runtime/lib/errors_patch.dart - sdk.git - Git at Google

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.

 @patch
 class Error {
   @patch
   static String _objectToString(Object object) {
     return Object._toString(object);
   }

   @patch
   static String _stringToSafeString(String string) {
     return JSON.encode(string);
   }

   @patch
   StackTrace get stackTrace => _stackTrace;

   StackTrace _stackTrace;
 }

 class _AssertionError extends Error implements AssertionError {
   _AssertionError._create(
       this._failedAssertion, this._url, this._line, this._column, this.message);

   // AssertionError_throwNew in errors.cc fishes the assertion source code
   // out of the script. It expects a Dart stack frame from class
   // _AssertionError. Thus we need a Dart stub that calls the native code.
   static _throwNew(int assertionStart, int assertionEnd, Object message) {
     _doThrowNew(assertionStart, assertionEnd, message);
   }

   static _doThrowNew(int assertionStart, int assertionEnd, Object message)
       native "AssertionError_throwNew";

   static _evaluateAssertion(condition) {
     if (identical(condition, true) || identical(condition, false)) {
       return condition;
     }
     if (condition is _Closure) {
       return condition();
     }
     if (condition is Function) {
       condition = condition();
     }
     return condition;
   }

   String get _messageString {
     if (message == null) return "is not true.";
     if (message is String) return message;
     return Error.safeToString(message);
   }

   String toString() {
     if (_url == null) {
       if (message == null) return _failedAssertion;
       return "'$_failedAssertion': $_messageString";
     }
     var columnInfo = "";
     if (_column > 0) {
       // Only add column information if it is valid.
       columnInfo = " pos $_column";
     }
     return "'$_url': Failed assertion: line $_line$columnInfo: "
         "'$_failedAssertion': $_messageString";
   }

   final String _failedAssertion;
   final String _url;
   final int _line;
   final int _column;
   final Object message;
 }

 class _TypeError extends _AssertionError implements TypeError {
   _TypeError._create(String url, int line, int column, String errorMsg)
       : super._create("is assignable", url, line, column, errorMsg);

   static _throwNew(int location, Object src_value, _Type dst_type,
       String dst_name, String bound_error_msg) native "TypeError_throwNew";

   static _throwNewIfNotLoaded(
       _LibraryPrefix prefix,
       int location,
       Object src_value,
       _Type dst_type,
       String dst_name,
       String bound_error_msg) {
     if (!prefix.isLoaded()) {
       _throwNew(location, src_value, dst_type, dst_name, bound_error_msg);
     }
   }

   String toString() => super.message;
 }

 class _CastError extends Error implements CastError {
   _CastError._create(this._url, this._line, this._column, this._errorMsg);

   // A CastError is allocated by TypeError._throwNew() when dst_name equals
   // Symbols::InTypeCast().

   String toString() => _errorMsg;

   // Fields _url, _line, and _column are only used for debugging purposes.
   final String _url;
   final int _line;
   final int _column;
   final String _errorMsg;
 }

 @patch
 class FallThroughError {
   FallThroughError._create(this._url, this._line);

   static _throwNew(int case_clause_pos) native "FallThroughError_throwNew";

   @patch
   String toString() {
     return "'$_url': Switch case fall-through at line $_line.";
   }

   // These new fields cannot be declared final, because a constructor exists
   // in the original version of this patched class.
   String _url;
   int _line;
 }

 class _InternalError {
   const _InternalError(this._msg);
   String toString() => "InternalError: '${_msg}'";
   final String _msg;
 }

 @patch
 class UnsupportedError {
   static _throwNew(String msg) {
     throw new UnsupportedError(msg);
   }
 }

 @patch
 class CyclicInitializationError {
   static _throwNew(String variableName) {
     throw new CyclicInitializationError(variableName);
   }
 }

 @patch
 class AbstractClassInstantiationError {
   AbstractClassInstantiationError._create(
       this._className, this._url, this._line);

   static _throwNew(int case_clause_pos, String className)
       native "AbstractClassInstantiationError_throwNew";

   @patch
   String toString() {
     return "Cannot instantiate abstract class $_className: "
         "_url '$_url' line $_line";
   }

   // These new fields cannot be declared final, because a constructor exists
   // in the original version of this patched class.
   String _url;
   int _line;
 }

