[c] StringWriter.

5 files changed, 296 insertions, 58 deletions

diff --git a/GenC.fu b/GenC.fu
index 48b70ce..f00dff2 100644
--- a/GenC.fu
+++ b/GenC.fu
@@ -486,6 +486,9 @@ public class GenC : GenCCpp
 			Include("stdio.h");
 			Write("FILE *");
 			break;
+		case FuId.StringWriterClass:
+			WriteGlib("GString *");
+			break;
 		case FuId.RegexClass:
 			if (!(klass is FuReadWriteClassType))
 				Write("const ");
@@ -626,6 +629,7 @@ public class GenC : GenCCpp
 			case FuId.SortedSetClass:
 			case FuId.DictionaryClass:
 			case FuId.SortedDictionaryClass:
+			case FuId.StringWriterClass:
 			case FuId.MatchClass:
 			case FuId.LockClass:
 				return true;
@@ -732,6 +736,9 @@ public class GenC : GenCCpp
 		case FuId.SortedDictionaryClass:
 			AddListFree(FuId.SortedDictionaryClass);
 			break;
+		case FuId.StringWriterClass:
+			AddListFree(FuId.StringWriterClass);
+			break;
 		case FuId.RegexClass:
 			AddListFree(FuId.RegexClass);
 			break;
@@ -838,6 +845,9 @@ public class GenC : GenCCpp
 		case FuId.SortedDictionaryClass:
 			Write("g_tree_unref");
 			return false;
+		case FuId.StringWriterClass:
+			Write("g_string_free");
+			return false;
 		case FuId.RegexClass:
 			Write("g_regex_unref");
 			return false;
@@ -961,6 +971,9 @@ public class GenC : GenCCpp
 		case FuId.SortedDictionaryClass:
 			WriteNewTree(klass.GetKeyType(), klass.GetValueType());
 			break;
+		case FuId.StringWriterClass:
+			Write("g_string_new(NULL)");
+			break;
 		default:
 			this.SharedMake = true;
 			if (parent > FuPriority.Mul)
@@ -987,6 +1000,7 @@ public class GenC : GenCCpp
 		case FuId.SortedSetClass:
 		case FuId.DictionaryClass:
 		case FuId.SortedDictionaryClass:
+		case FuId.StringWriterClass:
 			return true;
 		default:
 			return false;
@@ -1370,6 +1384,8 @@ public class GenC : GenCCpp
 			Write(", ");
 			WriteDictionaryDestroy(klass.GetElementType());
 		}
+		else if (klass.Class.Id == FuId.StringWriterClass)
+			Write(", TRUE");
 		WriteLine(");");
 		this.Indent -= nesting;
 	}
@@ -1768,38 +1784,61 @@ public class GenC : GenCCpp
 	void WriteTextWriterWrite!(FuExpr obj, List<FuExpr#> args, bool newLine)
 	{
 		if (args.Count == 0) {
-			Write("putc('\\n', ");
-			obj.Accept(this, FuPriority.Argument);
+			if (obj.Type.AsClassType().Class.Id == FuId.StringWriterClass) {
+				Write("g_string_append_c(");
+				obj.Accept(this, FuPriority.Argument);
+				Write(", '\\n'");
+			}
+			else {
+				Write("putc('\\n', ");
+				obj.Accept(this, FuPriority.Argument);
+			}
 			WriteChar(')');
 		}
 		else if (args[0] is FuInterpolatedString interpolated) {
-			Write("fprintf(");
+			Write(obj.Type.AsClassType().Class.Id == FuId.StringWriterClass ? "g_string_append_printf(" : "fprintf(");
 			obj.Accept(this, FuPriority.Argument);
 			Write(", ");
 			WritePrintf(interpolated, newLine);
 		}
 		else if (args[0].Type is FuNumericType) {
-			Write("fprintf(");
+			Write(obj.Type.AsClassType().Class.Id == FuId.StringWriterClass ? "g_string_append_printf(" : "fprintf(");
 			obj.Accept(this, FuPriority.Argument);
 			Write(", ");
 			WritePrintfNotInterpolated(args, newLine);
 		}
 		else if (!newLine) {
-			Write("fputs(");
