runtime/lib/string.cc - sdk.git - Git at Google

 // Copyright (c) 2011, 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.

 #include "vm/bootstrap_natives.h"

 #include "include/dart_api.h"
 #include "vm/exceptions.h"
 #include "vm/dart_api_impl.h"
 #include "vm/isolate.h"
 #include "vm/native_entry.h"
 #include "vm/object.h"
 #include "vm/symbols.h"
 #include "vm/unicode.h"

 namespace dart {

 DEFINE_NATIVE_ENTRY(String_fromEnvironment, 3) {
   GET_NON_NULL_NATIVE_ARGUMENT(String, name, arguments->NativeArgAt(1));
   GET_NATIVE_ARGUMENT(String, default_value, arguments->NativeArgAt(2));
   // Call the embedder to supply us with the environment.
   Api::Scope api_scope(isolate);
   Dart_EnvironmentCallback callback = isolate->environment_callback();
   if (callback != NULL) {
     Dart_Handle result = callback(Api::NewHandle(isolate, name.raw()));
     if (Dart_IsString(result)) {
       const Object& value =
           Object::Handle(isolate, Api::UnwrapHandle(result));
       return Symbols::New(String::Cast(value));
     } else if (Dart_IsError(result)) {
       const Object& error =
           Object::Handle(isolate, Api::UnwrapHandle(result));
       Exceptions::ThrowArgumentError(
           String::Handle(
               String::New(Error::Cast(error).ToErrorCString())));
     } else if (!Dart_IsNull(result)) {
       Exceptions::ThrowArgumentError(
           String::Handle(String::New("Illegal environment value")));
     }
   }
   return default_value.raw();
 }


 DEFINE_NATIVE_ENTRY(StringBase_createFromCodePoints, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(Instance, list, arguments->NativeArgAt(0));
   if (!list.IsGrowableObjectArray() && !list.IsArray()) {
     Exceptions::ThrowArgumentError(list);
   }

   Array& a = Array::Handle();
   intptr_t array_len;
   if (list.IsGrowableObjectArray()) {
     const GrowableObjectArray& growableArray = GrowableObjectArray::Cast(list);
     a ^= growableArray.data();
     array_len = growableArray.Length();
   } else {
     a ^= Array::Cast(list).raw();
     array_len = a.Length();
   }

   Zone* zone = isolate->current_zone();

   // Unbox the array and determine the maximum element width.
   bool is_one_byte_string = true;
   intptr_t utf16_len = array_len;
   int32_t* utf32_array = zone->Alloc<int32_t>(array_len);
   Instance& index_object = Instance::Handle(isolate);
   for (intptr_t i = 0; i < array_len; i++) {
     index_object ^= a.At(i);
     if (!index_object.IsSmi()) {
       Exceptions::ThrowArgumentError(index_object);
     }
     intptr_t value = Smi::Cast(index_object).Value();
     if (Utf::IsOutOfRange(value)) {
       Exceptions::ThrowByType(Exceptions::kArgument, Object::empty_array());
       UNREACHABLE();
     }
     // Now it is safe to cast the value.
     int32_t value32 = static_cast<int32_t>(value);
     if (!Utf::IsLatin1(value32)) {
       is_one_byte_string = false;
       if (Utf::IsSupplementary(value32)) {
         utf16_len += 1;
       }
     }
     utf32_array[i] = value32;
   }
   if (is_one_byte_string) {
     return OneByteString::New(utf32_array, array_len, Heap::kNew);
   }
   return TwoByteString::New(utf16_len, utf32_array, array_len, Heap::kNew);
 }


 DEFINE_NATIVE_ENTRY(StringBase_substringUnchecked, 3) {
   const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Smi, start_obj, arguments->NativeArgAt(1));
   GET_NON_NULL_NATIVE_ARGUMENT(Smi, end_obj, arguments->NativeArgAt(2));

   intptr_t start = start_obj.Value();
   intptr_t end = end_obj.Value();
   return String::SubString(receiver, start, (end - start));
 }