 @patch
 class NoSuchMethodError {
   // The compiler emits a call to _throwNew when it cannot resolve a static
   // method at compile time. The receiver is actually the literal class of the
   // unresolved method.
   static void _throwNew(Object receiver, String memberName, int invocation_type,
       List arguments, List argumentNames, List existingArgumentNames) {
     int numNamedArguments = argumentNames == null ? 0 : argumentNames.length;
     int numPositionalArguments = arguments == null ? 0 : arguments.length;
     numPositionalArguments -= numNamedArguments;
     List positionalArguments;
     if (numPositionalArguments > 0) {
       // TODO(srdjan): Unresolvable static methods sometimes do not provide the
       // arguments, because the arguments are evaluated but not passed to the
       // throwing stub (see EffectGraphVisitor::BuildThrowNoSuchMethodError and
       // Parser::ThrowNoSuchMethodError)). There is no way to distinguish the
       // case of no arguments from the case of the arguments not being passed
       // in here, though. See https://github.com/dart-lang/sdk/issues/27572
       positionalArguments = arguments.sublist(0, numPositionalArguments);
     }
     Map<Symbol, dynamic> namedArguments = new Map<Symbol, dynamic>();
     for (int i = 0; i < numNamedArguments; i++) {
       var arg_value = arguments[numPositionalArguments + i];
       namedArguments[new Symbol(argumentNames[i])] = arg_value;
     }
     throw new NoSuchMethodError._withType(
         receiver,
         new Symbol(memberName),
         invocation_type,
         positionalArguments,
         namedArguments,
         existingArgumentNames);
   }

   static void _throwNewIfNotLoaded(
       _LibraryPrefix prefix,
       Object receiver,
       String memberName,
       int invocation_type,
       List arguments,
       List argumentNames,
       List existingArgumentNames) {
     if (!prefix.isLoaded()) {
       _throwNew(receiver, memberName, invocation_type, arguments, argumentNames,
           existingArgumentNames);
     }
   }

   // Remember the type from the invocation mirror or static compilation
   // analysis when thrown directly with _throwNew. A negative value means
   // that no information is available.
   final int _invocation_type;

   @patch
   NoSuchMethodError(Object receiver, Symbol memberName,
       List positionalArguments, Map<Symbol, dynamic> namedArguments,
       [List existingArgumentNames = null])
       : _receiver = receiver,
         _memberName = memberName,
         _arguments = positionalArguments,
         _namedArguments = namedArguments,
         _existingArgumentNames = existingArgumentNames,
         _invocation_type = -1;

   // This constructor seems to be called with either strings or
   // values read from another NoSuchMethodError.
   NoSuchMethodError._withType(
       this._receiver,
       /*String|Symbol*/ memberName,
       this._invocation_type,
       this._arguments,
       Map<dynamic, dynamic> namedArguments,
       [List existingArgumentNames = null])
       : this._memberName =
             (memberName is String) ? new Symbol(memberName) : memberName,
         this._namedArguments = (namedArguments == null)
             ? null
             : new Map<Symbol, dynamic>.fromIterable(namedArguments.keys,
                 key: (k) => (k is String) ? new Symbol(k) : k,
                 value: (k) => namedArguments[k]),
         this._existingArgumentNames = existingArgumentNames;

   @patch
   String toString() {
     var level = (_invocation_type >> _InvocationMirror._CALL_SHIFT) &
         _InvocationMirror._CALL_MASK;
     var type = _invocation_type & _InvocationMirror._TYPE_MASK;
     String memberName = (_memberName == null)
         ? ""
         : internal.Symbol.getUnmangledName(_memberName);

     if (type == _InvocationMirror._LOCAL_VAR) {
       return "NoSuchMethodError: Cannot assign to final variable '$memberName'";
     }

     StringBuffer arguments = new StringBuffer();
     int argumentCount = 0;
     if (_arguments != null) {
       for (; argumentCount < _arguments.length; argumentCount++) {
         if (argumentCount > 0) {
           arguments.write(", ");
         }
         arguments.write(Error.safeToString(_arguments[argumentCount]));
       }
     }
     if (_namedArguments != null) {
       _namedArguments.forEach((Symbol key, var value) {
         if (argumentCount > 0) {
           arguments.write(", ");
         }
         arguments.write(internal.Symbol.getUnmangledName(key));
         arguments.write(": ");
         arguments.write(Error.safeToString(value));
         argumentCount++;
       });
     }
     bool args_mismatch = _existingArgumentNames != null;
     String args_message = args_mismatch ? " with matching arguments" : "";