-			args[0].Accept(this, FuPriority.Argument);
-			Write(", ");
-			obj.Accept(this, FuPriority.Argument);
+			if (obj.Type.AsClassType().Class.Id == FuId.StringWriterClass) {
+				Write("g_string_append(");
+				obj.Accept(this, FuPriority.Argument);
+				Write(", ");
+				args[0].Accept(this, FuPriority.Argument);
+			}
+			else {
+				Write("fputs(");
+				args[0].Accept(this, FuPriority.Argument);
+				Write(", ");
+				obj.Accept(this, FuPriority.Argument);
+			}
 			WriteChar(')');
 		}
 		else if (args[0] is FuLiteralString literal) {
-			Write("fputs(");
-			WriteStringLiteralWithNewLine(literal.Value);
-			Write(", ");
-			obj.Accept(this, FuPriority.Argument);
+			if (obj.Type.AsClassType().Class.Id == FuId.StringWriterClass) {
+				Write("g_string_append(");
+				obj.Accept(this, FuPriority.Argument);
+				Write(", ");
+				WriteStringLiteralWithNewLine(literal.Value);
+			}
+			else {
+				Write("fputs(");
+				WriteStringLiteralWithNewLine(literal.Value);
+				Write(", ");
+				obj.Accept(this, FuPriority.Argument);
+			}
 			WriteChar(')');
 		}
 		else {
-			Write("fprintf(");
+			Write(obj.Type.AsClassType().Class.Id == FuId.StringWriterClass ? "g_string_append_printf(" : "fprintf(");
 			obj.Accept(this, FuPriority.Argument);
 			Write(", \"%s\\n\", ");
 			args[0].Accept(this, FuPriority.Argument);
@@ -2324,7 +2363,16 @@ public class GenC : GenCCpp
 			WriteTextWriterWrite(obj, args, false);
 			break;
 		case FuId.TextWriterWriteChar:
-			WriteCall("putc", args[0], obj);
+			if (obj.Type.AsClassType().Class.Id == FuId.StringWriterClass)
+				WriteCall("g_string_append_c", obj, args[0]);
+			else
+				WriteCall("putc", args[0], obj);
+			break;
+		case FuId.TextWriterWriteCodePoint:
+			if (obj.Type.AsClassType().Class.Id != FuId.StringWriterClass)
+				NotSupported(obj, method.Name);
+			else
+				WriteCall("g_string_append_unichar", obj, args[0]);
 			break;
 		case FuId.TextWriterWriteLine:
 			WriteTextWriterWrite(obj, args, true);
@@ -2335,6 +2383,14 @@ public class GenC : GenCCpp
 		case FuId.ConsoleWriteLine:
 			WriteConsoleWrite(args, true);
 			break;
+		case FuId.StringWriterClear:
+			Write("g_string_truncate(");
+			obj.Accept(this, FuPriority.Argument);
+			Write(", 0)");
+			break;
+		case FuId.StringWriterToString:
+			WritePostfix(obj, "->str");
+			break;
 		case FuId.ConvertToBase64String:
 			WriteGlib("g_base64_encode(");
 			WriteArrayPtrAdd(args[0], args[1]);
@@ -2676,6 +2732,8 @@ public class GenC : GenCCpp
 			WriteDestructMethodName(owning);
 			WriteChar('(');
 			statement.Accept(this, FuPriority.Argument);
+			if (owning.Class.Id == FuId.StringWriterClass)
+				Write(", TRUE");
 			WriteLine(");");
 			CleanupTemporaries();
 		}
diff --git a/libfut.cpp b/libfut.cpp
index 099f962..6a1756c 100644
--- a/libfut.cpp
+++ b/libfut.cpp
@@ -9388,6 +9388,9 @@ void GenC::writeClassType(const FuClassType * klass, bool space)
 		include("stdio.h");
 		write("FILE *");
 		break;
+	case FuId::stringWriterClass:
+		writeGlib("GString *");
+		break;
 	case FuId::regexClass:
 		if (!dynamic_cast<const FuReadWriteClassType *>(klass))
 			write("const ");
@@ -9531,6 +9534,7 @@ bool GenC::needToDestructType(const FuType * type)
