"Cold snow" Go implementation iterator mode

Iterator Pattern

The iterator pattern allows the object to be accessed in a way that can be encapsulated, only to implement its own iterator to a data structure, and the user can easily manipulate the data structure without needing to care about the underlying implementation simply by getting an iterator. Implement

Encapsulating a container

Package iterator

Import "container/list"

type container interface{
    iterator () iterator
}

type List struct{List List
    . List
}

func (this *list) Iterator () iterator{
    return &listiterator{this.list.front (), This.list.Back ()}
}

func (this *list) Add (value interface{}) {
    this.list.PushBack (value)
}

Implementing iterators for containers

Package iterator

Import (
    "Container/list"
)

type iterator interface{
    hasnext () bool
    Value ( ) interface{}
    Next ()
}

type listiterator struct {
    cur *list. Element
    End *list. Element
}

func (this *listiterator) hasnext () bool{
    return this.cur! = This.end
}

func (this * Listiterator) Next () {
    this.cur=this.cur.next ()
}

func (this *listiterator) Value () interface{}{
    return This.cur.Value
}

Main.go

Package main

Import (
    "Projects/designpatternsbygo/behavioralpatterns/iterator"
    "FMT"
)

Func Main () {
    L: = iterator. list{}
    L.add (1)
    L.add (2)
    L.add (3)
    L.add (4)
    I: = L.iterator () for
    I.hasnext () {
        x: = I.value (). (int)
        Fmt. PRINTLN (x)
        i.next ()
    }
}

Money to hold a court, no money in the holding of personal field. It's not easy to come out.