Golang Iterator for ordered map

1. The order of the elements in the map.

2. Transparent use *interface{} as value.

Installation

$ go get github.com/mantyr/iterator

Examples

package main
import (
"github.com/mantyr/iterator""fmt""strconv"
)
typeObjstruct {
param1intparam2string
}
funcmain() {
items:=iterator.New()
items.Add("test1", "value1")
items.Add("test2", "value2")
items.Add("test2", "value2")
items.Add("test3", "value3")
items.Add("test4", "value4")
fmt.Println("Ordered map:")
foritem:=rangeitems.Iter() {
fmt.Printf("Position %q, key %q, value %q \r\n", strconv.Itoa(item.Index), item.Key, item.Value)
}
fmt.Println("Default map:")
forkey, value:=rangeitems.Items {
fmt.Printf("Key %q, value %q \r\n", key, value)
}
// for *objobj:=new(Obj)
obj.param1=10obj.param2="test1"items=iterator.New()
items.Add("test5", obj)
fmt.Println("Ordered map *:")
foritem:=rangeitems.Iter() {
fmt.Printf("Position %q, key %q, value param2 %q \r\n", strconv.Itoa(item.Index), item.Key, item.Value.(*Obj).param2)
}
fmt.Println("Default map *:")
forkey, value:=rangeitems.Items {
fmt.Printf("Key %q, value param2 %q \r\n", key, value.(*Obj).param2)
}
}
/* outOrdered map:Position "0", key "test1", value "value1" Position "1", key "test2", value "value2" Position "2", key "test3", value "value3" Position "3", key "test4", value "value4" Default map:Key "test2", value "value2" Key "test3", value "value3" Key "test4", value "value4" Key "test1", value "value1" Ordered map *:Position "0", key "test5", value param2 "test1" Default map *:Key "test5", value param2 "test1"*/

Notice

Not use channel if you use "back" in loop. See also #1

package main
import (
"github.com/mantyr/iterator"
)
funcmain() {
items:=iterator.New()
fori:=0; i<100; i++ {
items.Add(i, i)
}
i:=0for_, key:=rangeitems.Keys {
item, ok:=items.Get(key)
if!ok {
continue
}
ifitem==10 {
break
}
i++
}
}

Example for html/template and helper function for objects

package main
import (
"log""net/http""github.com/gorilla/context""github.com/mantyr/iterator""html/template"
)
funcmain() {
http.HandleFunc("/test", handler_iterator)
iferr:=http.ListenAndServe(":8080", context.ClearHandler(http.DefaultServeMux)); err!=nil {
log.Fatal("ListenAndServe:", err)
}
}
typeObjstruct {
IdintSearchstring
}
typeObjMapstruct {
Valuesmap[string]string
}
func (o*ObjMap) Get(keystring) string {
val, ok:=o.Values[key]
ifok {
returnval
}
return""
}
funchandler_iterator(w http.ResponseWriter, r*http.Request) {
vartmpl=template.Must(template.ParseFiles("tmpl/index.html"))
items_st:=iterator.New()
items_st.Add("test1", "value1")
items_st.Add("test2", "value2")
items_st.Add("test2", "value2")
items_st.Add("test3", "value3")
items_st.Add("test4", "value4")
items:=iterator.New()
obj1:=Obj{1, "test1"}
obj2:=Obj{2, "test2"}
obj3:=Obj{3, "test3"}
items.Add("test1", obj1)
items.Add("test2", obj2)
items.Add("test3", obj3)
items_ob:=iterator.New()
obj_m1:=new(ObjMap)
obj_m2:=new(ObjMap)
obj_m3:=new(ObjMap)
obj_m1.Values=make(map[string]string)
obj_m1.Values["id"] ="1"obj_m1.Values["value"] ="test1"obj_m2.Values=make(map[string]string)
obj_m2.Values["id"] ="2"obj_m2.Values["value"] ="test2"obj_m3.Values=make(map[string]string)
obj_m3.Values["id"] ="3"obj_m3.Values["value"] ="test3"items_ob.Add("test1", obj_m1)
items_ob.Add("test2", obj_m2)
items_ob.Add("test3", obj_m3)
data:=struct {
ItemsString<-chan iterator.ItemItems<-chan iterator.ItemItemsObj<-chan iterator.Item
}{items_st.Iter(), items.Iter(), items_ob.Iter()}
tmpl.Execute(w, data)
}

$ cat tmpl/index.html

<divclass="content">
{{range $item := .ItemsString}}
<divclass="item finish" data-id="{{$item.Key}}">{{$item.Value}}</div>
{{end}}
</div><divclass="content">
{{range $item := .Items}}
<divclass="item finish" data-id="{{$item.Value.Id}}">{{$item.Value.Search}}</div>
{{end}}
</div><divclass="content">
{{range $item := .ItemsObj}}
<divclass="item finish" data-id="{{$item.Value.Get "id"}}">{{$item.Value.Get "value"}}</div>
{{end}}
</div>

http://localhost:8080/test

<divclass="content"><divclass="item finish" data-id="test1">value1</div><divclass="item finish" data-id="test2">value2</div><divclass="item finish" data-id="test3">value3</div><divclass="item finish" data-id="test4">value4</div></div><divclass="content"><divclass="item finish" data-id="1">test1</div><divclass="item finish" data-id="2">test2</div><divclass="item finish" data-id="3">test3</div></div><divclass="content"><divclass="item finish" data-id="1">test1</div><divclass="item finish" data-id="2">test2</div><divclass="item finish" data-id="3">test3</div></div>

More Examples

$ cat iterator_test.go

Author

Oleg Shevelev