[error] Restrict use of "this".

AST.fu

@@ -336,12 +336,6 @@ public class FuScope : FuSymbol
 
 	public int Count() => this.Dict.Count;
 
-	public FuVar!? FirstParameter()
-	{
-		assert this.First is FuVar! result; // FIXME: FuVar!?
-		return result;
-	}
-
 	public FuContainerType! GetContainer!()
 	{
 		for (FuScope!? scope = this; scope != null; scope = scope.Parent) {
@@ -827,8 +821,12 @@ class FuForeach : FuLoop
 {
 	internal FuExpr# Collection;
 	public override void AcceptStatement(FuVisitor! visitor) { visitor.VisitForeach(this); }
-	public FuVar! GetVar() => this.FirstParameter();
-	public FuVar! GetValueVar() => this.FirstParameter().NextParameter();
+	public FuVar! GetVar()
+	{
+		assert this.First is FuVar! result;
+		return result;
+	}
+	public FuVar! GetValueVar() => this.GetVar().NextVar();
 }
 
 class FuIf : FuCondCompletionStatement
@@ -1057,9 +1055,9 @@ public class FuVar : FuNamedValue
 	public static FuVar# New(FuType#? type, string name, FuExpr#? defaultValue = null)
 		=> new FuVar { Type = type, Name = name, Value = defaultValue };
 	public override void Accept(FuVisitor! visitor, FuPriority parent) { visitor.VisitVar(this); }
-	public FuVar!? NextParameter()
+	public FuVar!? NextVar()
 	{
-		assert this.Next is FuVar! def;
+		assert this.Next is FuVar! def; // FIXME: FuVar!?
 		return def;
 	}
 }
@@ -1100,23 +1098,30 @@ class FuStaticProperty : FuMember
 
 public class FuMethodBase : FuMember
 {
-	internal bool IsMutator = false;
+	internal FuParameters() Parameters;
 	internal bool Throws;
 	internal FuStatement#? Body;
 	internal bool IsLive = false;
 	internal HashSet<FuMethod!>() Calls;
 	public override bool IsStatic() => false; // constructor
+	public void AddThis!(FuClass? klass, bool isMutator)
+	{
+		FuClassType# type = isMutator ? new FuReadWriteClassType() : new FuClassType();
+		type.Class = klass;
+		this.Parameters.Add(FuVar.New(type, "this"));
+	}
+	public bool IsMutator() => this.Parameters.First.Type is FuReadWriteClassType;
 }
 
 public class FuMethod : FuMethodBase
 {
 	internal FuCallType CallType;
-	internal FuParameters() Parameters;
 	internal FuScope() MethodScope;
-	public static FuMethod# New(FuClass!? klass, FuVisibility visibility, FuCallType callType, FuType# type, FuId id, string name, bool isMutator, FuVar#? param0 = null, FuVar#? param1 = null, FuVar#? param2 = null, FuVar#? param3 = null)
+	public static FuMethod# New(FuClass? klass, FuVisibility visibility, FuCallType callType, FuType# type, FuId id, string name, bool isMutator, FuVar#? param0 = null, FuVar#? param1 = null, FuVar#? param2 = null, FuVar#? param3 = null)
 	{
 		FuMethod# result = new FuMethod { Visibility = visibility, CallType = callType, Type = type, Id = id, Name = name };
-		result.IsMutator = isMutator;
+		if (callType != FuCallType.Static)
+			result.AddThis(klass, isMutator);
 		if (param0 != null) {
 			result.Parameters.Add(param0);
 			if (param1 != null) {
@@ -1132,6 +1137,16 @@ public class FuMethod : FuMethodBase
 	}
 	public override bool IsStatic() => this.CallType == FuCallType.Static;
 	public bool IsAbstractOrVirtual() => this.CallType == FuCallType.Abstract || this.CallType == FuCallType.Virtual;
+	public FuVar!? FirstParameter()
+	{
+		assert this.Parameters.First is FuVar! first; // FIXME: FuVar!?
+		return IsStatic() ? first : first.NextVar();
+	}
+	public int GetParametersCount()
+	{
+		int c = this.Parameters.Count();
+		return IsStatic() ? c : c - 1;
+	}
 	public FuMethod GetDeclaringMethod()
 	{
 		FuMethod method = this;
@@ -1141,7 +1156,6 @@ public class FuMethod : FuMethodBase
 		}
 		return method;
 	}
-	public bool IsToString() => this.Name == "ToString" && this.CallType != FuCallType.Static && this.Parameters.Count() == 0;
 }
 
 class FuMethodGroup : FuMember
@@ -1210,11 +1224,6 @@ public class FuClass : FuContainerType
 		return false;
 	}
 
-	public FuClass()
-	{
-		Add(FuVar.New(new FuReadWriteClassType { Class = this }, "this")); // shadows "this" in base class
-	}
-
 	public static FuClass# New(FuCallType callType, FuId id, string name, int typeParameterCount = 0)
 		=> new FuClass { CallType = callType, Id = id, Name = name, TypeParameterCount = typeParameterCount };
 
