IteratorInstance.cs 6.8 KB

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  1. using System.Globalization;
  2. using Jint.Native.Generator;
  3. using Jint.Native.Object;
  4. using Jint.Native.RegExp;
  5. using Jint.Runtime;
  6. namespace Jint.Native.Iterator;
  7. internal abstract class IteratorInstance : ObjectInstance
  8. {
  9. protected IteratorInstance(Engine engine) : base(engine)
  10. {
  11. _prototype = engine.Realm.Intrinsics.ArrayIteratorPrototype;
  12. }
  13. public override object ToObject()
  14. {
  15. ExceptionHelper.ThrowNotImplementedException();
  16. return null;
  17. }
  18. public abstract bool TryIteratorStep(out ObjectInstance nextItem);
  19. public virtual void Close(CompletionType completion)
  20. {
  21. }
  22. /// <summary>
  23. /// https://tc39.es/ecma262/#sec-createiterresultobject
  24. /// </summary>
  25. private IteratorResult CreateIterResultObject(JsValue value, bool done)
  26. {
  27. return new IteratorResult(_engine, value, JsBoolean.Create(done));
  28. }
  29. internal sealed class ObjectIterator : IteratorInstance
  30. {
  31. private readonly ObjectInstance _target;
  32. private readonly ICallable _nextMethod;
  33. public ObjectIterator(ObjectInstance target) : base(target.Engine)
  34. {
  35. _target = target;
  36. if (target.Get(CommonProperties.Next) is not ICallable callable)
  37. {
  38. ExceptionHelper.ThrowTypeError(target.Engine.Realm);
  39. return;
  40. }
  41. _nextMethod = callable;
  42. }
  43. public override bool TryIteratorStep(out ObjectInstance result)
  44. {
  45. result = IteratorNext();
  46. var done = result.Get(CommonProperties.Done);
  47. if (!done.IsUndefined() && TypeConverter.ToBoolean(done))
  48. {
  49. return false;
  50. }
  51. return true;
  52. }
  53. private ObjectInstance IteratorNext()
  54. {
  55. var jsValue = _nextMethod.Call(_target, Arguments.Empty);
  56. var instance = jsValue as ObjectInstance;
  57. if (instance is null)
  58. {
  59. ExceptionHelper.ThrowTypeError(_target.Engine.Realm, $"Iterator result {jsValue} is not an object");
  60. }
  61. return instance;
  62. }
  63. public override void Close(CompletionType completion)
  64. {
  65. if (!_target.TryGetValue(CommonProperties.Return, out var func)
  66. || func.IsNullOrUndefined())
  67. {
  68. return;
  69. }
  70. var callable = func as ICallable;
  71. if (callable is null)
  72. {
  73. ExceptionHelper.ThrowTypeError(_target.Engine.Realm, func + " is not a function");
  74. }
  75. var innerResult = Undefined;
  76. try
  77. {
  78. innerResult = callable.Call(_target, Arguments.Empty);
  79. }
  80. catch
  81. {
  82. if (completion != CompletionType.Throw)
  83. {
  84. throw;
  85. }
  86. }
  87. if (completion != CompletionType.Throw && !innerResult.IsObject())
  88. {
  89. ExceptionHelper.ThrowTypeError(_target.Engine.Realm, "Iterator returned non-object");
  90. }
  91. }
  92. }
  93. internal sealed class StringIterator : IteratorInstance
  94. {
  95. private readonly TextElementEnumerator _iterator;
  96. public StringIterator(Engine engine, string str) : base(engine)
  97. {
  98. _iterator = StringInfo.GetTextElementEnumerator(str);
  99. }
  100. public override bool TryIteratorStep(out ObjectInstance nextItem)
  101. {
  102. if (_iterator.MoveNext())
  103. {
  104. nextItem = IteratorResult.CreateValueIteratorPosition(_engine, (string) _iterator.Current);
  105. return true;
  106. }
  107. nextItem = IteratorResult.CreateKeyValueIteratorPosition(_engine);
  108. return false;
  109. }
  110. }
  111. internal sealed class RegExpStringIterator : IteratorInstance
  112. {
  113. private readonly JsRegExp _iteratingRegExp;
  114. private readonly string _s;
  115. private readonly bool _global;
  116. private readonly bool _unicode;
  117. private bool _done;
  118. public RegExpStringIterator(Engine engine, ObjectInstance iteratingRegExp, string iteratedString, bool global, bool unicode) : base(engine)
  119. {
  120. var r = iteratingRegExp as JsRegExp;
  121. if (r is null)
  122. {
  123. ExceptionHelper.ThrowTypeError(engine.Realm);
  124. }
  125. _iteratingRegExp = r;
  126. _s = iteratedString;
  127. _global = global;
  128. _unicode = unicode;
  129. }
  130. public override bool TryIteratorStep(out ObjectInstance nextItem)
  131. {
  132. if (_done)
  133. {
  134. nextItem = CreateIterResultObject(Undefined, true);
  135. return false;
  136. }
  137. var match = RegExpPrototype.RegExpExec(_iteratingRegExp, _s);
  138. if (match.IsNull())
  139. {
  140. _done = true;
  141. nextItem = CreateIterResultObject(Undefined, true);
  142. return false;
  143. }
  144. if (_global)
  145. {
  146. var macthStr = TypeConverter.ToString(match.Get(JsString.NumberZeroString));
  147. if (macthStr == "")
  148. {
  149. var thisIndex = TypeConverter.ToLength(_iteratingRegExp.Get(JsRegExp.PropertyLastIndex));
  150. var nextIndex = thisIndex + 1;
  151. _iteratingRegExp.Set(JsRegExp.PropertyLastIndex, nextIndex, true);
  152. }
  153. }
  154. else
  155. {
  156. _done = true;
  157. }
  158. nextItem = CreateIterResultObject(match, false);
  159. return true;
  160. }
  161. }
  162. internal sealed class EnumerableIterator : IteratorInstance
  163. {
  164. private readonly IEnumerator<JsValue> _enumerable;
  165. public EnumerableIterator(Engine engine, IEnumerable<JsValue> obj) : base(engine)
  166. {
  167. _enumerable = obj.GetEnumerator();
  168. }
  169. public override bool TryIteratorStep(out ObjectInstance nextItem)
  170. {
  171. if (_enumerable.MoveNext())
  172. {
  173. nextItem = IteratorResult.CreateValueIteratorPosition(_engine, _enumerable.Current);
  174. return true;
  175. }
  176. nextItem = IteratorResult.CreateValueIteratorPosition(_engine, done: JsBoolean.True);
  177. return false;
  178. }
  179. }
  180. internal sealed class GeneratorIterator : IteratorInstance
  181. {
  182. private readonly GeneratorInstance _generator;
  183. public GeneratorIterator(Engine engine, GeneratorInstance generator) : base(engine)
  184. {
  185. _generator = generator;
  186. }
  187. public override bool TryIteratorStep(out ObjectInstance nextItem)
  188. {
  189. nextItem = IteratorResult.CreateValueIteratorPosition(_engine, done: JsBoolean.True);
  190. return false;
  191. }
  192. }
  193. }