Provide a code point iterator to the String class to simplify iteration.

runtime/vm/object_test.cc

 // 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.
 
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/bigint_operations.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
@@ skipping 1534 matching lines @@
 
   other_array = Array::New(kArrayLen - 1);
   other_array.SetAt(0, array);
   other_array.SetAt(2, array);
   EXPECT(!array.Equals(other_array));
 
   EXPECT_EQ(0, Array::Handle(Object::empty_array()).Length());
 }
 
 
+TEST_CASE(StringCodePointIterator) {
+  const String& str0 = String::Handle(String::New(""));
+  String::CodePointIterator it0(str0);
+  EXPECT(!it0.Next());
+
+  const String& str1 = String::Handle(String::New(" \xc3\xa7 "));
+  String::CodePointIterator it1(str1);
+  EXPECT(it1.Next());
+  EXPECT_EQ(' ', it1.Current());
+  EXPECT(it1.Next());
+  EXPECT_EQ(0xE7, it1.Current());
+  EXPECT(it1.Next());
+  EXPECT_EQ(' ', it1.Current());
+  EXPECT(!it1.Next());
+
+  const String& str2 = String::Handle(String::New("\xD7\x92\xD7\x9C"
+                                                  "\xD7\xA2\xD7\x93"
+                                                  "\xD7\x91\xD7\xA8"
+                                                  "\xD7\x9B\xD7\x94"));
+  String::CodePointIterator it2(str2);
+  EXPECT(it2.Next());
+  EXPECT_EQ(0x5D2, it2.Current());
+  EXPECT(it2.Next());
+  EXPECT_EQ(0x5DC, it2.Current());
+  EXPECT(it2.Next());
+  EXPECT_EQ(0x5E2, it2.Current());
+  EXPECT(it2.Next());
+  EXPECT_EQ(0x5D3, it2.Current());
+  EXPECT(it2.Next());
+  EXPECT_EQ(0x5D1, it2.Current());
+  EXPECT(it2.Next());
+  EXPECT_EQ(0x5E8, it2.Current());
+  EXPECT(it2.Next());
+  EXPECT_EQ(0x5DB, it2.Current());
+  EXPECT(it2.Next());
+  EXPECT_EQ(0x5D4, it2.Current());
+  EXPECT(!it2.Next());
+
+  const String& str3 = String::Handle(String::New("\xF0\x9D\x91\xA0"
+                                                  "\xF0\x9D\x91\xA1"
+                                                  "\xF0\x9D\x91\xA2"
+                                                  "\xF0\x9D\x91\xA3"));
+  String::CodePointIterator it3(str3);
+  EXPECT(it3.Next());
+  EXPECT_EQ(0x1D460, it3.Current());
+  EXPECT(it3.Next());
+  EXPECT_EQ(0x1D461, it3.Current());
+  EXPECT(it3.Next());
+  EXPECT_EQ(0x1D462, it3.Current());
+  EXPECT(it3.Next());
+  EXPECT_EQ(0x1D463, it3.Current());
+  EXPECT(!it3.Next());
+}
+
+
 TEST_CASE(GrowableObjectArray) {
   const int kArrayLen = 5;
   Smi& value = Smi::Handle();
   Smi& expected_value = Smi::Handle();
   GrowableObjectArray& array = GrowableObjectArray::Handle();
 
   // Test basic growing functionality.
   array = GrowableObjectArray::New(kArrayLen);
   EXPECT_EQ(kArrayLen, array.Capacity());
   EXPECT_EQ(0, array.Length());
@@ skipping 1466 matching lines @@
   isolate->heap()->CollectAllGarbage();
   EXPECT(weak1.key() == Object::null());
   EXPECT(weak1.value() == Object::null());
   EXPECT(weak2.key() == Object::null());
   EXPECT(weak2.value() == Object::null());
 }
 
 #endif  // defined(TARGET_ARCH_IA32) || defined(TARGET_ARCH_X64).
 
 }  // namespace dart