[cleanup] VisitLiteral*.

13 files changed, 210 insertions, 144 deletions

diff --git a/CiResolver.cs b/CiResolver.cs
index fc4c8f4..e94d3fa 100644
--- a/CiResolver.cs
+++ b/CiResolver.cs
@@ -307,9 +307,28 @@ public class CiResolver : CiVisitor
 		return expr;
 	}
 
-	public override CiExpr Visit(CiLiteral expr, CiPriority parent)
+	public override void VisitLiteralLong(long value)
+	{
+	}
+
+	public override void VisitLiteralDouble(double value)
+	{
+	}
+
+	public override void VisitLiteralString(string value)
+	{
+	}
+
+	public override void VisitLiteralNull()
+	{
+	}
+
+	public override void VisitLiteralFalse()
+	{
+	}
+
+	public override void VisitLiteralTrue()
 	{
-		return expr;
 	}
 
 	public override CiExpr Visit(CiInterpolatedString expr, CiPriority parent)
diff --git a/CiTree.cs b/CiTree.cs
index 5048dd6..dbec8d9 100644
--- a/CiTree.cs
+++ b/CiTree.cs
@@ -69,7 +69,12 @@ public abstract class CiVisitor
 {
 	public abstract CiExpr Visit(CiCollection expr, CiPriority parent);
 	public abstract CiExpr Visit(CiVar expr, CiPriority parent);
-	public abstract CiExpr Visit(CiLiteral expr, CiPriority parent);
+	public abstract void VisitLiteralLong(long value);
+	public abstract void VisitLiteralDouble(double value);
+	public abstract void VisitLiteralString(string value);
+	public abstract void VisitLiteralNull();
+	public abstract void VisitLiteralFalse();
+	public abstract void VisitLiteralTrue();
 	public abstract CiExpr Visit(CiInterpolatedString expr, CiPriority parent);
 	public abstract CiExpr Visit(CiSymbolReference expr, CiPriority parent);
 	public abstract CiExpr Visit(CiPrefixExpr expr, CiPriority parent);
@@ -360,7 +365,6 @@ public abstract class CiLiteral : CiExpr
 
 	public static readonly CiLiteralFalse False = new CiLiteralFalse();
 	public static readonly CiLiteralTrue True = new CiLiteralTrue();
-	public override CiExpr Accept(CiVisitor visitor, CiPriority parent) => visitor.Visit(this, parent);
 	public override string ToString() => this.Value.ToString();
 }
 
@@ -372,6 +376,11 @@ public class CiLiteralLong : CiLiteral
 	public CiLiteralLong(long value) : base(value)
 	{
 	}
+	public override CiExpr Accept(CiVisitor visitor, CiPriority parent)
+	{
+		visitor.VisitLiteralLong((long) this.Value);
+		return this;
+	}
 }
 
 public class CiLiteralDouble : CiLiteral
@@ -379,6 +388,11 @@ public class CiLiteralDouble : CiLiteral
 	public CiLiteralDouble(double value) : base(value)
 	{
 	}
+	public override CiExpr Accept(CiVisitor visitor, CiPriority parent)
+	{
+		visitor.VisitLiteralDouble((double) this.Value);
+		return this;
+	}
 }
 
 public class CiLiteralString : CiLiteral
@@ -386,6 +400,11 @@ public class CiLiteralString : CiLiteral
 	public CiLiteralString(string value) : base(value)
 	{
 	}
+	public override CiExpr Accept(CiVisitor visitor, CiPriority parent)
+	{
+		visitor.VisitLiteralString((string) this.Value);
+		return this;
+	}
 }
 
 public class CiLiteralNull : CiLiteral
@@ -393,6 +412,11 @@ public class CiLiteralNull : CiLiteral
 	public CiLiteralNull() : base(null)
 	{
 	}
+	public override CiExpr Accept(CiVisitor visitor, CiPriority parent)
+	{
+		visitor.VisitLiteralNull();
+		return this;
+	}
 	public override string ToString() => "null";
 }
 