 DEFINE_NATIVE_ENTRY(OneByteString_substringUnchecked, 3) {
   const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
   ASSERT(receiver.IsOneByteString());
   GET_NON_NULL_NATIVE_ARGUMENT(Smi, start_obj, arguments->NativeArgAt(1));
   GET_NON_NULL_NATIVE_ARGUMENT(Smi, end_obj, arguments->NativeArgAt(2));

   const intptr_t start = start_obj.Value();
   const intptr_t end = end_obj.Value();
   return OneByteString::New(receiver, start, end - start, Heap::kNew);
 }


 // This is high-performance code.
 DEFINE_NATIVE_ENTRY(OneByteString_splitWithCharCode, 2) {
   const String& receiver = String::CheckedHandle(isolate,
                                                  arguments->NativeArgAt(0));
   ASSERT(receiver.IsOneByteString());
   GET_NON_NULL_NATIVE_ARGUMENT(Smi, smi_split_code, arguments->NativeArgAt(1));
   const intptr_t len = receiver.Length();
   const intptr_t split_code = smi_split_code.Value();
   const GrowableObjectArray& result = GrowableObjectArray::Handle(
       isolate,
       GrowableObjectArray::New(16, Heap::kNew));
   String& str = String::Handle(isolate);
   intptr_t start = 0;
   intptr_t i = 0;
   for (; i < len; i++) {
     if (split_code == OneByteString::CharAt(receiver, i)) {
       str = OneByteString::SubStringUnchecked(receiver,
                                               start,
                                               (i - start),
                                               Heap::kNew);
       result.Add(str);
       start = i + 1;
     }
   }
   str = OneByteString::SubStringUnchecked(receiver,
                                           start,
                                           (i - start),
                                           Heap::kNew);
   result.Add(str);
   return result.raw();
 }


 DEFINE_NATIVE_ENTRY(OneByteString_allocate, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(Smi, length_obj, arguments->NativeArgAt(0));
   return OneByteString::New(length_obj.Value(), Heap::kNew);
 }


 DEFINE_NATIVE_ENTRY(OneByteString_allocateFromOneByteList, 1) {
   Instance& list = Instance::CheckedHandle(arguments->NativeArgAt(0));
   if (list.IsTypedData()) {
     const TypedData& array = TypedData::Cast(list);
     intptr_t length = array.LengthInBytes();
     return OneByteString::New(array, 0, length);
   } else if (list.IsExternalTypedData()) {
     const ExternalTypedData& array = ExternalTypedData::Cast(list);
     intptr_t length = array.LengthInBytes();
     return OneByteString::New(array, 0, length);
   } else if (RawObject::IsTypedDataViewClassId(list.GetClassId())) {
     const Instance& view = Instance::Cast(list);
     intptr_t length = Smi::Value(TypedDataView::Length(view));
     const Instance& data_obj = Instance::Handle(TypedDataView::Data(view));
     intptr_t data_offset = Smi::Value(TypedDataView::OffsetInBytes(view));
     if (data_obj.IsTypedData()) {
       const TypedData& array = TypedData::Cast(data_obj);
       return OneByteString::New(array, data_offset, length);
     } else if (data_obj.IsExternalTypedData()) {
       const ExternalTypedData& array = ExternalTypedData::Cast(data_obj);
       return OneByteString::New(array, data_offset, length);
     }
   } else if (list.IsArray()) {
     const Array& array = Array::Cast(list);
     intptr_t length = array.Length();
     String& string = String::Handle(OneByteString::New(length, Heap::kNew));
     for (int i = 0; i < length; i++) {
       intptr_t value = Smi::Value(reinterpret_cast<RawSmi*>(array.At(i)));
       OneByteString::SetCharAt(string, i, value);
     }
     return string.raw();
   } else if (list.IsGrowableObjectArray()) {
     const GrowableObjectArray& array = GrowableObjectArray::Cast(list);
     intptr_t length = array.Length();
     String& string = String::Handle(OneByteString::New(length, Heap::kNew));
     for (int i = 0; i < length; i++) {
       intptr_t value = Smi::Value(reinterpret_cast<RawSmi*>(array.At(i)));
       OneByteString::SetCharAt(string, i, value);
     }
     return string.raw();
   }
   UNREACHABLE();
   return Object::null();
 }


