49 lines
1.3 KiB
Go
49 lines
1.3 KiB
Go
package iterator
|
|
|
|
import (
|
|
"github.com/nspcc-dev/neo-go/pkg/core/interop"
|
|
"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
|
|
)
|
|
|
|
type iterator interface {
|
|
Next() bool
|
|
Value() stackitem.Item
|
|
}
|
|
|
|
// Next advances the iterator, pushes true on success and false otherwise.
|
|
func Next(ic *interop.Context) error {
|
|
iop := ic.VM.Estack().Pop().Interop()
|
|
arr := iop.Value().(iterator)
|
|
ic.VM.Estack().PushItem(stackitem.Bool(arr.Next()))
|
|
|
|
return nil
|
|
}
|
|
|
|
// Value returns current iterator value and depends on iterator type:
|
|
// For slices the result is just value.
|
|
// For maps the result is key-value pair packed in a struct.
|
|
func Value(ic *interop.Context) error {
|
|
iop := ic.VM.Estack().Pop().Interop()
|
|
arr := iop.Value().(iterator)
|
|
ic.VM.Estack().PushItem(arr.Value())
|
|
|
|
return nil
|
|
}
|
|
|
|
// IsIterator returns whether stackitem implements iterator interface.
|
|
func IsIterator(item stackitem.Item) bool {
|
|
_, ok := item.Value().(iterator)
|
|
return ok
|
|
}
|
|
|
|
// Values returns an array of up to `max` iterator values. The second
|
|
// return parameter denotes whether iterator is truncated.
|
|
func Values(item stackitem.Item, max int) ([]stackitem.Item, bool) {
|
|
var result []stackitem.Item
|
|
arr := item.Value().(iterator)
|
|
for arr.Next() && max > 0 {
|
|
result = append(result, arr.Value())
|
|
max--
|
|
}
|
|
return result, arr.Next()
|
|
}
|