 		case FuId::sortedSetClass:
 		case FuId::dictionaryClass:
 		case FuId::sortedDictionaryClass:
+		case FuId::stringWriterClass:
 		case FuId::matchClass:
 		case FuId::lockClass:
 			return true;
@@ -9639,6 +9643,9 @@ void GenC::writeListFree(const FuClassType * elementType)
 	case FuId::sortedDictionaryClass:
 		addListFree(FuId::sortedDictionaryClass);
 		break;
+	case FuId::stringWriterClass:
+		addListFree(FuId::stringWriterClass);
+		break;
 	case FuId::regexClass:
 		addListFree(FuId::regexClass);
 		break;
@@ -9743,6 +9750,9 @@ bool GenC::writeDestructMethodName(const FuClassType * klass)
 	case FuId::sortedDictionaryClass:
 		write("g_tree_unref");
 		return false;
+	case FuId::stringWriterClass:
+		write("g_string_free");
+		return false;
 	case FuId::regexClass:
 		write("g_regex_unref");
 		return false;
@@ -9862,6 +9872,9 @@ void GenC::writeNew(const FuReadWriteClassType * klass, FuPriority parent)
 	case FuId::sortedDictionaryClass:
 		writeNewTree(klass->getKeyType(), klass->getValueType().get());
 		break;
+	case FuId::stringWriterClass:
+		write("g_string_new(NULL)");
+		break;
 	default:
 		this->sharedMake = true;
 		if (parent > FuPriority::mul)
@@ -9888,6 +9901,7 @@ bool GenC::isCollection(const FuClass * klass)
 	case FuId::sortedSetClass:
 	case FuId::dictionaryClass:
 	case FuId::sortedDictionaryClass:
+	case FuId::stringWriterClass:
 		return true;
 	default:
 		return false;
@@ -10252,6 +10266,8 @@ void GenC::writeDestruct(const FuSymbol * symbol)
 		write(", ");
 		writeDictionaryDestroy(klass->getElementType().get());
 	}
+	else if (klass->class_->id == FuId::stringWriterClass)
+		write(", TRUE");
 	writeLine(");");
 	this->indent -= nesting;
 }
@@ -10652,38 +10668,61 @@ void GenC::writePrintfNotInterpolated(const std::vector<std::shared_ptr<FuExpr>>
 void GenC::writeTextWriterWrite(const FuExpr * obj, const std::vector<std::shared_ptr<FuExpr>> * args, bool newLine)
 {
 	if (std::ssize(*args) == 0) {
-		write("putc('\\n', ");
-		obj->accept(this, FuPriority::argument);
+		if (obj->type->asClassType()->class_->id == FuId::stringWriterClass) {
+			write("g_string_append_c(");
+			obj->accept(this, FuPriority::argument);
+			write(", '\\n'");
+		}
+		else {
+			write("putc('\\n', ");
+			obj->accept(this, FuPriority::argument);
+		}
 		writeChar(')');
 	}
 	else if (const FuInterpolatedString *interpolated = dynamic_cast<const FuInterpolatedString *>((*args)[0].get())) {
-		write("fprintf(");
+		write(obj->type->asClassType()->class_->id == FuId::stringWriterClass ? "g_string_append_printf(" : "fprintf(");
 		obj->accept(this, FuPriority::argument);
 		write(", ");
 		writePrintf(interpolated, newLine);
 	}
 	else if (dynamic_cast<const FuNumericType *>((*args)[0]->type.get())) {
-		write("fprintf(");
+		write(obj->type->asClassType()->class_->id == FuId::stringWriterClass ? "g_string_append_printf(" : "fprintf(");
 		obj->accept(this, FuPriority::argument);
 		write(", ");
 		writePrintfNotInterpolated(args, newLine);
 	}
 	else if (!newLine) {
-		write("fputs(");
-		(*args)[0]->accept(this, FuPriority::argument);
-		write(", ");
-		obj->accept(this, FuPriority::argument);