 DEFINE_NATIVE_ENTRY(OneByteString_setAt, 3) {
   GET_NON_NULL_NATIVE_ARGUMENT(String, receiver, arguments->NativeArgAt(0));
   ASSERT(receiver.IsOneByteString());
   GET_NON_NULL_NATIVE_ARGUMENT(Smi, index_obj, arguments->NativeArgAt(1));
   GET_NON_NULL_NATIVE_ARGUMENT(Smi, code_point_obj, arguments->NativeArgAt(2));
   ASSERT((0 <= code_point_obj.Value()) && (code_point_obj.Value() <= 0xFF));
   OneByteString::SetCharAt(receiver, index_obj.Value(), code_point_obj.Value());
   return Object::null();
 }


 DEFINE_NATIVE_ENTRY(ExternalOneByteString_getCid, 0) {
   return Smi::New(kExternalOneByteStringCid);
 }


 DEFINE_NATIVE_ENTRY(String_getHashCode, 1) {
   const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
   intptr_t hash_val = receiver.Hash();
   ASSERT(hash_val > 0);
   ASSERT(Smi::IsValid(hash_val));
   return Smi::New(hash_val);
 }


 DEFINE_NATIVE_ENTRY(String_getLength, 1) {
   const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
   return Smi::New(receiver.Length());
 }


 static int32_t StringValueAt(const String& str, const Integer& index) {
   if (index.IsSmi()) {
     const Smi& smi = Smi::Cast(index);
     intptr_t index = smi.Value();
     if ((index < 0) || (index >= str.Length())) {
       const Array& args = Array::Handle(Array::New(1));
       args.SetAt(0, smi);
       Exceptions::ThrowByType(Exceptions::kRange, args);
     }
     return str.CharAt(index);
   } else {
     // An index larger than Smi is always illegal.
     const Array& args = Array::Handle(Array::New(1));
     args.SetAt(0, index);
     Exceptions::ThrowByType(Exceptions::kRange, args);
     return 0;
   }
 }


 DEFINE_NATIVE_ENTRY(String_charAt, 2) {
   const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Integer, index, arguments->NativeArgAt(1));
   uint32_t value = StringValueAt(receiver, index);
   ASSERT(value <= 0x10FFFF);
   return Symbols::FromCharCode(value);
 }


 DEFINE_NATIVE_ENTRY(String_codeUnitAt, 2) {
   const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Integer, index, arguments->NativeArgAt(1));

   int32_t value = StringValueAt(receiver, index);
   ASSERT(value >= 0);
   ASSERT(value <= 0xFFFF);
   return Smi::New(value);
 }


 DEFINE_NATIVE_ENTRY(String_concat, 2) {
   const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(String, b, arguments->NativeArgAt(1));
   return String::Concat(receiver, b);
 }


 DEFINE_NATIVE_ENTRY(String_toLowerCase, 1) {
   const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
   ASSERT(!receiver.IsNull());
   return String::ToLowerCase(receiver);
 }


 DEFINE_NATIVE_ENTRY(String_toUpperCase, 1) {
   const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
   ASSERT(!receiver.IsNull());
   return String::ToUpperCase(receiver);
 }


 DEFINE_NATIVE_ENTRY(String_concatRange, 3) {
   GET_NON_NULL_NATIVE_ARGUMENT(Instance, argument, arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Smi, start, arguments->NativeArgAt(1));
   GET_NON_NULL_NATIVE_ARGUMENT(Smi, end, arguments->NativeArgAt(2));
   const intptr_t start_ix = start.Value();
   const intptr_t end_ix = end.Value();
   if (start_ix < 0) {
     Exceptions::ThrowArgumentError(start);
   }
   Array& strings = Array::Handle();
   intptr_t length = -1;
   if (argument.IsArray()) {
     strings ^= argument.raw();
     length = strings.Length();
   } else if (argument.IsGrowableObjectArray()) {
     const GrowableObjectArray& g_array = GrowableObjectArray::Cast(argument);
     strings = g_array.data();
     length =  g_array.Length();
   } else {
     Exceptions::ThrowArgumentError(argument);
   }
   if (end_ix > length) {
     Exceptions::ThrowArgumentError(end);
   }
 #if defined(DEBUG)
   // Check that the array contains strings.
   Instance& elem = Instance::Handle();
   for (intptr_t i = start_ix; i < end_ix; i++) {
     elem ^= strings.At(i);
     ASSERT(elem.IsString());
   }
 #endif
   return String::ConcatAllRange(strings, start_ix, end_ix, Heap::kNew);
 }


