Mutex = nil
if threadsafe {
lck = &sync.Mutex{}
}
return &Stack[T]{
lock: lck,
data: make([]T, 0, initialCapacity),
}
}
func (s *Stack[T]) Push(v T) {
if s.lock != nil {
s.lock.Lock()
defer s.lock.Unlock()
}
s.data = append(s.data, v)
}
func (s *Stack[T]) Pop() (T, error) {
if s.lock != nil {
s.lock.Lock()
defer s.lock.Unlock()
}
l := len(s.data)
if l == 0 {
return *new(T), ErrEmptyStack
}
result := s.data[l-1]
s.data = s.data[:l-1]
return result, nil
}
func (s *Stack[T]) OptPop() *T {
if s.lock != nil {
s.lock.Lock()
defer s.lock.Unlock()
}
l := len(s.data)
if l == 0 {
return nil
}
result := s.data[l-1]
s.data = s.data[:l-1]
return langext.Ptr(result)
}
func (s *Stack[T]) Peek() (T, error) {
if s.lock != nil {
s.lock.Lock()
defer s.lock.Unlock()
}
l := len(s.data)
if l == 0 {
return *new(T), ErrEmptyStack
}
return s.data[l-1], nil
}
func (s *Stack[T]) OptPeek() *T {
if s.lock != nil {
s.lock.Lock()
defer s.lock.Unlock()
}
l := len(s.data)
if l == 0 {
return nil
}
return langext.Ptr(s.data[l-1])
}
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func (s *Stack[T]) Length() int {
if s.lock != nil {
s.lock.Lock()
defer s.lock.Unlock()
}
return len(s.data)
}
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func (s *Stack[T]) Empty() bool {
if s.lock != nil {
s.lock.Lock()
defer s.lock.Unlock()
}
return len(s.data) == 0
}