@@ -408,6 +432,11 @@ public class CiLiteralFalse : CiLiteralBool
 	public CiLiteralFalse() : base(false)
 	{
 	}
+	public override CiExpr Accept(CiVisitor visitor, CiPriority parent)
+	{
+		visitor.VisitLiteralFalse();
+		return this;
+	}
 }
 
 public class CiLiteralTrue : CiLiteralBool
@@ -415,6 +444,11 @@ public class CiLiteralTrue : CiLiteralBool
 	public CiLiteralTrue() : base(true)
 	{
 	}
+	public override CiExpr Accept(CiVisitor visitor, CiPriority parent)
+	{
+		visitor.VisitLiteralTrue();
+		return this;
+	}
 }
 
 public class CiImplicitEnumValue : CiExpr
diff --git a/GenBase.cs b/GenBase.cs
index d9ff09c..c831773 100644
--- a/GenBase.cs
+++ b/GenBase.cs
@@ -68,7 +68,7 @@ public abstract class GenBase : CiVisitor
 		this.Writer.Write(s);
 	}
 
-	protected void Write(long i)
+	public override void VisitLiteralLong(long i)
 	{
 		this.Writer.Write(i);
 	}
@@ -359,10 +359,50 @@ public abstract class GenBase : CiVisitor
 	{
 		for (int i = 0; i < array.Length; i++) {
 			WriteComma(i);
-			Write(array[i]);
+			VisitLiteralLong(array[i]);
 		}
 	}
 
+	public override void VisitLiteralDouble(double value)
+	{
+		string s = value.ToString("R", CultureInfo.InvariantCulture);
+		Write(s);
+		foreach (char c in s) {
+			switch (c) {
+			case '-':
+			case '0':
+			case '1':
+			case '2':
+			case '3':
+			case '4':
+			case '5':
+			case '6':
+			case '7':
+			case '8':
+			case '9':
+				break;
+			default:
+				return;
+			}
+		}
+		Write(".0"); // it looked like an integer
+	}
+
+	public override void VisitLiteralNull()
+	{
+		Write("null");
+	}
+
+	public override void VisitLiteralFalse()
+	{
+		Write("false");
+	}
+
+	public override void VisitLiteralTrue()
+	{
+		Write("true");
+	}
+
 	protected void WriteEscapedChar(char c, bool quoted = true)
 	{
 		switch (c) {
@@ -379,58 +419,40 @@ public abstract class GenBase : CiVisitor
 		}
 	}
 
-	protected virtual void WriteLiteral(object value)
+	public override void VisitLiteralString(string value)
+	{
+		Write('"');
+		foreach (char c in value)
+			WriteEscapedChar(c);
+		Write('"');
+	}
+
+	protected void WriteLiteral(object value)
 	{
 		switch (value) {
 		case null:
-			Write("null");
+			VisitLiteralNull();
 			break;
 		case long l:
-			Write(l);
+			VisitLiteralLong(l);
 			break;
 		case bool b:
-			Write(b ? "true" : "false");
+			if (b)
+				VisitLiteralTrue();
+			else
+				VisitLiteralFalse();
 			break;
 		case string s:
-			Write('"');
-			foreach (char c in s)
-				WriteEscapedChar(c);
-			Write('"');
+			VisitLiteralString(s);
 			break;
 		case double d:
-			string s2 = d.ToString("R", CultureInfo.InvariantCulture);
-			Write(s2);
-			foreach (char c in s2) {
-				switch (c) {
-				case '-':
-				case '0':
-				case '1':
-				case '2':
-				case '3':
-				case '4':
-				case '5':
-				case '6':
-				case '7':
-				case '8':
-				case '9':
-					break;
-				default:
-					return;
-				}
-			}
-			Write(".0"); // it looked like an integer
+			VisitLiteralDouble(d);
 			break;
 		default:
 			throw new NotImplementedException(value.GetType().Name);
 		}
 	}
 
-	public override CiExpr Visit(CiLiteral expr, CiPriority parent)
-	{
-		WriteLiteral(expr.Value);
-		return expr;
-	}
-
 	protected abstract void WriteName(CiSymbol symbol);
 
 	protected virtual TypeCode GetIntegerTypeCode(CiIntegerType integer, bool promote)
@@ -511,10 +533,10 @@ public abstract class GenBase : CiVisitor
 	protected virtual void WritePrintfWidth(CiInterpolatedPart part)
 	{
 		if (part.WidthExpr != null)
-			Write(part.Width);
+			VisitLiteralLong(part.Width);
 		if (part.Precision >= 0) {
 			Write('.');
-			Write(part.Precision);
+			VisitLiteralLong(part.Precision);
 		}
 	}
 