 DEFINE_NATIVE_ENTRY(StringBuffer_createStringFromUint16Array, 3) {
   GET_NON_NULL_NATIVE_ARGUMENT(TypedData, codeUnits, arguments->NativeArgAt(0));
   GET_NON_NULL_NATIVE_ARGUMENT(Smi, length, arguments->NativeArgAt(1));
   GET_NON_NULL_NATIVE_ARGUMENT(Bool, isLatin1, arguments->NativeArgAt(2));
   intptr_t array_length = codeUnits.Length();
   intptr_t length_value = length.Value();
   if (length_value < 0 || length_value > array_length) {
     const Array& args = Array::Handle(Array::New(1));
     args.SetAt(0, length);
     Exceptions::ThrowByType(Exceptions::kRange, args);
   }
   const String& result = isLatin1.value()
       ? String::Handle(OneByteString::New(length_value, Heap::kNew))
       : String::Handle(TwoByteString::New(length_value, Heap::kNew));
   NoGCScope no_gc;

   uint16_t* data_position = reinterpret_cast<uint16_t*>(codeUnits.DataAddr(0));
   String::Copy(result, 0, data_position, length_value);
   return result.raw();
 }

 }  // namespace dart
	// Copyright (c) 2011, 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.

	#include "vm/bootstrap_natives.h"

	#include "include/dart_api.h"
	#include "vm/exceptions.h"
	#include "vm/dart_api_impl.h"
	#include "vm/isolate.h"
	#include "vm/native_entry.h"
	#include "vm/object.h"
	#include "vm/symbols.h"
	#include "vm/unicode.h"

	namespace dart {

	DEFINE_NATIVE_ENTRY(String_fromEnvironment, 3) {
	GET_NON_NULL_NATIVE_ARGUMENT(String, name, arguments->NativeArgAt(1));
	GET_NATIVE_ARGUMENT(String, default_value, arguments->NativeArgAt(2));
	// Call the embedder to supply us with the environment.
	Api::Scope api_scope(isolate);
	Dart_EnvironmentCallback callback = isolate->environment_callback();
	if (callback != NULL) {
	Dart_Handle result = callback(Api::NewHandle(isolate, name.raw()));
	if (Dart_IsString(result)) {
	const Object& value =
	Object::Handle(isolate, Api::UnwrapHandle(result));
	return Symbols::New(String::Cast(value));
	} else if (Dart_IsError(result)) {
	const Object& error =
	Object::Handle(isolate, Api::UnwrapHandle(result));
	Exceptions::ThrowArgumentError(
	String::Handle(
	String::New(Error::Cast(error).ToErrorCString())));
	} else if (!Dart_IsNull(result)) {
	Exceptions::ThrowArgumentError(
	String::Handle(String::New("Illegal environment value")));
	}
	}
	return default_value.raw();
	}


	DEFINE_NATIVE_ENTRY(StringBase_createFromCodePoints, 1) {
	GET_NON_NULL_NATIVE_ARGUMENT(Instance, list, arguments->NativeArgAt(0));
	if (!list.IsGrowableObjectArray() && !list.IsArray()) {
	Exceptions::ThrowArgumentError(list);
	}

	Array& a = Array::Handle();
	intptr_t array_len;
	if (list.IsGrowableObjectArray()) {
	const GrowableObjectArray& growableArray = GrowableObjectArray::Cast(list);
	a ^= growableArray.data();
	array_len = growableArray.Length();
	} else {
	a ^= Array::Cast(list).raw();
	array_len = a.Length();
	}