+		if (obj->type->asClassType()->class_->id == FuId::stringWriterClass) {
+			write("g_string_append(");
+			obj->accept(this, FuPriority::argument);
+			write(", ");
+			(*args)[0]->accept(this, FuPriority::argument);
+		}
+		else {
+			write("fputs(");
+			(*args)[0]->accept(this, FuPriority::argument);
+			write(", ");
+			obj->accept(this, FuPriority::argument);
+		}
 		writeChar(')');
 	}
 	else if (const FuLiteralString *literal = dynamic_cast<const FuLiteralString *>((*args)[0].get())) {
-		write("fputs(");
-		writeStringLiteralWithNewLine(literal->value);
-		write(", ");
-		obj->accept(this, FuPriority::argument);
+		if (obj->type->asClassType()->class_->id == FuId::stringWriterClass) {
+			write("g_string_append(");
+			obj->accept(this, FuPriority::argument);
+			write(", ");
+			writeStringLiteralWithNewLine(literal->value);
+		}
+		else {
+			write("fputs(");
+			writeStringLiteralWithNewLine(literal->value);
+			write(", ");
+			obj->accept(this, FuPriority::argument);
+		}
 		writeChar(')');
 	}
 	else {
-		write("fprintf(");
+		write(obj->type->asClassType()->class_->id == FuId::stringWriterClass ? "g_string_append_printf(" : "fprintf(");
 		obj->accept(this, FuPriority::argument);
 		write(", \"%s\\n\", ");
 		(*args)[0]->accept(this, FuPriority::argument);
@@ -11227,7 +11266,16 @@ void GenC::writeCallExpr(const FuExpr * obj, const FuMethod * method, const std:
 		writeTextWriterWrite(obj, args, false);
 		break;
 	case FuId::textWriterWriteChar:
-		writeCall("putc", (*args)[0].get(), obj);
+		if (obj->type->asClassType()->class_->id == FuId::stringWriterClass)
+			writeCall("g_string_append_c", obj, (*args)[0].get());
+		else
+			writeCall("putc", (*args)[0].get(), obj);
+		break;
+	case FuId::textWriterWriteCodePoint:
+		if (obj->type->asClassType()->class_->id != FuId::stringWriterClass)
+			notSupported(obj, method->name);
+		else
+			writeCall("g_string_append_unichar", obj, (*args)[0].get());
 		break;
 	case FuId::textWriterWriteLine:
 		writeTextWriterWrite(obj, args, true);
@@ -11238,6 +11286,14 @@ void GenC::writeCallExpr(const FuExpr * obj, const FuMethod * method, const std:
 	case FuId::consoleWriteLine:
 		writeConsoleWrite(args, true);
 		break;
+	case FuId::stringWriterClear:
+		write("g_string_truncate(");
+		obj->accept(this, FuPriority::argument);
+		write(", 0)");
+		break;
+	case FuId::stringWriterToString:
+		writePostfix(obj, "->str");
+		break;
 	case FuId::convertToBase64String:
 		writeGlib("g_base64_encode(");
 		writeArrayPtrAdd((*args)[0].get(), (*args)[1].get());
@@ -11584,6 +11640,8 @@ void GenC::visitExpr(const FuExpr * statement)
 			writeDestructMethodName(owning);
 			writeChar('(');
 			statement->accept(this, FuPriority::argument);
+			if (owning->class_->id == FuId::stringWriterClass)
+				write(", TRUE");
 			writeLine(");");
 			cleanupTemporaries();
 		}
diff --git a/libfut.cs b/libfut.cs
index 858c6d2..762deab 100644
--- a/libfut.cs
+++ b/libfut.cs
@@ -9689,6 +9689,9 @@ namespace Fusion
 				Include("stdio.h");
 				Write("FILE *");
 				break;
+			case FuId.StringWriterClass:
+				WriteGlib("GString *");
+				break;
 			case FuId.RegexClass:
 				if (!(klass is FuReadWriteClassType))
