github.com/jimmyx0x/go-ethereum@v1.10.28/rlp/iterator.go (about)

     1  // Copyright 2020 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  
    17  package rlp
    18  
    19  type listIterator struct {
    20  	data []byte
    21  	next []byte
    22  	err  error
    23  }
    24  
    25  // NewListIterator creates an iterator for the (list) represented by data
    26  // TODO: Consider removing this implementation, as it is no longer used.
    27  func NewListIterator(data RawValue) (*listIterator, error) {
    28  	k, t, c, err := readKind(data)
    29  	if err != nil {
    30  		return nil, err
    31  	}
    32  	if k != List {
    33  		return nil, ErrExpectedList
    34  	}
    35  	it := &listIterator{
    36  		data: data[t : t+c],
    37  	}
    38  	return it, nil
    39  }
    40  
    41  // Next forwards the iterator one step, returns true if it was not at end yet
    42  func (it *listIterator) Next() bool {
    43  	if len(it.data) == 0 {
    44  		return false
    45  	}
    46  	_, t, c, err := readKind(it.data)
    47  	it.next = it.data[:t+c]
    48  	it.data = it.data[t+c:]
    49  	it.err = err
    50  	return true
    51  }
    52  
    53  // Value returns the current value
    54  func (it *listIterator) Value() []byte {
    55  	return it.next
    56  }
    57  
    58  func (it *listIterator) Err() error {
    59  	return it.err
    60  }