	Zone* zone = isolate->current_zone();

	// Unbox the array and determine the maximum element width.
	bool is_one_byte_string = true;
	intptr_t utf16_len = array_len;
	int32_t* utf32_array = zone->Alloc<int32_t>(array_len);
	Instance& index_object = Instance::Handle(isolate);
	for (intptr_t i = 0; i < array_len; i++) {
	index_object ^= a.At(i);
	if (!index_object.IsSmi()) {
	Exceptions::ThrowArgumentError(index_object);
	}
	intptr_t value = Smi::Cast(index_object).Value();
	if (Utf::IsOutOfRange(value)) {
	Exceptions::ThrowByType(Exceptions::kArgument, Object::empty_array());
	UNREACHABLE();
	}
	// Now it is safe to cast the value.
	int32_t value32 = static_cast<int32_t>(value);
	if (!Utf::IsLatin1(value32)) {
	is_one_byte_string = false;
	if (Utf::IsSupplementary(value32)) {
	utf16_len += 1;
	}
	}
	utf32_array[i] = value32;
	}
	if (is_one_byte_string) {
	return OneByteString::New(utf32_array, array_len, Heap::kNew);
	}
	return TwoByteString::New(utf16_len, utf32_array, array_len, Heap::kNew);
	}


	DEFINE_NATIVE_ENTRY(StringBase_substringUnchecked, 3) {
	const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
	GET_NON_NULL_NATIVE_ARGUMENT(Smi, start_obj, arguments->NativeArgAt(1));
	GET_NON_NULL_NATIVE_ARGUMENT(Smi, end_obj, arguments->NativeArgAt(2));

	intptr_t start = start_obj.Value();
	intptr_t end = end_obj.Value();
	return String::SubString(receiver, start, (end - start));
	}


	DEFINE_NATIVE_ENTRY(OneByteString_substringUnchecked, 3) {
	const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
	ASSERT(receiver.IsOneByteString());
	GET_NON_NULL_NATIVE_ARGUMENT(Smi, start_obj, arguments->NativeArgAt(1));
	GET_NON_NULL_NATIVE_ARGUMENT(Smi, end_obj, arguments->NativeArgAt(2));

	const intptr_t start = start_obj.Value();
	const intptr_t end = end_obj.Value();
	return OneByteString::New(receiver, start, end - start, Heap::kNew);
	}


	// This is high-performance code.
	DEFINE_NATIVE_ENTRY(OneByteString_splitWithCharCode, 2) {
	const String& receiver = String::CheckedHandle(isolate,
	arguments->NativeArgAt(0));
	ASSERT(receiver.IsOneByteString());
	GET_NON_NULL_NATIVE_ARGUMENT(Smi, smi_split_code, arguments->NativeArgAt(1));
	const intptr_t len = receiver.Length();
	const intptr_t split_code = smi_split_code.Value();
	const GrowableObjectArray& result = GrowableObjectArray::Handle(
	isolate,
	GrowableObjectArray::New(16, Heap::kNew));
	String& str = String::Handle(isolate);
	intptr_t start = 0;
	intptr_t i = 0;
	for (; i < len; i++) {
	if (split_code == OneByteString::CharAt(receiver, i)) {
	str = OneByteString::SubStringUnchecked(receiver,
	start,
	(i - start),
	Heap::kNew);
	result.Add(str);
	start = i + 1;
	}
	}
	str = OneByteString::SubStringUnchecked(receiver,
	start,
	(i - start),
	Heap::kNew);
	result.Add(str);
	return result.raw();
	}


	DEFINE_NATIVE_ENTRY(OneByteString_allocate, 1) {
	GET_NON_NULL_NATIVE_ARGUMENT(Smi, length_obj, arguments->NativeArgAt(0));
	return OneByteString::New(length_obj.Value(), Heap::kNew);
	}