     String type_str;
     if (type >= 0 && type < 5) {
       type_str = (const [
         "method",
         "getter",
         "setter",
         "getter or setter",
         "variable"
       ])[type];
     }

     StringBuffer msg_buf = new StringBuffer("NoSuchMethodError: ");
     bool is_type_call = false;
     switch (level) {
       case _InvocationMirror._DYNAMIC:
         {
           if (_receiver == null) {
             if (args_mismatch) {
               msg_buf.writeln("The null object does not have a $type_str "
                   "'$memberName'$args_message.");
             } else {
               msg_buf
                   .writeln("The $type_str '$memberName' was called on null.");
             }
           } else {
             if (_receiver is _Closure) {
               msg_buf.writeln("Closure call with mismatched arguments: "
                   "function '$memberName'");
             } else if (_receiver is _Type && memberName == "call") {
               is_type_call = true;
               String name = _receiver.toString();
               msg_buf.writeln("Attempted to use type '$name' as a function. "
                   "Since types do not define a method 'call', this is not "
                   "possible. Did you intend to call the $name constructor and "
                   "forget the 'new' operator?");
             } else {
               msg_buf
                   .writeln("Class '${_receiver.runtimeType}' has no instance "
                       "$type_str '$memberName'$args_message.");
             }
           }
           break;
         }
       case _InvocationMirror._SUPER:
         {
           msg_buf.writeln("Super class of class '${_receiver.runtimeType}' has "
               "no instance $type_str '$memberName'$args_message.");
           memberName = "super.$memberName";
           break;
         }
       case _InvocationMirror._STATIC:
         {
           msg_buf.writeln("No static $type_str '$memberName'$args_message "
               "declared in class '$_receiver'.");
           break;
         }
       case _InvocationMirror._CONSTRUCTOR:
         {
           msg_buf.writeln("No constructor '$memberName'$args_message declared "
               "in class '$_receiver'.");
           memberName = "new $memberName";
           break;
         }
       case _InvocationMirror._TOP_LEVEL:
         {
           msg_buf.writeln("No top-level $type_str '$memberName'$args_message "
               "declared.");
           break;
         }
     }

     if (level == _InvocationMirror._TOP_LEVEL) {
       msg_buf.writeln("Receiver: top-level");
     } else {
       msg_buf.writeln("Receiver: ${Error.safeToString(_receiver)}");
     }

     if (type == _InvocationMirror._METHOD) {
       String m = is_type_call ? "$_receiver" : "$memberName";
       msg_buf.write("Tried calling: $m($arguments)");
     } else if (argumentCount == 0) {
       msg_buf.write("Tried calling: $memberName");
     } else if (type == _InvocationMirror._SETTER) {
       msg_buf.write("Tried calling: $memberName$arguments");
     } else {
       msg_buf.write("Tried calling: $memberName = $arguments");
     }

     if (args_mismatch) {
       StringBuffer formalParameters = new StringBuffer();
       for (int i = 0; i < _existingArgumentNames.length; i++) {
         if (i > 0) {
           formalParameters.write(", ");
         }
         formalParameters.write(_existingArgumentNames[i]);
       }
       msg_buf.write("\nFound: $memberName($formalParameters)");
     }

     return msg_buf.toString();
   }
 }

 class _CompileTimeError extends Error {
   final String _errorMsg;
   _CompileTimeError(this._errorMsg);
   String toString() => _errorMsg;
 }

 dynamic _classRangeAssert(int position, dynamic instance, _Type type, int cid,
     int lowerLimit, int upperLimit) {
   if ((cid < lowerLimit || cid > upperLimit) && instance != null) {
     _TypeError._throwNew(position, instance, type, " in type cast", null);
   }

   return instance;
 }

 dynamic _classIdEqualsAssert(
     int position, dynamic instance, _Type type, int cid, int otherCid) {
   if (cid != otherCid && instance != null) {
     _TypeError._throwNew(position, instance, type, " in type cast", null);
   }

   return instance;
 }
	// Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file
	// for details. All rights reserved. Use of this source code is governed by a
	// BSD-style license that can be found in the LICENSE file.