@@ -633,16 +655,16 @@ public abstract class GenBase : CiVisitor
 			WriteCoercedInternal(type, expr, parent);
 	}
 
-	protected virtual void WriteCoercedLiteral(CiType type, object value)
+	protected virtual void WriteCoercedLiteral(CiType type, CiLiteral literal)
 	{
-		WriteLiteral(value);
+		WriteLiteral(literal.Value);
 	}
 
 	protected void WriteCoercedLiterals(CiType type, CiExpr[] exprs)
 	{
 		for (int i = 0; i < exprs.Length; i++) {
 			WriteComma(i);
-			WriteCoercedLiteral(type, ((CiLiteral) exprs[i]).Value);
+			WriteCoercedLiteral(type, (CiLiteral) exprs[i]);
 		}
 	}
 
@@ -787,13 +809,13 @@ public abstract class GenBase : CiVisitor
 		Write("for (");
 		Write(intString);
 		Write(" _i");
-		Write(nesting);
+		VisitLiteralLong(nesting);
 		Write(" = 0; _i");
-		Write(nesting);
+		VisitLiteralLong(nesting);
 		Write(" < ");
-		Write(count);
+		VisitLiteralLong(count);
 		Write("; _i");
-		Write(nesting);
+		VisitLiteralLong(nesting);
 		Write("++) ");
 		OpenBlock();
 	}
@@ -803,7 +825,7 @@ public abstract class GenBase : CiVisitor
 		WriteLocalName(def, CiPriority.Primary);
 		for (int i = 0; i < nesting; i++) {
 			Write("[_i");
-			Write(i);
+			VisitLiteralLong(i);
 			Write(']');
 		}
 	}
@@ -887,7 +909,7 @@ public abstract class GenBase : CiVisitor
 				return;
 			}
 			if (right is CiLiteral rightLiteral) {
-				Write(leftValue + (long) rightLiteral.Value);
+				VisitLiteralLong(leftValue + (long) rightLiteral.Value);
 				return;
 			}
 		}
diff --git a/GenC.cs b/GenC.cs
index c297147..1d7821f 100644
--- a/GenC.cs
+++ b/GenC.cs
@@ -80,12 +80,9 @@ public class GenC : GenCCpp
 		Include("stdbool.h");
 	}
 
-	protected override void WriteLiteral(object value)
+	public override void VisitLiteralNull()
 	{
-		if (value == null)
-			Write("NULL");
-		else
-			base.WriteLiteral(value);
+		Write("NULL");
 	}
 
 	protected override void WritePrintfWidth(CiInterpolatedPart part)
@@ -267,7 +264,7 @@ public class GenC : GenCCpp
 		Write("CiMatch_GetPos(");
 		expr.Left.Accept(this, CiPriority.Argument);
 		Write(", ");
-		Write(which);
+		VisitLiteralLong(which);
 		Write(')');
 	}
 