	DEFINE_NATIVE_ENTRY(OneByteString_allocateFromOneByteList, 1) {
	Instance& list = Instance::CheckedHandle(arguments->NativeArgAt(0));
	if (list.IsTypedData()) {
	const TypedData& array = TypedData::Cast(list);
	intptr_t length = array.LengthInBytes();
	return OneByteString::New(array, 0, length);
	} else if (list.IsExternalTypedData()) {
	const ExternalTypedData& array = ExternalTypedData::Cast(list);
	intptr_t length = array.LengthInBytes();
	return OneByteString::New(array, 0, length);
	} else if (RawObject::IsTypedDataViewClassId(list.GetClassId())) {
	const Instance& view = Instance::Cast(list);
	intptr_t length = Smi::Value(TypedDataView::Length(view));
	const Instance& data_obj = Instance::Handle(TypedDataView::Data(view));
	intptr_t data_offset = Smi::Value(TypedDataView::OffsetInBytes(view));
	if (data_obj.IsTypedData()) {
	const TypedData& array = TypedData::Cast(data_obj);
	return OneByteString::New(array, data_offset, length);
	} else if (data_obj.IsExternalTypedData()) {
	const ExternalTypedData& array = ExternalTypedData::Cast(data_obj);
	return OneByteString::New(array, data_offset, length);
	}
	} else if (list.IsArray()) {
	const Array& array = Array::Cast(list);
	intptr_t length = array.Length();
	String& string = String::Handle(OneByteString::New(length, Heap::kNew));
	for (int i = 0; i < length; i++) {
	intptr_t value = Smi::Value(reinterpret_cast<RawSmi*>(array.At(i)));
	OneByteString::SetCharAt(string, i, value);
	}
	return string.raw();
	} else if (list.IsGrowableObjectArray()) {
	const GrowableObjectArray& array = GrowableObjectArray::Cast(list);
	intptr_t length = array.Length();
	String& string = String::Handle(OneByteString::New(length, Heap::kNew));
	for (int i = 0; i < length; i++) {
	intptr_t value = Smi::Value(reinterpret_cast<RawSmi*>(array.At(i)));
	OneByteString::SetCharAt(string, i, value);
	}
	return string.raw();
	}
	UNREACHABLE();
	return Object::null();
	}


	DEFINE_NATIVE_ENTRY(OneByteString_setAt, 3) {
	GET_NON_NULL_NATIVE_ARGUMENT(String, receiver, arguments->NativeArgAt(0));
	ASSERT(receiver.IsOneByteString());
	GET_NON_NULL_NATIVE_ARGUMENT(Smi, index_obj, arguments->NativeArgAt(1));
	GET_NON_NULL_NATIVE_ARGUMENT(Smi, code_point_obj, arguments->NativeArgAt(2));
	ASSERT((0 <= code_point_obj.Value()) && (code_point_obj.Value() <= 0xFF));
	OneByteString::SetCharAt(receiver, index_obj.Value(), code_point_obj.Value());
	return Object::null();
	}


	DEFINE_NATIVE_ENTRY(ExternalOneByteString_getCid, 0) {
	return Smi::New(kExternalOneByteStringCid);
	}


	DEFINE_NATIVE_ENTRY(String_getHashCode, 1) {
	const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
	intptr_t hash_val = receiver.Hash();
	ASSERT(hash_val > 0);
	ASSERT(Smi::IsValid(hash_val));
	return Smi::New(hash_val);
	}


	DEFINE_NATIVE_ENTRY(String_getLength, 1) {
	const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
	return Smi::New(receiver.Length());
	}


	static int32_t StringValueAt(const String& str, const Integer& index) {
	if (index.IsSmi()) {
	const Smi& smi = Smi::Cast(index);
	intptr_t index = smi.Value();
	if ((index < 0) \|\| (index >= str.Length())) {
	const Array& args = Array::Handle(Array::New(1));
	args.SetAt(0, smi);
	Exceptions::ThrowByType(Exceptions::kRange, args);
	}
	return str.CharAt(index);
	} else {
	// An index larger than Smi is always illegal.
	const Array& args = Array::Handle(Array::New(1));
	args.SetAt(0, index);
	Exceptions::ThrowByType(Exceptions::kRange, args);
	return 0;
	}
	}