	@patch
	class Error {
	@patch
	static String _objectToString(Object object) {
	return Object._toString(object);
	}

	@patch
	static String _stringToSafeString(String string) {
	return JSON.encode(string);
	}

	@patch
	StackTrace get stackTrace => _stackTrace;

	StackTrace _stackTrace;
	}

	class _AssertionError extends Error implements AssertionError {
	_AssertionError._create(
	this._failedAssertion, this._url, this._line, this._column, this.message);

	// AssertionError_throwNew in errors.cc fishes the assertion source code
	// out of the script. It expects a Dart stack frame from class
	// _AssertionError. Thus we need a Dart stub that calls the native code.
	static _throwNew(int assertionStart, int assertionEnd, Object message) {
	_doThrowNew(assertionStart, assertionEnd, message);
	}

	static _doThrowNew(int assertionStart, int assertionEnd, Object message)
	native "AssertionError_throwNew";

	static _evaluateAssertion(condition) {
	if (identical(condition, true) \|\| identical(condition, false)) {
	return condition;
	}
	if (condition is _Closure) {
	return condition();
	}
	if (condition is Function) {
	condition = condition();
	}
	return condition;
	}

	String get _messageString {
	if (message == null) return "is not true.";
	if (message is String) return message;
	return Error.safeToString(message);
	}

	String toString() {
	if (_url == null) {
	if (message == null) return _failedAssertion;
	return "'$_failedAssertion': $_messageString";
	}
	var columnInfo = "";
	if (_column > 0) {
	// Only add column information if it is valid.
	columnInfo = " pos $_column";
	}
	return "'$_url': Failed assertion: line $_line$columnInfo: "
	"'$_failedAssertion': $_messageString";
	}

	final String _failedAssertion;
	final String _url;
	final int _line;
	final int _column;
	final Object message;
	}

	class _TypeError extends _AssertionError implements TypeError {
	_TypeError._create(String url, int line, int column, String errorMsg)
	: super._create("is assignable", url, line, column, errorMsg);

	static _throwNew(int location, Object src_value, _Type dst_type,
	String dst_name, String bound_error_msg) native "TypeError_throwNew";

	static _throwNewIfNotLoaded(
	_LibraryPrefix prefix,
	int location,
	Object src_value,
	_Type dst_type,
	String dst_name,
	String bound_error_msg) {
	if (!prefix.isLoaded()) {
	_throwNew(location, src_value, dst_type, dst_name, bound_error_msg);
	}
	}

	String toString() => super.message;
	}

	class _CastError extends Error implements CastError {
	_CastError._create(this._url, this._line, this._column, this._errorMsg);

	// A CastError is allocated by TypeError._throwNew() when dst_name equals
	// Symbols::InTypeCast().

	String toString() => _errorMsg;

	// Fields _url, _line, and _column are only used for debugging purposes.
	final String _url;
	final int _line;
	final int _column;
	final String _errorMsg;
	}

	@patch
	class FallThroughError {
	FallThroughError._create(this._url, this._line);

	static _throwNew(int case_clause_pos) native "FallThroughError_throwNew";

	@patch
	String toString() {
	return "'$_url': Switch case fall-through at line $_line.";
	}

	// These new fields cannot be declared final, because a constructor exists
	// in the original version of this patched class.
	String _url;
	int _line;
	}

	class _InternalError {
	const _InternalError(this._msg);
	String toString() => "InternalError: '${_msg}'";
	final String _msg;
	}

	@patch
	class UnsupportedError {
	static _throwNew(String msg) {
	throw new UnsupportedError(msg);
	}
	}

	@patch
	class CyclicInitializationError {
	static _throwNew(String variableName) {
	throw new CyclicInitializationError(variableName);
	}
	}

	@patch
	class AbstractClassInstantiationError {
	AbstractClassInstantiationError._create(
	this._className, this._url, this._line);

	static _throwNew(int case_clause_pos, String className)
	native "AbstractClassInstantiationError_throwNew";

	@patch
	String toString() {
	return "Cannot instantiate abstract class $_className: "
	"_url '$_url' line $_line";
	}

	// These new fields cannot be declared final, because a constructor exists
	// in the original version of this patched class.
	String _url;
	int _line;
	}

