如何用Golang实现迭代器遍历集合_Golang 迭代器模式集合遍历实践

type Iterator interface {
    Next() bool
    Value() interface{}
}

type SliceIterator struct {
    slice []string
    index int
}

func (it *SliceIterator) Next() bool {
    if it.index < len(it.slice) {
        it.index++
        return true
    }
    return false
}

func (it *SliceIterator) Value() interface{} {
    return it.slice[it.index-1]
}

data := []string{"apple", "banana", "cherry"}
iter := &SliceIterator{slice: data}

for iter.Next() {
    fmt.Println(iter.Value())
}

type SliceIterator[T any] struct {
    slice []T
    index int
}

func NewSliceIterator[T any](s []T) *SliceIterator[T] {
    return &SliceIterator[T]{slice: s}
}

func (it *SliceIterator[T]) Next() bool {
    if it.index < len(it.slice) {
        it.index++
        return true
    }
    return false
}

func (it *SliceIterator[T]) Value() T {
    return it.slice[it.index-1]
}

nums := []int{1, 2, 3}
iter := NewSliceIterator(nums)
for iter.Next() {
    fmt.Println(iter.Value()) // 输出 1, 2, 3
}

func NewCounterIterator(max int) func() (int, bool) {
    count := 0
    return func() (int, bool) {
        count++
        if count <= max {
            return count, true
        }
        return 0, false
    }
}

next := NewCounterIterator(3)
for {
    val, ok := next()
    if !ok {
        break
    }
    fmt.Println(val)
}