	DEFINE_NATIVE_ENTRY(String_charAt, 2) {
	const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
	GET_NON_NULL_NATIVE_ARGUMENT(Integer, index, arguments->NativeArgAt(1));
	uint32_t value = StringValueAt(receiver, index);
	ASSERT(value <= 0x10FFFF);
	return Symbols::FromCharCode(value);
	}


	DEFINE_NATIVE_ENTRY(String_codeUnitAt, 2) {
	const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
	GET_NON_NULL_NATIVE_ARGUMENT(Integer, index, arguments->NativeArgAt(1));

	int32_t value = StringValueAt(receiver, index);
	ASSERT(value >= 0);
	ASSERT(value <= 0xFFFF);
	return Smi::New(value);
	}


	DEFINE_NATIVE_ENTRY(String_concat, 2) {
	const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
	GET_NON_NULL_NATIVE_ARGUMENT(String, b, arguments->NativeArgAt(1));
	return String::Concat(receiver, b);
	}


	DEFINE_NATIVE_ENTRY(String_toLowerCase, 1) {
	const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
	ASSERT(!receiver.IsNull());
	return String::ToLowerCase(receiver);
	}


	DEFINE_NATIVE_ENTRY(String_toUpperCase, 1) {
	const String& receiver = String::CheckedHandle(arguments->NativeArgAt(0));
	ASSERT(!receiver.IsNull());
	return String::ToUpperCase(receiver);
	}


	DEFINE_NATIVE_ENTRY(String_concatRange, 3) {
	GET_NON_NULL_NATIVE_ARGUMENT(Instance, argument, arguments->NativeArgAt(0));
	GET_NON_NULL_NATIVE_ARGUMENT(Smi, start, arguments->NativeArgAt(1));
	GET_NON_NULL_NATIVE_ARGUMENT(Smi, end, arguments->NativeArgAt(2));
	const intptr_t start_ix = start.Value();
	const intptr_t end_ix = end.Value();
	if (start_ix < 0) {
	Exceptions::ThrowArgumentError(start);
	}
	Array& strings = Array::Handle();
	intptr_t length = -1;
	if (argument.IsArray()) {
	strings ^= argument.raw();
	length = strings.Length();
	} else if (argument.IsGrowableObjectArray()) {
	const GrowableObjectArray& g_array = GrowableObjectArray::Cast(argument);
	strings = g_array.data();
	length = g_array.Length();
	} else {
	Exceptions::ThrowArgumentError(argument);
	}
	if (end_ix > length) {
	Exceptions::ThrowArgumentError(end);
	}
	#if defined(DEBUG)
	// Check that the array contains strings.
	Instance& elem = Instance::Handle();
	for (intptr_t i = start_ix; i < end_ix; i++) {
	elem ^= strings.At(i);
	ASSERT(elem.IsString());
	}
	#endif
	return String::ConcatAllRange(strings, start_ix, end_ix, Heap::kNew);
	}


	DEFINE_NATIVE_ENTRY(StringBuffer_createStringFromUint16Array, 3) {
	GET_NON_NULL_NATIVE_ARGUMENT(TypedData, codeUnits, arguments->NativeArgAt(0));
	GET_NON_NULL_NATIVE_ARGUMENT(Smi, length, arguments->NativeArgAt(1));
	GET_NON_NULL_NATIVE_ARGUMENT(Bool, isLatin1, arguments->NativeArgAt(2));
	intptr_t array_length = codeUnits.Length();
	intptr_t length_value = length.Value();
	if (length_value < 0 \|\| length_value > array_length) {
	const Array& args = Array::Handle(Array::New(1));
	args.SetAt(0, length);
	Exceptions::ThrowByType(Exceptions::kRange, args);
	}
	const String& result = isLatin1.value()
	? String::Handle(OneByteString::New(length_value, Heap::kNew))
	: String::Handle(TwoByteString::New(length_value, Heap::kNew));
	NoGCScope no_gc;

	uint16_t* data_position = reinterpret_cast<uint16_t*>(codeUnits.DataAddr(0));
	String::Copy(result, 0, data_position, length_value);
	return result.raw();
	}

	} // namespace dart