@@ -1238,9 +1247,9 @@ public class FuClass : FuContainerType
 		return true;
 	}
 
-	public bool HasToString() => TryLookup("ToString", false) is FuMethod method && method.IsToString();
+	public bool HasToString() => TryLookup("ToString", false) is FuMethod method && method.Id == FuId.ClassToString;
 
-	public bool AddsToString() => this.Dict.ContainsKey("ToString") && this.Dict["ToString"] is FuMethod method && method.IsToString()
+	public bool AddsToString() => this.Dict.ContainsKey("ToString") && this.Dict["ToString"] is FuMethod method && method.Id == FuId.ClassToString
 		&& method.CallType != FuCallType.Override && method.CallType != FuCallType.Sealed;
 }
 

GenBase.fu

@@ -429,7 +429,7 @@ public abstract class GenBase : FuVisitor
 	protected void WriteParametersDoc!(FuMethod method)
 	{
 		bool first = true;
-		for (FuVar? param = method.Parameters.FirstParameter(); param != null; param = param.NextParameter()) {
+		for (FuVar? param = method.FirstParameter(); param != null; param = param.NextVar()) {
 			if (param.Documentation != null) {
 				WriteParameterDoc(param, first);
 				first = false;
@@ -697,14 +697,14 @@ public abstract class GenBase : FuVisitor
 
 	protected void WriteArgs!(FuMethod method, List<FuExpr#> args)
 	{
-		FuVar param = method.Parameters.FirstParameter();
+		FuVar param = method.FirstParameter();
 		bool first = true;
 		foreach (FuExpr arg in args) {
 			if (!first)
 				Write(", ");
 			first = false;
 			WriteStronglyCoerced(param.Type, arg);
-			param = param.NextParameter();
+			param = param.NextVar();
 		}
 	}
 
@@ -1884,7 +1884,7 @@ public abstract class GenBase : FuVisitor
 
 	protected void WriteRemainingParameters!(FuMethod method, bool first, bool defaultArguments)
 	{
-		for (FuVar? param = method.Parameters.FirstParameter(); param != null; param = param.NextParameter()) {
+		for (FuVar? param = method.FirstParameter(); param != null; param = param.NextVar()) {
 			if (!first)
 				Write(", ");
 			first = false;
@@ -1995,8 +1995,6 @@ public abstract class GenBase : FuVisitor
 				this.SwitchesWithGoto.Clear();
 				this.CurrentTemporaries.Clear();
 				break;
-			case FuVar _: // "this"
-				break;
 			default:
 				assert false;
 			}

GenC.fu

@@ -937,12 +937,12 @@ public class GenC : GenCCpp
 				WriteStorageTemporary(call.Method.Left);
 			}
 			assert call.Method.Symbol is FuMethod method;
-			FuVar? param = method.Parameters.FirstParameter();
+			FuVar? param = method.FirstParameter();
 			foreach (FuExpr arg in call.Arguments) {
 				WriteCTemporaries(arg);
 				if (call.Method.Symbol.Id != FuId.ConsoleWrite && call.Method.Symbol.Id != FuId.ConsoleWriteLine && !(param.Type is FuStorageType))
 					WriteStorageTemporary(arg);
-				param = param.NextParameter();
+				param = param.NextVar();
 			}
 			break;
 		default:
@@ -1635,7 +1635,7 @@ public class GenC : GenCCpp
 	void WriteArgsAndRightParenthesis!(FuMethod method, List<FuExpr#> args)
 	{
 		int i = 0;
-		for (FuVar? param = method.Parameters.FirstParameter(); param != null; param = param.NextParameter()) {
+		for (FuVar? param = method.FirstParameter(); param != null; param = param.NextVar()) {
 			if (i > 0 || method.CallType != FuCallType.Static)
 				Write(", ");
 			if (i >= args.Count)
@@ -2883,7 +2883,7 @@ public class GenC : GenCCpp
 	void WriteInstanceParameters!(FuMethod method)
 	{
 		WriteChar('(');
-		if (!method.IsMutator)
+		if (!method.IsMutator())
 			Write("const ");
 		WriteName(method.Parent);
 		Write(" *self");
@@ -3235,7 +3235,7 @@ public class GenC : GenCCpp
 		}
 		else {
 			WriteSignature(method);
-			for (FuVar? param = method.Parameters.FirstParameter(); param != null; param = param.NextParameter()) {
+			for (FuVar? param = method.FirstParameter(); param != null; param = param.NextVar()) {
 				if (NeedToDestruct(param))
 					this.VarsToDestruct.Add(param);
 			}

GenCpp.fu

@@ -1721,7 +1721,7 @@ public class GenCpp : GenCCpp
 	void WriteParametersAndConst!(FuMethod method, bool defaultArguments)
 	{
 		WriteParameters(method, defaultArguments);
-		if (method.CallType != FuCallType.Static && !method.IsMutator)
+		if (method.CallType != FuCallType.Static && !method.IsMutator())
 			Write(" const");
 	}
 