 					Write("const ");
@@ -9829,6 +9832,7 @@ namespace Fusion
 				case FuId.SortedSetClass:
 				case FuId.DictionaryClass:
 				case FuId.SortedDictionaryClass:
+				case FuId.StringWriterClass:
 				case FuId.MatchClass:
 				case FuId.LockClass:
 					return true;
@@ -9935,6 +9939,9 @@ namespace Fusion
 			case FuId.SortedDictionaryClass:
 				AddListFree(FuId.SortedDictionaryClass);
 				break;
+			case FuId.StringWriterClass:
+				AddListFree(FuId.StringWriterClass);
+				break;
 			case FuId.RegexClass:
 				AddListFree(FuId.RegexClass);
 				break;
@@ -10041,6 +10048,9 @@ namespace Fusion
 			case FuId.SortedDictionaryClass:
 				Write("g_tree_unref");
 				return false;
+			case FuId.StringWriterClass:
+				Write("g_string_free");
+				return false;
 			case FuId.RegexClass:
 				Write("g_regex_unref");
 				return false;
@@ -10164,6 +10174,9 @@ namespace Fusion
 			case FuId.SortedDictionaryClass:
 				WriteNewTree(klass.GetKeyType(), klass.GetValueType());
 				break;
+			case FuId.StringWriterClass:
+				Write("g_string_new(NULL)");
+				break;
 			default:
 				this.SharedMake = true;
 				if (parent > FuPriority.Mul)
@@ -10190,6 +10203,7 @@ namespace Fusion
 			case FuId.SortedSetClass:
 			case FuId.DictionaryClass:
 			case FuId.SortedDictionaryClass:
+			case FuId.StringWriterClass:
 				return true;
 			default:
 				return false;
@@ -10558,6 +10572,8 @@ namespace Fusion
 				Write(", ");
 				WriteDictionaryDestroy(klass.GetElementType());
 			}
+			else if (klass.Class.Id == FuId.StringWriterClass)
+				Write(", TRUE");
 			WriteLine(");");
 			this.Indent -= nesting;
 		}
@@ -10955,38 +10971,61 @@ namespace Fusion
 		void WriteTextWriterWrite(FuExpr obj, List<FuExpr> args, bool newLine)
 		{
 			if (args.Count == 0) {
-				Write("putc('\\n', ");
-				obj.Accept(this, FuPriority.Argument);
+				if (obj.Type.AsClassType().Class.Id == FuId.StringWriterClass) {
+					Write("g_string_append_c(");
+					obj.Accept(this, FuPriority.Argument);
+					Write(", '\\n'");
+				}
+				else {
+					Write("putc('\\n', ");
+					obj.Accept(this, FuPriority.Argument);
+				}
 				WriteChar(')');
 			}
 			else if (args[0] is FuInterpolatedString interpolated) {
-				Write("fprintf(");
+				Write(obj.Type.AsClassType().Class.Id == FuId.StringWriterClass ? "g_string_append_printf(" : "fprintf(");
 				obj.Accept(this, FuPriority.Argument);
 				Write(", ");
 				WritePrintf(interpolated, newLine);
 			}
 			else if (args[0].Type is FuNumericType) {
-				Write("fprintf(");
+				Write(obj.Type.AsClassType().Class.Id == FuId.StringWriterClass ? "g_string_append_printf(" : "fprintf(");
 				obj.Accept(this, FuPriority.Argument);
 				Write(", ");
 				WritePrintfNotInterpolated(args, newLine);
 			}
 			else if (!newLine) {
-				Write("fputs(");
-				args[0].Accept(this, FuPriority.Argument);
-				Write(", ");
-				obj.Accept(this, FuPriority.Argument);
+				if (obj.Type.AsClassType().Class.Id == FuId.StringWriterClass) {
+					Write("g_string_append(");
+					obj.Accept(this, FuPriority.Argument);
+					Write(", ");
+					args[0].Accept(this, FuPriority.Argument);
+				}
+				else {
+					Write("fputs(");