@@ -427,7 +424,7 @@ public class GenC : GenCCpp
 		while (type is CiArrayType array) {
 			if (type is CiArrayStorageType arrayStorage) {
 				Write('[');
-				Write(arrayStorage.Length);
+				VisitLiteralLong(arrayStorage.Length);
 				Write(']');
 			}
 			else if (array.ElementType is CiArrayStorageType)
@@ -686,7 +683,7 @@ public class GenC : GenCCpp
 		int id = this.CurrentTemporaries.IndexOf(type);
 		if (id < 0) {
 			id = this.CurrentTemporaries.Count;
-			WriteDefinition(type, () => { Write("citemp"); Write(id); }, false, true);
+			WriteDefinition(type, () => { Write("citemp"); VisitLiteralLong(id); }, false, true);
 			if (assign) {
 				Write(" = ");
 				if (expr != null)
@@ -699,7 +696,7 @@ public class GenC : GenCCpp
 		}
 		else if (assign) {
 			Write("citemp");
-			Write(id);
+			VisitLiteralLong(id);
 			Write(" = ");
 			if (expr != null)
 				WriteCoerced(type, expr, CiPriority.Argument);
@@ -1024,7 +1021,7 @@ public class GenC : GenCCpp
 			int tempId = this.CurrentTemporaries.IndexOf(expr);
 			if (tempId >= 0) {
 				Write("citemp");
-				Write(tempId);
+				VisitLiteralLong(tempId);
 			}
 			else
 				expr.Accept(this, CiPriority.Primary);
@@ -1074,9 +1071,9 @@ public class GenC : GenCCpp
 		Write("memcmp(");
 		WriteArrayPtrAdd(ptr, offset);
 		Write(", ");
-		WriteLiteral(literal);
+		VisitLiteralString(literal);
 		Write(", ");
-		Write(literal.Length);
+		VisitLiteralLong(literal.Length);
 		Write(')');
 		Write(GetEqOp(not));
 		Write('0');
@@ -1111,7 +1108,7 @@ public class GenC : GenCCpp
 					Write('(');
 				lengthExpr.Accept(this, CiPriority.Equality);
 				Write(" != ");
-				Write(rightValue.Length);
+				VisitLiteralLong(rightValue.Length);
 				Write(" || ");
 				WriteSubstringEqual(cast, ptr, offset, rightValue, CiPriority.CondOr, true);
 				if (parent > CiPriority.CondOr)
@@ -1122,7 +1119,7 @@ public class GenC : GenCCpp
 					Write('(');
 				lengthExpr.Accept(this, CiPriority.Equality);
 				Write(" == ");
-				Write(rightValue.Length);
+				VisitLiteralLong(rightValue.Length);
 				Write(" && ");
 				WriteSubstringEqual(cast, ptr, offset, rightValue, CiPriority.CondAnd, false);
 				if (parent > CiPriority.CondAnd || parent == CiPriority.CondOr)
@@ -1169,7 +1166,7 @@ public class GenC : GenCCpp
 	{
 		Write("for (int _i = 0; _i < ");
 		if (args.Length == 1)
-			Write(((CiArrayStorageType) obj.Type).Length);
+			VisitLiteralLong(((CiArrayStorageType) obj.Type).Length);
 		else
 			args[2].Accept(this, CiPriority.Rel); // FIXME: side effect in every iteration
 		WriteLine("; _i++)");
@@ -1192,7 +1189,7 @@ public class GenC : GenCCpp
 		if (elementType is CiClass klass && NeedsConstructor(klass)) {
 			WriteName(klass);
 			Write("_Construct(&citemp");
-			Write(id);
+			VisitLiteralLong(id);
 			WriteLine(");");
 		}
 		Write(function);
@@ -1203,7 +1200,7 @@ public class GenC : GenCCpp
 			args[0].Accept(this, CiPriority.Argument);
 		}
 		Write(", citemp");
-		Write(id);
+		VisitLiteralLong(id);