GenD.fu

@@ -1423,8 +1423,6 @@ public class GenD : GenCCppD
 				WriteMethod(method);
 				this.CurrentTemporaries.Clear();
 				break;
-			case FuVar _: // "this"
-				break;
 			default:
 				assert false;
 			}

GenJava.fu

@@ -1282,12 +1282,12 @@ public class GenJava : GenTyped
 		if (method.Id == FuId.Main && paramCount == 0)
 			Write("String[] args");
 		else {
-			FuVar param = method.Parameters.FirstParameter();
+			FuVar param = method.FirstParameter();
 			for (int i = 0; i < paramCount; i++) {
 				if (i > 0)
 					Write(", ");
 				WriteTypeAndName(param);
-				param = param.NextParameter();
+				param = param.NextVar();
 			}
 		}
 		WriteChar(')');
@@ -1297,7 +1297,7 @@ public class GenJava : GenTyped
 
 	void WriteOverloads!(FuMethod method, int paramCount)
 	{
-		if (paramCount + 1 < method.Parameters.Count())
+		if (paramCount + 1 < method.GetParametersCount())
 			WriteOverloads(method, paramCount + 1);
 		WriteSignature(method, paramCount);
 		WriteNewLine();
@@ -1306,11 +1306,11 @@ public class GenJava : GenTyped
 			Write("return ");
 		WriteName(method);
 		WriteChar('(');
-		FuVar param = method.Parameters.FirstParameter();
+		FuVar param = method.FirstParameter();
 		for (int i = 0; i < paramCount; i++) {
 			WriteName(param);
 			Write(", ");
-			param = param.NextParameter();
+			param = param.NextVar();
 		}
 		param.Value.Accept(this, FuPriority.Argument);
 		WriteLine(");");
@@ -1339,10 +1339,10 @@ public class GenJava : GenTyped
 
 	protected override void WriteMethod!(FuMethod method)
 	{
-		WriteSignature(method, method.Parameters.Count());
+		WriteSignature(method, method.GetParametersCount());
 		WriteBody(method);
 		int i = 0;
-		for (FuVar? param = method.Parameters.FirstParameter(); param != null; param = param.NextParameter()) {
+		for (FuVar? param = method.FirstParameter(); param != null; param = param.NextVar()) {
 			if (param.Value != null) {
 				WriteOverloads(method, i);
 				break;

GenSwift.fu

@@ -1620,7 +1620,7 @@ public class GenSwift : GenPySwift
 		if (method.CallType == FuCallType.Abstract)
 			WriteLine("preconditionFailure(\"Abstract method called\")");
 		else {
-			for (FuVar? param = method.Parameters.FirstParameter(); param != null; param = param.NextParameter()) {
+			for (FuVar? param = method.FirstParameter(); param != null; param = param.NextVar()) {
 				if (param.IsAssigned) {
 					Write("var ");
 					WriteTypeAndName(param);

GenTs.fu

@@ -268,7 +268,7 @@ public class GenTs : GenJs
 		WriteName(method);
 		WriteChar('(');
 		int i = 0;
-		for (FuVar? param = method.Parameters.FirstParameter(); param != null; param = param.NextParameter()) {
+		for (FuVar? param = method.FirstParameter(); param != null; param = param.NextVar()) {
 			if (i > 0)
 				Write(", ");
 			WriteName(param);

Parser.fu

@@ -847,10 +847,12 @@ public class FuParser : FuLexer
 		}
 	}
 
-	void ParseMethod!(FuMethod! method)
+	void ParseMethod!(FuClass! klass, FuMethod# method)
 	{
+		AddSymbol(klass, method);
+		method.Parameters.Parent = klass;
 		if (method.CallType != FuCallType.Static)
-			method.IsMutator = Eat(FuToken.ExclamationMark);
+			method.AddThis(klass, Eat(FuToken.ExclamationMark));
 		ExpectOrSkip(FuToken.LeftParenthesis);
 		if (!See(FuToken.RightParenthesis)) {
 			do {
@@ -944,7 +946,9 @@ public class FuParser : FuLexer
 				if (visibility == FuVisibility.Private)
 					visibility = FuVisibility.Internal; // TODO
 				klass.Constructor = new FuMethodBase { Line = call.Line, Documentation = doc, Visibility = visibility, Parent = klass,
-					Type = this.Program.System.VoidType, Name = klass.Name, IsMutator = true, Body = ParseBlock() };
+					Type = this.Program.System.VoidType, Name = klass.Name, Body = ParseBlock() };
+				klass.Constructor.Parameters.Parent = klass;
+				klass.Constructor.AddThis(klass, true);
 				continue;
 			}
 
@@ -977,9 +981,7 @@ public class FuParser : FuLexer
 					ReportError($"{CallTypeToString(callType)} method cannot be private");
 
 				FuMethod# method = new FuMethod { Line = line, Documentation = doc, Visibility = visibility, CallType = callType, TypeExpr = type, Name = name };
-				AddSymbol(klass, method);
-				method.Parameters.Parent = klass;
-				ParseMethod(method);
+				ParseMethod(klass, method);
 				continue;
 			}