<commit_before>function AbstractIterator (db) {
  this.db = db
  this._ended = false
  this._nexting = false
}

AbstractIterator.prototype.next = function (callback) {
  var self = this

  if (typeof callback !== 'function') {
    throw new Error('next() requires a callback argument')
  }

  if (self._ended) {
    process.nextTick(callback, new Error('cannot call next() after end()'))
    return self
  }

  if (self._nexting) {
    process.nextTick(callback, new Error('cannot call next() before previous next() has completed'))
    return self
  }

  self._nexting = true
  self._next(function () {
    self._nexting = false
    callback.apply(null, arguments)
  })

  return self
}

AbstractIterator.prototype._next = function (callback) {
  process.nextTick(callback)
}

AbstractIterator.prototype.seek = function (target) {
  if (this._ended) {
    throw new Error('cannot call seek() after end()')
  }
  if (this._nexting) {
    throw new Error('cannot call seek() before next() has completed')
  }

  target = this.db._serializeKey(target)
  this._seek(target)
}

AbstractIterator.prototype._seek = function (callback) {
  process.nextTick(callback)
}

AbstractIterator.prototype.end = function (callback) {
  if (typeof callback !== 'function') {
    throw new Error('end() requires a callback argument')
  }

  if (this._ended) {
    return process.nextTick(callback, new Error('end() already called on iterator'))
  }<commit_msg>Fix bug in AbstractIterator#_seek (#302)<commit_after>function AbstractIterator (db) {
  this.db = db
  this._ended = false
  this._nexting = false
}

AbstractIterator.prototype.next = function (callback) {
  var self = this

  if (typeof callback !== 'function') {
    throw new Error('next() requires a callback argument')
  }

  if (self._ended) {
    process.nextTick(callback, new Error('cannot call next() after end()'))
    return self
  }

  if (self._nexting) {
    process.nextTick(callback, new Error('cannot call next() before previous next() has completed'))
    return self
  }

  self._nexting = true
  self._next(function () {
    self._nexting = false
    callback.apply(null, arguments)
  })

  return self
}

AbstractIterator.prototype._next = function (callback) {
  process.nextTick(callback)
}

AbstractIterator.prototype.seek = function (target) {
  if (this._ended) {
    throw new Error('cannot call seek() after end()')
  }
  if (this._nexting) {
    throw new Error('cannot call seek() before next() has completed')
  }

  target = this.db._serializeKey(target)
  this._seek(target)
}

AbstractIterator.prototype._seek = function (target) {}

AbstractIterator.prototype.end = function (callback) {
  if (typeof callback !== 'function') {
    throw new Error('end() requires a callback argument')
  }

  if (this._ended) {
    return process.nextTick(callback, new Error('end() already called on iterator'))
  }
{'fraction_non_alphanumeric': 0.1267801319902744, 'fraction_numerical': 0.0010420284821118443, 'mean_word_length': 3.8484848484848486, 'pattern_counts': {'":': 0, '<': 3, '<?xml version=': 0, '>': 3, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
{'dir': 'git-commits-cleaned', 'id': '2443692', 'n_tokens_mistral': 867, 'n_tokens_neox': 839, 'n_words': 239}