	@patch
	class NoSuchMethodError {
	// The compiler emits a call to _throwNew when it cannot resolve a static
	// method at compile time. The receiver is actually the literal class of the
	// unresolved method.
	static void _throwNew(Object receiver, String memberName, int invocation_type,
	List arguments, List argumentNames, List existingArgumentNames) {
	int numNamedArguments = argumentNames == null ? 0 : argumentNames.length;
	int numPositionalArguments = arguments == null ? 0 : arguments.length;
	numPositionalArguments -= numNamedArguments;
	List positionalArguments;
	if (numPositionalArguments > 0) {
	// TODO(srdjan): Unresolvable static methods sometimes do not provide the
	// arguments, because the arguments are evaluated but not passed to the
	// throwing stub (see EffectGraphVisitor::BuildThrowNoSuchMethodError and
	// Parser::ThrowNoSuchMethodError)). There is no way to distinguish the
	// case of no arguments from the case of the arguments not being passed
	// in here, though. See https://github.com/dart-lang/sdk/issues/27572
	positionalArguments = arguments.sublist(0, numPositionalArguments);
	}
	Map<Symbol, dynamic> namedArguments = new Map<Symbol, dynamic>();
	for (int i = 0; i < numNamedArguments; i++) {
	var arg_value = arguments[numPositionalArguments + i];
	namedArguments[new Symbol(argumentNames[i])] = arg_value;
	}
	throw new NoSuchMethodError._withType(
	receiver,
	new Symbol(memberName),
	invocation_type,
	positionalArguments,
	namedArguments,
	existingArgumentNames);
	}

	static void _throwNewIfNotLoaded(
	_LibraryPrefix prefix,
	Object receiver,
	String memberName,
	int invocation_type,
	List arguments,
	List argumentNames,
	List existingArgumentNames) {
	if (!prefix.isLoaded()) {
	_throwNew(receiver, memberName, invocation_type, arguments, argumentNames,
	existingArgumentNames);
	}
	}

	// Remember the type from the invocation mirror or static compilation
	// analysis when thrown directly with _throwNew. A negative value means
	// that no information is available.
	final int _invocation_type;

	@patch
	NoSuchMethodError(Object receiver, Symbol memberName,
	List positionalArguments, Map<Symbol, dynamic> namedArguments,
	[List existingArgumentNames = null])
	: _receiver = receiver,
	_memberName = memberName,
	_arguments = positionalArguments,
	_namedArguments = namedArguments,
	_existingArgumentNames = existingArgumentNames,
	_invocation_type = -1;

	// This constructor seems to be called with either strings or
	// values read from another NoSuchMethodError.
	NoSuchMethodError._withType(
	this._receiver,
	/String\|Symbol/ memberName,
	this._invocation_type,
	this._arguments,
	Map<dynamic, dynamic> namedArguments,
	[List existingArgumentNames = null])
	: this._memberName =
	(memberName is String) ? new Symbol(memberName) : memberName,
	this._namedArguments = (namedArguments == null)
	? null
	: new Map<Symbol, dynamic>.fromIterable(namedArguments.keys,
	key: (k) => (k is String) ? new Symbol(k) : k,
	value: (k) => namedArguments[k]),
	this._existingArgumentNames = existingArgumentNames;

	@patch
	String toString() {
	var level = (_invocation_type >> _InvocationMirror._CALL_SHIFT) &
	_InvocationMirror._CALL_MASK;
	var type = _invocation_type & _InvocationMirror._TYPE_MASK;
	String memberName = (_memberName == null)
	? ""
	: internal.Symbol.getUnmangledName(_memberName);

	if (type == _InvocationMirror._LOCAL_VAR) {
	return "NoSuchMethodError: Cannot assign to final variable '$memberName'";
	}

	StringBuffer arguments = new StringBuffer();
	int argumentCount = 0;
	if (_arguments != null) {
	for (; argumentCount < _arguments.length; argumentCount++) {
	if (argumentCount > 0) {
	arguments.write(", ");
	}
	arguments.write(Error.safeToString(_arguments[argumentCount]));
	}
	}
	if (_namedArguments != null) {
	_namedArguments.forEach((Symbol key, var value) {
	if (argumentCount > 0) {
	arguments.write(", ");
	}
	arguments.write(internal.Symbol.getUnmangledName(key));
	arguments.write(": ");
	arguments.write(Error.safeToString(value));
	argumentCount++;
	});
	}
	bool args_mismatch = _existingArgumentNames != null;
	String args_message = args_mismatch ? " with matching arguments" : "";

