70 lines
1.1 KiB
Go
70 lines
1.1 KiB
Go
|
package iter
|
||
|
|
|
||
|
|
import (
|
||
|
|
"sync"
|
||
|
|
|
||
|
|
"github.com/anacrolix/missinggo"
|
||
|
|
)
|
||
|
|
|
||
|
|
type Iterable interface {
|
||
|
|
Iter(Callback)
|
||
|
|
}
|
||
|
|
|
||
|
|
type iterator struct {
|
||
|
|
it Iterable
|
||
|
|
ch chan interface{}
|
||
|
|
value interface{}
|
||
|
|
ok bool
|
||
|
|
mu sync.Mutex
|
||
|
|
stopped missinggo.Event
|
||
|
|
}
|
||
|
|
|
||
|
|
func NewIterator(it Iterable) (ret *iterator) {
|
||
|
|
ret = &iterator{
|
||
|
|
it: it,
|
||
|
|
ch: make(chan interface{}),
|
||
|
|
}
|
||
|
|
go func() {
|
||
|
|
// Have to do this in a goroutine, because the interface is synchronous.
|
||
|
|
it.Iter(func(value interface{}) bool {
|
||
|
|
select {
|
||
|
|
case ret.ch <- value:
|
||
|
|
return true
|
||
|
|
case <-ret.stopped.LockedChan(&ret.mu):
|
||
|
|
return false
|
||
|
|
}
|
||
|
|
})
|
||
|
|
close(ret.ch)
|
||
|
|
ret.mu.Lock()
|
||
|
|
ret.stopped.Set()
|
||
|
|
ret.mu.Unlock()
|
||
|
|
}()
|
||
|
|
return
|
||
|
|
}
|
||
|
|
|
||
|
|
func (me *iterator) Value() interface{} {
|
||
|
|
if !me.ok {
|
||
|
|
panic("no value")
|
||
|
|
}
|
||
|
|
return me.value
|
||
|
|
}
|
||
|
|
|
||
|
|
func (me *iterator) Next() bool {
|
||
|
|
me.value, me.ok = <-me.ch
|
||
|
|
return me.ok
|
||
|
|
}
|
||
|
|
|
||
|
|
func (me *iterator) Stop() {
|
||
|
|
me.mu.Lock()
|
||
|
|
me.stopped.Set()
|
||
|
|
me.mu.Unlock()
|
||
|
|
}
|
||
|
|
|
||
|
|
func IterableAsSlice(it Iterable) (ret []interface{}) {
|
||
|
|
it.Iter(func(value interface{}) bool {
|
||
|
|
ret = append(ret, value)
|
||
|
|
return true
|
||
|
|
})
|
||
|
|
return
|
||
|
|
}
|