+					args[0].Accept(this, FuPriority.Argument);
+					Write(", ");
+					obj.Accept(this, FuPriority.Argument);
+				}
 				WriteChar(')');
 			}
 			else if (args[0] is FuLiteralString literal) {
-				Write("fputs(");
-				WriteStringLiteralWithNewLine(literal.Value);
-				Write(", ");
-				obj.Accept(this, FuPriority.Argument);
+				if (obj.Type.AsClassType().Class.Id == FuId.StringWriterClass) {
+					Write("g_string_append(");
+					obj.Accept(this, FuPriority.Argument);
+					Write(", ");
+					WriteStringLiteralWithNewLine(literal.Value);
+				}
+				else {
+					Write("fputs(");
+					WriteStringLiteralWithNewLine(literal.Value);
+					Write(", ");
+					obj.Accept(this, FuPriority.Argument);
+				}
 				WriteChar(')');
 			}
 			else {
-				Write("fprintf(");
+				Write(obj.Type.AsClassType().Class.Id == FuId.StringWriterClass ? "g_string_append_printf(" : "fprintf(");
 				obj.Accept(this, FuPriority.Argument);
 				Write(", \"%s\\n\", ");
 				args[0].Accept(this, FuPriority.Argument);
@@ -11507,7 +11546,16 @@ namespace Fusion
 				WriteTextWriterWrite(obj, args, false);
 				break;
 			case FuId.TextWriterWriteChar:
-				WriteCall("putc", args[0], obj);
+				if (obj.Type.AsClassType().Class.Id == FuId.StringWriterClass)
+					WriteCall("g_string_append_c", obj, args[0]);
+				else
+					WriteCall("putc", args[0], obj);
+				break;
+			case FuId.TextWriterWriteCodePoint:
+				if (obj.Type.AsClassType().Class.Id != FuId.StringWriterClass)
+					NotSupported(obj, method.Name);
+				else
+					WriteCall("g_string_append_unichar", obj, args[0]);
 				break;
 			case FuId.TextWriterWriteLine:
 				WriteTextWriterWrite(obj, args, true);
@@ -11518,6 +11566,14 @@ namespace Fusion
 			case FuId.ConsoleWriteLine:
 				WriteConsoleWrite(args, true);
 				break;
+			case FuId.StringWriterClear:
+				Write("g_string_truncate(");
+				obj.Accept(this, FuPriority.Argument);
+				Write(", 0)");
+				break;
+			case FuId.StringWriterToString:
+				WritePostfix(obj, "->str");
+				break;
 			case FuId.ConvertToBase64String:
 				WriteGlib("g_base64_encode(");
 				WriteArrayPtrAdd(args[0], args[1]);
@@ -11859,6 +11915,8 @@ namespace Fusion
 				WriteDestructMethodName(owning);
 				WriteChar('(');
 				statement.Accept(this, FuPriority.Argument);
+				if (owning.Class.Id == FuId.StringWriterClass)
+					Write(", TRUE");
 				WriteLine(");");
 				CleanupTemporaries();
 			}
diff --git a/libfut.js b/libfut.js
index d7e2ab9..6bb23b1 100644
--- a/libfut.js
+++ b/libfut.js
@@ -10023,6 +10023,9 @@ export class GenC extends GenCCpp
 			this.include("stdio.h");
 			this.write("FILE *");
 			break;
+		case FuId.STRING_WRITER_CLASS:
+			this.#writeGlib("GString *");
+			break;
 		case FuId.REGEX_CLASS:
 			if (!(klass instanceof FuReadWriteClassType))
 				this.write("const ");
@@ -10170,6 +10173,7 @@ export class GenC extends GenCCpp
 			case FuId.SORTED_SET_CLASS:
 			case FuId.DICTIONARY_CLASS:
 			case FuId.SORTED_DICTIONARY_CLASS:
+			case FuId.STRING_WRITER_CLASS:
 			case FuId.MATCH_CLASS:
 			case FuId.LOCK_CLASS:
 				return true;
@@ -10279,6 +10283,9 @@ export class GenC extends GenCCpp
 		case FuId.SORTED_DICTIONARY_CLASS:
 			this.#addListFree(FuId.SORTED_DICTIONARY_CLASS);
