37 files changed, 248 insertions(+), 224 deletions(-)

M Core/NosSmooth.PacketSerializersGenerator/ConverterDeserializationGenerator.cs
M Core/NosSmooth.PacketSerializersGenerator/Extensions/ParameterInfoExtensions.cs
M Core/NosSmooth.PacketSerializersGenerator/InlineConverterGenerators/BasicInlineConverterGenerator.cs
M Core/NosSmooth.PacketSerializersGenerator/InlineConverterGenerators/BoolInlineConverterGenerator.cs
M Core/NosSmooth.PacketSerializersGenerator/InlineConverterGenerators/EnumInlineConverterGenerator.cs
M Core/NosSmooth.PacketSerializersGenerator/InlineConverterGenerators/FallbackInlineConverterGenerator.cs
M Core/NosSmooth.PacketSerializersGenerator/InlineConverterGenerators/StringInlineConverterGenerator.cs
M Core/NosSmooth.PacketSerializersGenerator/PacketConverterGenerator.cs
M Core/NosSmooth.PacketSerializersGenerator/SourceGenerator.cs
M Core/NosSmooth.Packets/Converters/BaseStringConverter.cs
M Core/NosSmooth.Packets/Converters/Basic/BasicTypeConverter.cs
M Core/NosSmooth.Packets/Converters/Basic/BoolStringConverter.cs
M Core/NosSmooth.Packets/Converters/Basic/ByteStringConverter.cs
M Core/NosSmooth.Packets/Converters/Basic/CharStringConverter.cs
M Core/NosSmooth.Packets/Converters/Basic/IntStringConverter.cs
M Core/NosSmooth.Packets/Converters/Basic/LongStringConverter.cs
M Core/NosSmooth.Packets/Converters/Basic/ShortStringConverter.cs
M Core/NosSmooth.Packets/Converters/Basic/StringTypeConverter.cs
M Core/NosSmooth.Packets/Converters/Basic/UIntStringConverter.cs
M Core/NosSmooth.Packets/Converters/Basic/ULongStringConverter.cs
M Core/NosSmooth.Packets/Converters/Basic/UShortStringConverter.cs
M Core/NosSmooth.Packets/Converters/Common/NameStringConverter.cs
M Core/NosSmooth.Packets/Converters/IStringConverter.cs
M Core/NosSmooth.Packets/Converters/IStringSerializer.cs
M Core/NosSmooth.Packets/Converters/Packets/UpgradeRareSubPacketConverter.cs
A Core/NosSmooth.Packets/Converters/Special/EnumTypeConverter.cs
A Core/NosSmooth.Packets/Converters/Special/ISpecialTypeConverter.cs
A Core/NosSmooth.Packets/Converters/Special/ListTypeConverter.cs
A Core/NosSmooth.Packets/Converters/Special/NullableTypeConverter.cs
A Core/NosSmooth.Packets/Converters/TypeConverterRepository.cs
M Core/NosSmooth.Packets/Errors/CouldNotConvertError.cs
M Core/NosSmooth.Packets/NosSmooth.Packets.csproj
M Core/NosSmooth.Packets/PacketSerializer.cs
M Core/NosSmooth.Packets/PacketStringEnumerator.cs
M Core/NosSmooth.Packets/PacketToken.cs
M Tests/NosSmooth.Packets.Tests/PacketStringBuilderTests.cs
M Tests/NosSmooth.Packets.Tests/PacketStringEnumeratorTests.cs

@@ 94,7 94,7 @@ public class ConverterDeserializationGenerator
         _textWriter.WriteLine($@"while ({_stringEnumeratorVariable}.IsOnLastToken() == false)");
         _textWriter.WriteLine("{");
         _textWriter.Indent++;
-        _textWriter.WriteLine($"{_stringEnumeratorVariable}.GetNextToken();");
+        _textWriter.WriteLine($"{_stringEnumeratorVariable}.GetNextToken(out _);");
         _textWriter.Indent--;
         _textWriter.WriteLine("}");
     }