 		Write(')');
 		this.CurrentTemporaries[id] = elementType;
 	}
@@ -1427,7 +1424,7 @@ public class GenC : GenCCpp
 				WriteArrayPtrAdd(obj, args[1]);
 			Write(", ");
 			if (args.Length == 1)
-				Write(((CiArrayStorageType) array).Length);
+				VisitLiteralLong(((CiArrayStorageType) array).Length);
 			else
 				args[2].Accept(this, CiPriority.Primary);
 			WriteSizeofCompare(array);
@@ -1484,7 +1481,7 @@ public class GenC : GenCCpp
 				Write("qsort(");
 				WriteArrayPtr(obj, CiPriority.Argument);
 				Write(", ");
-				Write(arrayStorage.Length);
+				VisitLiteralLong(arrayStorage.Length);
 				Write(", sizeof(");
 				Write(typeCode);
 				Write(')');
@@ -1856,13 +1853,13 @@ public class GenC : GenCCpp
 		int nesting = 0;
 		while (type is CiArrayStorageType array) {
 			Write("for (int _i");
-			Write(nesting);
+			VisitLiteralLong(nesting);
 			Write(" = ");
-			Write(array.Length - 1);
+			VisitLiteralLong(array.Length - 1);
 			Write("; _i");
-			Write(nesting);
+			VisitLiteralLong(nesting);
 			Write(" >= 0; _i");
-			Write(nesting);
+			VisitLiteralLong(nesting);
 			WriteLine("--)");
 			this.Indent++;
 			nesting++;
@@ -1895,7 +1892,7 @@ public class GenC : GenCCpp
 		WriteLocalName(symbol, CiPriority.Primary);
 		for (int i = 0; i < nesting; i++) {
 			Write("[_i");
-			Write(i);
+			VisitLiteralLong(i);
 			Write(']');
 		}
 		if (type is CiListType)
@@ -2053,7 +2050,7 @@ public class GenC : GenCCpp
 			Write(" = 0; ");
 			WriteCamelCaseNotKeyword(element);
 			Write(" < ");
-			Write(array.Length);
+			VisitLiteralLong(array.Length);
 			Write("; ");
 			WriteCamelCaseNotKeyword(element);
 			Write("++)");
@@ -2945,7 +2942,7 @@ public class GenC : GenCCpp
 			Write(' ');
 			WriteResource(name, -1);
 			Write('[');
-			Write(resources[name].Length);
+			VisitLiteralLong(resources[name].Length);
 			WriteLine("] = {");
 			Write('\t');
 			Write(resources[name]);
diff --git a/GenCCpp.cs b/GenCCpp.cs
index 6aa29d4..d9b2568 100644
--- a/GenCCpp.cs
+++ b/GenCCpp.cs
@@ -1,6 +1,6 @@
 // GenCCpp.cs - C/C++ code generator
 //
-// Copyright (C) 2011-2021  Piotr Fusik
+// Copyright (C) 2011-2022  Piotr Fusik
 //
 // This file is part of CiTo, see https://github.com/pfusik/cito
 //
@@ -242,7 +242,7 @@ public abstract class GenCCpp : GenTyped
 			int gotoId = this.StringSwitchesWithGoto.IndexOf(switchStatement);
 			if (gotoId >= 0) {
 				Write("goto ciafterswitch");
-				Write(gotoId);
+				VisitLiteralLong(gotoId);
 				WriteLine(';');
 				return;
 			}
@@ -304,7 +304,7 @@ public abstract class GenCCpp : GenTyped
 		}
 		if (gotoId >= 0) {
 			Write("ciafterswitch");
-			Write(gotoId);
+			VisitLiteralLong(gotoId);
 			WriteLine(": ;");
 		}
 	}
diff --git a/GenCl.cs b/GenCl.cs
index 47b7249..166d76e 100644
--- a/GenCl.cs
+++ b/GenCl.cs
@@ -112,7 +112,7 @@ public class GenCl : GenC
 		}
 		WriteArrayPtrAdd(ptr, offset);
 		Write(", ");
-		WriteLiteral(literal);
+		VisitLiteralString(literal);
 		Write(')');
 	}
 
