iterator.go 1.7 KB

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  1. // Copyright 2019 The go-ethereum Authors
  2. // This file is part of the go-ethereum library.
  3. //
  4. // The go-ethereum library is free software: you can redistribute it and/or modify
  5. // it under the terms of the GNU Lesser General Public License as published by
  6. // the Free Software Foundation, either version 3 of the License, or
  7. // (at your option) any later version.
  8. //
  9. // The go-ethereum library is distributed in the hope that it will be useful,
  10. // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11. // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12. // GNU Lesser General Public License for more details.
  13. //
  14. // You should have received a copy of the GNU Lesser General Public License
  15. // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
  16. package rlp
  17. type listIterator struct {
  18. data []byte
  19. next []byte
  20. err error
  21. }
  22. // NewListIterator creates an iterator for the (list) represented by data
  23. // TODO: Consider removing this implementation, as it is no longer used.
  24. func NewListIterator(data RawValue) (*listIterator, error) {
  25. k, t, c, err := readKind(data)
  26. if err != nil {
  27. return nil, err
  28. }
  29. if k != List {
  30. return nil, ErrExpectedList
  31. }
  32. it := &listIterator{
  33. data: data[t : t+c],
  34. }
  35. return it, nil
  36. }
  37. // Next forwards the iterator one step, returns true if it was not at end yet
  38. func (it *listIterator) Next() bool {
  39. if len(it.data) == 0 {
  40. return false
  41. }
  42. _, t, c, err := readKind(it.data)
  43. it.next = it.data[:t+c]
  44. it.data = it.data[t+c:]
  45. it.err = err
  46. return true
  47. }
  48. // Value returns the current value
  49. func (it *listIterator) Value() []byte {
  50. return it.next
  51. }
  52. func (it *listIterator) Err() error {
  53. return it.err
  54. }