New updates and modules

node_modules/abstract-leveldown/abstract-iterator.js

@@ -0,0 +1,77 @@
+var nextTick = require('./next-tick')
+
+function AbstractIterator (db) {
+  if (typeof db !== 'object' || db === null) {
+    throw new TypeError('First argument must be an abstract-leveldown compliant store')
+  }
+
+  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) {
+    nextTick(callback, new Error('cannot call next() after end()'))
+    return self
+  }
+
+  if (self._nexting) {
+    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) {
+  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 nextTick(callback, new Error('end() already called on iterator'))
+  }
+
+  this._ended = true
+  this._end(callback)
+}
+
+AbstractIterator.prototype._end = function (callback) {
+  nextTick(callback)
+}
+
+// Expose browser-compatible nextTick for dependents
+AbstractIterator.prototype._nextTick = nextTick
+
+module.exports = AbstractIterator