diff --git a/GenCpp.cs b/GenCpp.cs
index bfde597..b412ecb 100644
--- a/GenCpp.cs
+++ b/GenCpp.cs
@@ -44,12 +44,9 @@ public class GenCpp : GenCCpp
 		Include("cmath");
 	}
 
-	protected override void WriteLiteral(object value)
+	public override void VisitLiteralNull()
 	{
-		if (value == null)
-			Write("nullptr");
-		else
-			base.WriteLiteral(value);
+		Write("nullptr");
 	}
 
 	public override CiExpr Visit(CiInterpolatedString expr, CiPriority parent)
@@ -253,7 +250,7 @@ public class GenCpp : GenCCpp
 			Write("std::array<");
 			Write(arrayStorage.ElementType, false);
 			Write(", ");
-			Write(arrayStorage.Length);
+			VisitLiteralLong(arrayStorage.Length);
 			Write('>');
 			break;
 		case CiListType list:
@@ -524,7 +521,7 @@ public class GenCpp : GenCCpp
 
 					if (part.Prefix.Length > 0) {
 						Write(" << ");
-						WriteLiteral(part.Prefix);
+						VisitLiteralString(part.Prefix);
 					}
 
 					Write(" << ");
@@ -543,7 +540,7 @@ public class GenCpp : GenCCpp
 						WriteStringLiteralWithNewLine(interpolated.Suffix);
 						return;
 					}
-					WriteLiteral(interpolated.Suffix);
+					VisitLiteralString(interpolated.Suffix);
 				}
 			}
 			else {
@@ -1292,7 +1289,7 @@ public class GenCpp : GenCCpp
 			Include("array");
 			Include("cstdint");
 			Write("const std::array<uint8_t, ");
-			Write(resources[name].Length);
+			VisitLiteralLong(resources[name].Length);
 			Write("> ");
 			WriteResource(name, -1);
 			if (define) {
diff --git a/GenCs.cs b/GenCs.cs
index 09c4b83..841cf64 100644
--- a/GenCs.cs
+++ b/GenCs.cs
@@ -270,9 +270,9 @@ public class GenCs : GenTyped
 		}
 	}
 
-	protected override void WriteCoercedLiteral(CiType type, object value)
+	protected override void WriteCoercedLiteral(CiType type, CiLiteral literal)
 	{
-		WriteLiteral(value);
+		WriteLiteral(literal.Value);
 		if (type == CiSystem.FloatType)
 			Write('f');
 	}
@@ -286,13 +286,13 @@ public class GenCs : GenTyped
 			part.Argument.Accept(this, CiPriority.Argument);
 			if (part.WidthExpr != null) {
 				Write(',');
-				Write(part.Width);
+				VisitLiteralLong(part.Width);
 			}
 			if (part.Format != ' ') {
 				Write(':');
 				Write(part.Format);
 				if (part.Precision >= 0)
-					Write(part.Precision);
+					VisitLiteralLong(part.Precision);
 			}
 			Write('}');
 		}
@@ -507,7 +507,7 @@ public class GenCs : GenTyped
 				Write(", ");
 				if (args.Length == 1) {
 					Write("0, ");
-					Write(((CiArrayStorageType) obj.Type).Length);
+					VisitLiteralLong(((CiArrayStorageType) obj.Type).Length);
 				}
 				else {
 					args[1].Accept(this, CiPriority.Argument);
diff --git a/GenJava.cs b/GenJava.cs
index 5351730..299c5fb 100644
--- a/GenJava.cs
+++ b/GenJava.cs
@@ -29,10 +29,10 @@ public class GenJava : GenTyped
 {
 	string OutputDirectory;
 
-	protected override void WriteLiteral(object value)
+	public override void VisitLiteralLong(long value)
 	{
-		base.WriteLiteral(value);
-		if (value is long l && l != (int) l)
+		base.VisitLiteralLong(value);
+		if (value != (int) value)
 			Write('L');
 	}
 
@@ -42,7 +42,7 @@ public class GenJava : GenTyped
 			if (part.WidthExpr != null)
 				throw new NotImplementedException("Cannot format integer with both width and precision");
 			Write('0');
-			Write(part.Precision);
+			VisitLiteralLong(part.Precision);
 		}
 		else
 			base.WritePrintfWidth(part);
@@ -371,9 +371,9 @@ public class GenJava : GenTyped
 	protected override void WriteResource(string name, int length)
 	{
 		Write("CiResource.getByteArray(");
-		WriteLiteral(name);
+		VisitLiteralString(name);
 		Write(", ");
-		Write(length);
+		VisitLiteralLong(length);
 		Write(')');
 	}
 
@@ -435,7 +435,7 @@ public class GenJava : GenTyped
 				Write('(');
 			WriteIndexingInternal(leftBinary); // omit "& 0xff"
 			Write(GetEqOp(not));
-			Write((sbyte) l);
+			VisitLiteralLong((sbyte) l);
 			if (parent > CiPriority.Equality)
 				Write(')');
 		}
@@ -448,12 +448,12 @@ public class GenJava : GenTyped
 		return type is CiRangeType range && range.Min >= 0 && range.Max > sbyte.MaxValue && range.Max <= byte.MaxValue;
 	}
 