@@ 38,6 38,16 @@ public static class ParameterInfoExtensions
     }
 
     /// <summary>
+    /// Gets the name of the token variable.
+    /// </summary>
+    /// <param name="parameterInfo">The parameter.</param>
+    /// <returns>The name of the token variable.</returns>
+    public static string GetTokenVariableName(this ParameterInfo parameterInfo)
+    {
+        return $"{parameterInfo.Name}Token";
+    }
+
+    /// <summary>
     /// Gets the name of the error variable.
     /// </summary>
     /// <param name="parameterInfo">The parameter.</param>

@@ 91,4 91,4 @@ public static Result<{type}?> ParseBasic{type}(IStringConverter typeConverter, P
 ");
         }
     }
-}>
\ No newline at end of file
+}

@@ 70,4 70,4 @@ public static Result<bool?> ParseBool(PacketStringEnumerator stringEnumerator)
 }}
 ");
     }
-}>
\ No newline at end of file
+}

@@ 105,4 105,4 @@ public static Result<{type}?> ParseEnum{type.ToString().Replace('.', '_')}(IStri
             );
         }
     }
-}>
\ No newline at end of file
+}

@@ 58,4 58,4 @@ public class FallbackInlineConverterGenerator : IInlineConverterGenerator
     {
         // ignore
     }
-}>
\ No newline at end of file
+}

@@ 53,4 53,4 @@ public static Result<string?> ParseString(PacketStringEnumerator stringEnumerato
 "
         );
     }
-}>
\ No newline at end of file
+}

@@ 95,7 95,7 @@ public override Result Serialize({_packetInfo.Name}? obj, PacketStringBuilder bu
 }}
 
 /// <inheritdoc />
-public override Result<{_packetInfo.Name}?> Deserialize(PacketStringEnumerator stringEnumerator)
+public override Result<{_packetInfo.Name}?> Deserialize(ref PacketStringEnumerator stringEnumerator)
 {{
     var typeConverter = this;
 "


@@ 176,7 176,7 @@ public override Result<{_packetInfo.Name}?> Deserialize(PacketStringEnumerator s
                     textWriter.WriteLine("IResultError? skipError;");
                     skipped = true;
                 }
-                textWriter.WriteLine($@"skipResult = stringEnumerator.GetNextToken();");
+                textWriter.WriteLine($@"skipResult = stringEnumerator.GetNextToken(out _);");
                 textWriter.WriteLine
                     ("skipError = CheckDeserializationResult(result, \"None\", stringEnumerator, false);");
                 textWriter.WriteMultiline


@@ 246,4 246,4 @@ public override Result<{_packetInfo.Name}?> Deserialize(PacketStringEnumerator s
 
         return null;
     }
-}>
\ No newline at end of file
+}

@@ 130,6 130,11 @@ public class SourceGenerator : ISourceGenerator
                     $"{packetRecord.GetPrefix()}.{packetRecord.Identifier.NormalizeWhitespace().ToFullString()}Converter.g.cs",
                     stringWriter.GetStringBuilder().ToString()
                 );
+                File.WriteAllText
+                (
+                    $"/tmp/{packetRecord.GetPrefix()}.{packetRecord.Identifier.NormalizeWhitespace().ToFullString()}Converter.g.cs",
+                    stringWriter.GetStringBuilder().ToString()
+                );
             }
         }
 

@@ 19,12 19,12 @@ public abstract class BaseStringConverter<TParseType> : IStringConverter<TParseT
     public abstract Result Serialize(TParseType? obj, PacketStringBuilder builder);
 
     /// <inheritdoc />
-    public abstract Result<TParseType?> Deserialize(PacketStringEnumerator stringEnumerator);
+    public abstract Result<TParseType?> Deserialize(ref PacketStringEnumerator stringEnumerator);
 
     /// <inheritdoc/>
-    Result<object?> IStringConverter.Deserialize(PacketStringEnumerator stringEnumerator)
+    Result<object?> IStringConverter.Deserialize(ref PacketStringEnumerator stringEnumerator)
     {
-        var result = Deserialize(stringEnumerator);
+        var result = Deserialize(ref stringEnumerator);
         if (!result.IsSuccess)
         {
             return Result<object?>.FromError(result);


@@ 43,4 43,4 @@ public abstract class BaseStringConverter<TParseType> : IStringConverter<TParseT
 
         return Serialize(parseType, builder);
     }
-}>
\ No newline at end of file
+}

@@ 23,20 23,20 @@ public abstract class BasicTypeConverter<TBasicType> : BaseStringConverter<TBasi
     }
 