 			break;
+		case FuId.STRING_WRITER_CLASS:
+			this.#addListFree(FuId.STRING_WRITER_CLASS);
+			break;
 		case FuId.REGEX_CLASS:
 			this.#addListFree(FuId.REGEX_CLASS);
 			break;
@@ -10386,6 +10393,9 @@ export class GenC extends GenCCpp
 		case FuId.SORTED_DICTIONARY_CLASS:
 			this.write("g_tree_unref");
 			return false;
+		case FuId.STRING_WRITER_CLASS:
+			this.write("g_string_free");
+			return false;
 		case FuId.REGEX_CLASS:
 			this.write("g_regex_unref");
 			return false;
@@ -10506,6 +10516,9 @@ export class GenC extends GenCCpp
 		case FuId.SORTED_DICTIONARY_CLASS:
 			this.#writeNewTree(klass.getKeyType(), klass.getValueType());
 			break;
+		case FuId.STRING_WRITER_CLASS:
+			this.write("g_string_new(NULL)");
+			break;
 		default:
 			this.#sharedMake = true;
 			if (parent > FuPriority.MUL)
@@ -10532,6 +10545,7 @@ export class GenC extends GenCCpp
 		case FuId.SORTED_SET_CLASS:
 		case FuId.DICTIONARY_CLASS:
 		case FuId.SORTED_DICTIONARY_CLASS:
+		case FuId.STRING_WRITER_CLASS:
 			return true;
 		default:
 			return false;
@@ -10926,6 +10940,8 @@ export class GenC extends GenCCpp
 			this.write(", ");
 			this.#writeDictionaryDestroy(klass.getElementType());
 		}
+		else if (klass.class.id == FuId.STRING_WRITER_CLASS)
+			this.write(", TRUE");
 		this.writeLine(");");
 		this.indent -= nesting;
 	}
@@ -11331,42 +11347,65 @@ export class GenC extends GenCCpp
 	#writeTextWriterWrite(obj, args, newLine)
 	{
 		if (args.length == 0) {
-			this.write("putc('\\n', ");
-			obj.accept(this, FuPriority.ARGUMENT);
+			if (obj.type.asClassType().class.id == FuId.STRING_WRITER_CLASS) {
+				this.write("g_string_append_c(");
+				obj.accept(this, FuPriority.ARGUMENT);
+				this.write(", '\\n'");
+			}
+			else {
+				this.write("putc('\\n', ");
+				obj.accept(this, FuPriority.ARGUMENT);
+			}
 			this.writeChar(41);
 		}
 		else {
 			let interpolated;
 			if ((interpolated = args[0]) instanceof FuInterpolatedString) {
-				this.write("fprintf(");
+				this.write(obj.type.asClassType().class.id == FuId.STRING_WRITER_CLASS ? "g_string_append_printf(" : "fprintf(");
 				obj.accept(this, FuPriority.ARGUMENT);
 				this.write(", ");
 				this.writePrintf(interpolated, newLine);
 			}
 			else if (args[0].type instanceof FuNumericType) {
-				this.write("fprintf(");
+				this.write(obj.type.asClassType().class.id == FuId.STRING_WRITER_CLASS ? "g_string_append_printf(" : "fprintf(");
 				obj.accept(this, FuPriority.ARGUMENT);
 				this.write(", ");
 				this.writePrintfNotInterpolated(args, newLine);
 			}
 			else if (!newLine) {
-				this.write("fputs(");
-				args[0].accept(this, FuPriority.ARGUMENT);
-				this.write(", ");
-				obj.accept(this, FuPriority.ARGUMENT);
+				if (obj.type.asClassType().class.id == FuId.STRING_WRITER_CLASS) {
+					this.write("g_string_append(");
+					obj.accept(this, FuPriority.ARGUMENT);
+					this.write(", ");
+					args[0].accept(this, FuPriority.ARGUMENT);
+				}
+				else {
+					this.write("fputs(");
+					args[0].accept(this, FuPriority.ARGUMENT);
+					this.write(", ");
+					obj.accept(this, FuPriority.ARGUMENT);
+				}
 				this.writeChar(41);
 			}
 			else {