-	protected override void WriteCoercedLiteral(CiType type, object value)
+	protected override void WriteCoercedLiteral(CiType type, CiLiteral literal)
 	{
 		if (IsUnsignedByte(type))
-			Write((sbyte) (long) value);
+			VisitLiteralLong((sbyte) (long) literal.Value);
 		else {
-			WriteLiteral(value);
+			WriteLiteral(literal.Value);
 			if (type == CiSystem.FloatType)
 				Write('f');
 		}
@@ -467,7 +467,7 @@ public class GenJava : GenTyped
 				Write('(');
 			base.WriteIndexing(leftBinary, CiPriority.And);
 			Write(" & ");
-			Write(0xff & (long) rightLiteral.Value);
+			VisitLiteralLong(0xff & (long) rightLiteral.Value);
 			if (parent > CiPriority.CondAnd && parent != CiPriority.And)
 				Write(')');
 		}
@@ -863,7 +863,7 @@ public class GenJava : GenTyped
 			WriteUppercaseWithUnderscores(konst.Name);
 			Write(" = ");
 			if (konst.Value is CiImplicitEnumValue imp)
-				Write(imp.Value);
+				VisitLiteralLong(imp.Value);
 			else
 				konst.Value.Accept(this, CiPriority.Argument);
 			WriteLine(';');
diff --git a/GenJs.cs b/GenJs.cs
index 448118b..2e328b6 100644
--- a/GenJs.cs
+++ b/GenJs.cs
@@ -180,20 +180,20 @@ public class GenJs : GenBase
 					case 'E':
 						Write(".toExponential(");
 						if (part.Precision >= 0)
-							Write(part.Precision);
+							VisitLiteralLong(part.Precision);
 						Write(").toUpperCase()");
 						break;
 					case 'e':
 						Write(".toExponential(");
 						if (part.Precision >= 0)
-							Write(part.Precision);
+							VisitLiteralLong(part.Precision);
 						Write(')');
 						break;
 					case 'F':
 					case 'f':
 						Write(".toFixed(");
 						if (part.Precision >= 0)
-							Write(part.Precision);
+							VisitLiteralLong(part.Precision);
 						Write(')');
 						break;
 					case 'X':
@@ -208,18 +208,18 @@ public class GenJs : GenBase
 					}
 					if (part.Precision >= 0 && "DdXx".IndexOf(part.Format) >= 0) {
 						Write(".padStart(");
-						Write(part.Precision);
+						VisitLiteralLong(part.Precision);
 						Write(", \"0\")");
 					}
 				}
 				if (part.Width > 0) {
 					Write(".padStart(");
-					Write(part.Width);
+					VisitLiteralLong(part.Width);
 					Write(')');
 				}
 				else if (part.Width < 0) {
 					Write(".padEnd(");
-					Write(-part.Width);
+					VisitLiteralLong(-part.Width);
 					Write(')');
 				}
 			}
@@ -728,7 +728,7 @@ public class GenJs : GenBase
 			Write(konst.Documentation);
 			WriteUppercaseWithUnderscores(konst.Name);
 			Write(" : ");
-			Write(konst.Value.IntValue);
+			VisitLiteralLong(konst.Value.IntValue);
 		}
 		WriteLine();
 		CloseBlock();
diff --git a/GenPy.cs b/GenPy.cs
index 921337f..eee9ec8 100644
--- a/GenPy.cs
+++ b/GenPy.cs
@@ -84,19 +84,19 @@ public class GenPy : GenPySwift
 		WriteLine("\"\"\"");
 	}
 
-	protected override void WriteLiteral(object value)
+	public override void VisitLiteralNull()
 	{
-		switch (value) {
-		case null:
-			Write("None");
-			break;
-		case bool b:
-			Write(b ? "True" : "False");
-			break;
-		default:
-			base.WriteLiteral(value);
-			break;
-		}
+		Write("None");
+	}
+
+	public override void VisitLiteralFalse()
+	{
+		Write("False");
+	}
+
+	public override void VisitLiteralTrue()
+	{
+		Write("True");
 	}
 
