Added transcoding support in Writer and PrettyWriter

git-svn-id: https://rapidjson.googlecode.com/svn/trunk@47 c5894555-1306-4e8d-425f-1f6f381ee07c

include/rapidjson/prettywriter.h

@@ -11,10 +11,10 @@ namespace rapidjson {
 	\tparam Encoding Encoding of both source strings and output.
 	\tparam Allocator Type of allocator for allocating memory of stack.
 */
-template<typename Stream, typename Encoding = UTF8<>, typename Allocator = MemoryPoolAllocator<> >
-class PrettyWriter : public Writer<Stream, Encoding, Allocator> {
+template<typename Stream, typename SourceEncoding = UTF8<>, typename TargetEncoding = UTF8<>, typename Allocator = MemoryPoolAllocator<> >
+class PrettyWriter : public Writer<Stream, SourceEncoding, TargetEncoding, Allocator> {
 public:
-	typedef Writer<Stream, Encoding, Allocator> Base;
+	typedef Writer<Stream, SourceEncoding, TargetEncoding, Allocator> Base;
 	typedef typename Base::Ch Ch;
 
 	//! Constructor

include/rapidjson/writer.h

@@ -23,10 +23,10 @@ namespace rapidjson {
 	\tparam Encoding Encoding of both source strings and output.
 	\implements Handler
 */
-template<typename Stream, typename Encoding = UTF8<>, typename Allocator = MemoryPoolAllocator<> >
+template<typename Stream, typename SourceEncoding = UTF8<>, typename TargetEncoding = UTF8<>, typename Allocator = MemoryPoolAllocator<> >
 class Writer {
 public:
-	typedef typename Encoding::Ch Ch;
+	typedef typename SourceEncoding::Ch Ch;
 
 	Writer(Stream& stream, Allocator* allocator = 0, size_t levelDepth = kDefaultLevelDepth) : 
 		stream_(stream), level_stack_(allocator, levelDepth * sizeof(Level)) {}
@@ -166,7 +166,7 @@ protected:
 	}
 
 	void WriteString(const Ch* str, SizeType length)  {
-		static const char hexDigits[] = "0123456789ABCDEF";
+		static const char hexDigits[16] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
 		static const char escape[256] = {
 #define Z16 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
 			//0    1    2    3    4    5    6    7    8    9    A    B    C    D    E    F
@@ -180,19 +180,22 @@ protected:
 		};
 
 		stream_.Put('\"');
-		for (const Ch* p = str; p != str + length; ++p) {
-			if ((sizeof(Ch) == 1 || *p < 256) && escape[(unsigned char)*p])  {
+		GenericStringStream<SourceEncoding> is(str);
+		while (is.Tell() < length) {
+			const Ch c = is.Peek();
+			if ((sizeof(Ch) == 1 || (unsigned)c < 256) && escape[(unsigned char)c])  {
+				is.Take();
 				stream_.Put('\\');
-				stream_.Put(escape[(unsigned char)*p]);
-				if (escape[(unsigned char)*p] == 'u') {
+				stream_.Put(escape[(unsigned char)c]);
+				if (escape[(unsigned char)c] == 'u') {
 					stream_.Put('0');
 					stream_.Put('0');
-					stream_.Put(hexDigits[(*p) >> 4]);
-					stream_.Put(hexDigits[(*p) & 0xF]);
+					stream_.Put(hexDigits[(unsigned char)c >> 4]);
+					stream_.Put(hexDigits[(unsigned char)c & 0xF]);
 				}
 			}
 			else
-				stream_.Put(*p);
+				Transcoder<SourceEncoding, TargetEncoding>::Transcode(is, stream_);
 		}
 		stream_.Put('\"');
 	}

test/unittest/writertest.cpp

@@ -54,3 +54,13 @@ TEST(Writer, String) {
 	TEST_ROUNDTRIP("[\"Hello\\u0000World\"]");
 	TEST_ROUNDTRIP("[\"\\\"\\\\/\\b\\f\\n\\r\\t\"]");
 }
+
+TEST(Writer, Transcode) {
+	// UTF8 -> UTF16 -> UTF8
+	StringStream s("{ \"hello\" : \"world\", \"t\" : true , \"f\" : false, \"n\": null, \"i\":123, \"pi\": 3.1416, \"a\":[1, 2, 3], \"dollar\":\"\x24\", \"cents\":\"\xC2\xA2\", \"euro\":\"\xE2\x82\xAC\", \"gclef\":\"\xF0\x9D\x84\x9E\" } ");
+	StringBuffer buffer;
+	Writer<StringBuffer, UTF16<>, UTF8<> > writer(buffer);
+	GenericReader<UTF8<>, UTF16<> > reader;
+	reader.Parse<0>(s, writer);
+	EXPECT_STREQ("{\"hello\":\"world\",\"t\":true,\"f\":false,\"n\":null,\"i\":123,\"pi\":3.1416,\"a\":[1,2,3],\"dollar\":\"\x24\",\"cents\":\"\xC2\xA2\",\"euro\":\"\xE2\x82\xAC\",\"gclef\":\"\xF0\x9D\x84\x9E\"}", buffer.GetString());
+}
\ No newline at end of file