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package iter
import "github.com/anacrolix/missinggo/slices"
type Iterator interface {
// Advances to the next value. Returns false if there are no more values.
// Must be called before the first value.
Next() bool
// Returns the current value. Should panic when the iterator is in an
// invalid state.
Value() interface{}
// Ceases iteration prematurely. This should occur implicitly if Next
// returns false.
Stop()
}
func ToFunc(it Iterator) Func {
return func(cb Callback) {
defer it.Stop()
for it.Next() {
if !cb(it.Value()) {
break
}
}
}
}
type sliceIterator struct {
slice []interface{}
value interface{}
ok bool
}
func (me *sliceIterator) Next() bool {
if len(me.slice) == 0 {
return false
}
me.value = me.slice[0]
me.slice = me.slice[1:]
me.ok = true
return true
}
func (me *sliceIterator) Value() interface{} {
if !me.ok {
panic("no value; call Next")
}
return me.value
}
func (me *sliceIterator) Stop() {}
func Slice(a []interface{}) Iterator {
return &sliceIterator{
slice: a,
}
}
func StringIterator(a string) Iterator {
return Slice(slices.ToEmptyInterface(a))
}
func ToSlice(f Func) (ret []interface{}) {
f(func(v interface{}) bool {
ret = append(ret, v)
return true
})
return
}
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