	String type_str;
	if (type >= 0 && type < 5) {
	type_str = (const [
	"method",
	"getter",
	"setter",
	"getter or setter",
	"variable"
	])[type];
	}

	StringBuffer msg_buf = new StringBuffer("NoSuchMethodError: ");
	bool is_type_call = false;
	switch (level) {
	case _InvocationMirror._DYNAMIC:
	{
	if (_receiver == null) {
	if (args_mismatch) {
	msg_buf.writeln("The null object does not have a $type_str "
	"'$memberName'$args_message.");
	} else {
	msg_buf
	.writeln("The $type_str '$memberName' was called on null.");
	}
	} else {
	if (_receiver is _Closure) {
	msg_buf.writeln("Closure call with mismatched arguments: "
	"function '$memberName'");
	} else if (_receiver is _Type && memberName == "call") {
	is_type_call = true;
	String name = _receiver.toString();
	msg_buf.writeln("Attempted to use type '$name' as a function. "
	"Since types do not define a method 'call', this is not "
	"possible. Did you intend to call the $name constructor and "
	"forget the 'new' operator?");
	} else {
	msg_buf
	.writeln("Class '${_receiver.runtimeType}' has no instance "
	"$type_str '$memberName'$args_message.");
	}
	}
	break;
	}
	case _InvocationMirror._SUPER:
	{
	msg_buf.writeln("Super class of class '${_receiver.runtimeType}' has "
	"no instance $type_str '$memberName'$args_message.");
	memberName = "super.$memberName";
	break;
	}
	case _InvocationMirror._STATIC:
	{
	msg_buf.writeln("No static $type_str '$memberName'$args_message "
	"declared in class '$_receiver'.");
	break;
	}
	case _InvocationMirror._CONSTRUCTOR:
	{
	msg_buf.writeln("No constructor '$memberName'$args_message declared "
	"in class '$_receiver'.");
	memberName = "new $memberName";
	break;
	}
	case _InvocationMirror._TOP_LEVEL:
	{
	msg_buf.writeln("No top-level $type_str '$memberName'$args_message "
	"declared.");
	break;
	}
	}

	if (level == _InvocationMirror._TOP_LEVEL) {
	msg_buf.writeln("Receiver: top-level");
	} else {
	msg_buf.writeln("Receiver: ${Error.safeToString(_receiver)}");
	}

	if (type == _InvocationMirror._METHOD) {
	String m = is_type_call ? "$_receiver" : "$memberName";
	msg_buf.write("Tried calling: $m($arguments)");
	} else if (argumentCount == 0) {
	msg_buf.write("Tried calling: $memberName");
	} else if (type == _InvocationMirror._SETTER) {
	msg_buf.write("Tried calling: $memberName$arguments");
	} else {
	msg_buf.write("Tried calling: $memberName = $arguments");
	}

	if (args_mismatch) {
	StringBuffer formalParameters = new StringBuffer();
	for (int i = 0; i < _existingArgumentNames.length; i++) {
	if (i > 0) {
	formalParameters.write(", ");
	}
	formalParameters.write(_existingArgumentNames[i]);
	}
	msg_buf.write("\nFound: $memberName($formalParameters)");
	}

	return msg_buf.toString();
	}
	}

	class _CompileTimeError extends Error {
	final String _errorMsg;
	_CompileTimeError(this._errorMsg);
	String toString() => _errorMsg;
	}

	dynamic _classRangeAssert(int position, dynamic instance, _Type type, int cid,
	int lowerLimit, int upperLimit) {
	if ((cid < lowerLimit \|\| cid > upperLimit) && instance != null) {
	_TypeError._throwNew(position, instance, type, " in type cast", null);
	}

	return instance;
	}

	dynamic _classIdEqualsAssert(
	int position, dynamic instance, _Type type, int cid, int otherCid) {
	if (cid != otherCid && instance != null) {
	_TypeError._throwNew(position, instance, type, " in type cast", null);
	}

	return instance;
	}