 	void WriteNameNotKeyword(string name)
@@ -223,16 +223,16 @@ public class GenPy : GenPySwift
 				if (part.Width >= 0) {
 					if (!(part.Argument.Type is CiNumericType))
 						Write('>');
-					Write(part.Width);
+					VisitLiteralLong(part.Width);
 				}
 				else {
 					Write('<');
-					Write(-part.Width);
+					VisitLiteralLong(-part.Width);
 				}
 			}
 			if (part.Precision >= 0) {
 				Write(part.Argument.Type is CiIntegerType ? '0' : '.');
-				Write(part.Precision);
+				VisitLiteralLong(part.Precision);
 			}
 			if (part.Format != ' ' && part.Format != 'D')
 				Write(part.Format);
@@ -855,7 +855,7 @@ public class GenPy : GenPySwift
 	void WriteInclusiveLimit(CiExpr limit, int increment, string incrementString)
 	{
 		if (limit is CiLiteral literal)
-			Write((long) literal.Value + increment);
+			VisitLiteralLong((long) literal.Value + increment);
 		else {
 			limit.Accept(this, CiPriority.Add);
 			Write(incrementString);
@@ -885,7 +885,7 @@ public class GenPy : GenPySwift
 		}
 		if (rangeStep != 1) {
 			Write(", ");
-			Write(rangeStep);
+			VisitLiteralLong(rangeStep);
 		}
 		Write(')');
 	}
@@ -1020,7 +1020,7 @@ public class GenPy : GenPySwift
 		foreach (CiConst konst in enu) {
 			WriteUppercaseWithUnderscores(konst.Name);
 			Write(" = ");
-			Write(konst.Value.IntValue);
+			VisitLiteralLong(konst.Value.IntValue);
 			WriteLine();
 			Write(konst.Documentation);
 		}
diff --git a/GenPySwift.cs b/GenPySwift.cs
index 5439038..c6a38f8 100644
--- a/GenPySwift.cs
+++ b/GenPySwift.cs
@@ -266,7 +266,7 @@ public abstract class GenPySwift : GenBase
 	void OpenWhileTrue()
 	{
 		Write("while ");
-		WriteLiteral(true);
+		VisitLiteralTrue();
 		OpenChild();
 	}
 
diff --git a/GenSwift.cs b/GenSwift.cs
index 02b9d52..5adf5de 100644
--- a/GenSwift.cs
+++ b/GenSwift.cs
@@ -310,12 +310,9 @@ public class GenSwift : GenPySwift
 		}
 	}
 
-	protected override void WriteLiteral(object value)
+	public override void VisitLiteralNull()
 	{
-		if (value == null)
-			Write("nil");
-		else
-			base.WriteLiteral(value);
+		Write("nil");
 	}
 
 	void WriteInterpolatedLiteral(string s)
@@ -518,7 +515,7 @@ public class GenSwift : GenPySwift
 		else if (obj.Type is CiArrayStorageType arrayStorage && method == CiSystem.CollectionSortAll) {
 			obj.Accept(this, CiPriority.Primary);
 			Write("[0..<");
-			Write(arrayStorage.Length);
+			VisitLiteralLong(arrayStorage.Length);
 			Write("].sort()");
 		}
 		else if (method == CiSystem.CollectionSortPart) {
@@ -751,7 +748,7 @@ public class GenSwift : GenPySwift
 			Write("](repeating: ");
 			WriteDefaultValue(array.ElementType);
 			Write(", count: ");
-			Write(array.Length);
+			VisitLiteralLong(array.Length);
 			Write(')');
 		}
 	}
@@ -1119,7 +1116,7 @@ public class GenSwift : GenPySwift
 				throw new NotImplementedException(cond.Op.ToString());
 			}
 			Write(", by: ");
-			Write(rangeStep);
+			VisitLiteralLong(rangeStep);
 			Write(')');
 		}
 	}
@@ -1245,7 +1242,7 @@ public class GenSwift : GenPySwift
 					Write("[]");
 				else {
 					Write("rawValue: ");
-					Write(i);
+					VisitLiteralLong(i);
 				}
 				WriteLine(')');
 			}
@@ -1272,7 +1269,7 @@ public class GenSwift : GenPySwift
 					WriteName(konst);
 					if (!(konst.Value is CiImplicitEnumValue)) {
 						Write(" = ");
-						Write(i);
+						VisitLiteralLong(i);
 					}
 					valueToConst.Add(i, konst);
 				}