 				let literal;
 				if ((literal = args[0]) instanceof FuLiteralString) {
-					this.write("fputs(");
-					this.writeStringLiteralWithNewLine(literal.value);
-					this.write(", ");
-					obj.accept(this, FuPriority.ARGUMENT);
+					if (obj.type.asClassType().class.id == FuId.STRING_WRITER_CLASS) {
+						this.write("g_string_append(");
+						obj.accept(this, FuPriority.ARGUMENT);
+						this.write(", ");
+						this.writeStringLiteralWithNewLine(literal.value);
+					}
+					else {
+						this.write("fputs(");
+						this.writeStringLiteralWithNewLine(literal.value);
+						this.write(", ");
+						obj.accept(this, FuPriority.ARGUMENT);
+					}
 					this.writeChar(41);
 				}
 				else {
-					this.write("fprintf(");
+					this.write(obj.type.asClassType().class.id == FuId.STRING_WRITER_CLASS ? "g_string_append_printf(" : "fprintf(");
 					obj.accept(this, FuPriority.ARGUMENT);
 					this.write(", \"%s\\n\", ");
 					args[0].accept(this, FuPriority.ARGUMENT);
@@ -11895,7 +11934,16 @@ export class GenC extends GenCCpp
 			this.#writeTextWriterWrite(obj, args, false);
 			break;
 		case FuId.TEXT_WRITER_WRITE_CHAR:
-			this.writeCall("putc", args[0], obj);
+			if (obj.type.asClassType().class.id == FuId.STRING_WRITER_CLASS)
+				this.writeCall("g_string_append_c", obj, args[0]);
+			else
+				this.writeCall("putc", args[0], obj);
+			break;
+		case FuId.TEXT_WRITER_WRITE_CODE_POINT:
+			if (obj.type.asClassType().class.id != FuId.STRING_WRITER_CLASS)
+				this.notSupported(obj, method.name);
+			else
+				this.writeCall("g_string_append_unichar", obj, args[0]);
 			break;
 		case FuId.TEXT_WRITER_WRITE_LINE:
 			this.#writeTextWriterWrite(obj, args, true);
@@ -11906,6 +11954,14 @@ export class GenC extends GenCCpp
 		case FuId.CONSOLE_WRITE_LINE:
 			this.#writeConsoleWrite(args, true);
 			break;
+		case FuId.STRING_WRITER_CLEAR:
+			this.write("g_string_truncate(");
+			obj.accept(this, FuPriority.ARGUMENT);
+			this.write(", 0)");
+			break;
+		case FuId.STRING_WRITER_TO_STRING:
+			this.writePostfix(obj, "->str");
+			break;
 		case FuId.CONVERT_TO_BASE64_STRING:
 			this.#writeGlib("g_base64_encode(");
 			this.writeArrayPtrAdd(args[0], args[1]);
@@ -12252,6 +12308,8 @@ export class GenC extends GenCCpp
 				this.#writeDestructMethodName(owning);
 				this.writeChar(40);
 				statement.accept(this, FuPriority.ARGUMENT);
+				if (owning.class.id == FuId.STRING_WRITER_CLASS)
+					this.write(", TRUE");
 				this.writeLine(");");
 				this.cleanupTemporaries();
 			}
diff --git a/test/StringWriter.fu b/test/StringWriter.fu
index 3cc2872..8fc4b8e 100644
--- a/test/StringWriter.fu
+++ b/test/StringWriter.fu
@@ -2,17 +2,23 @@ public static class Test
 {
 	public static bool Run()
 	{
-		StringWriter() w; //FAIL: c d swift TODO; cl
+		StringWriter() w; //FAIL: d swift TODO; cl
 		w.Write("kill me");
 		w.Clear();
 		w.Write("Hello");
 		string s = "World";
 		w.Write(s);
+		long l = 5;
+#if C
+		w.Write(42);
+		w.Write(l);
+		w.Write('c');
+#else
 		TextWriter! tw = w; //FAIL: ts
 		tw.Write(42);
-		long l = 5;
 		w.Write(l);
 		tw.Write('c');
+#endif
 		w.WriteChar('c');
 		return w.ToString() == "HelloWorld42599c";
 	}