     /// <inheritdoc />
-    public override Result<TBasicType?> Deserialize(PacketStringEnumerator stringEnumerator)
+    public override Result<TBasicType?> Deserialize(ref PacketStringEnumerator stringEnumerator)
     {
-        var nextTokenResult = stringEnumerator.GetNextToken();
+        var nextTokenResult = stringEnumerator.GetNextToken(out var packetToken);
         if (!nextTokenResult.IsSuccess)
         {
             return Result<TBasicType?>.FromError(nextTokenResult);
         }
 
-        if (nextTokenResult.Entity.Token == "-")
+        if (packetToken.Token[0] == '-' && packetToken.Token.Length == 1)
         {
             return Result<TBasicType?>.FromSuccess(default);
         }
 
-        return Deserialize(nextTokenResult.Entity.Token);
+        return Deserialize(packetToken.Token);
     }
 
     /// <summary>


@@ 44,5 44,5 @@ public abstract class BasicTypeConverter<TBasicType> : BaseStringConverter<TBasi
     /// </summary>
     /// <param name="value">The value to deserialize.</param>
     /// <returns>The deserialized value or an error.</returns>
-    protected abstract Result<TBasicType?> Deserialize(string value);
+    protected abstract Result<TBasicType?> Deserialize(ReadOnlySpan<char> value);
 }=
\ No newline at end of file

@@ 22,19 22,14 @@ public class BoolStringConverter : BaseStringConverter<bool>
     }
 
     /// <inheritdoc />
-    public override Result<bool> Deserialize(PacketStringEnumerator stringEnumerator)
+    public override Result<bool> Deserialize(ref PacketStringEnumerator stringEnumerator)
     {
-        var nextTokenResult = stringEnumerator.GetNextToken();
+        var nextTokenResult = stringEnumerator.GetNextToken(out var packetToken);
         if (!nextTokenResult.IsSuccess)
         {
             return Result<bool>.FromError(nextTokenResult);
         }
 
-        if (nextTokenResult.Entity.Token == "-")
-        {
-            return Result<bool>.FromSuccess(default);
-        }
-
-        return nextTokenResult.Entity.Token == "1" ? true : false;
+        return packetToken.Token[0] == '1' ? true : false;
     }
 }=
\ No newline at end of file

@@ 4,6 4,7 @@
 //  Copyright (c) František Boháček. All rights reserved.
 //  Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System;
 using NosSmooth.Packets.Errors;
 using Remora.Results;
 


@@ 15,11 16,11 @@ namespace NosSmooth.Packets.Converters.Basic;
 public class ByteStringConverter : BasicTypeConverter<byte>
 {
     /// <inheritdoc />
-    protected override Result<byte> Deserialize(string value)
+    protected override Result<byte> Deserialize(ReadOnlySpan<char> value)
     {
         if (!byte.TryParse(value, out var parsed))
         {
-            return new CouldNotConvertError(this, value, "Could not parse as an byte.");
+            return new CouldNotConvertError(this, value.ToString(), "Could not parse as an byte.");
         }
 
         return parsed;

@@ 4,6 4,7 @@
 //  Copyright (c) František Boháček. All rights reserved.
 //  Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System;
 using NosSmooth.Packets.Errors;
 using Remora.Results;
 


@@ 15,11 16,11 @@ namespace NosSmooth.Packets.Converters.Basic;
 public class CharStringConverter : BasicTypeConverter<char>
 {
     /// <inheritdoc />
-    protected override Result<char> Deserialize(string value)
+    protected override Result<char> Deserialize(ReadOnlySpan<char> value)
     {
         if (value.Length != 1)
         {
-            return new CouldNotConvertError(this, value, "The token is not one character long.");
+            return new CouldNotConvertError(this, value.ToString(), "The token is not one character long.");
         }
 
         return value[0];

@@ 4,6 4,7 @@
 //  Copyright (c) František Boháček. All rights reserved.
 //  Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System;
 using NosSmooth.Packets.Errors;
 using Remora.Results;
 


@@ 15,11 16,11 @@ namespace NosSmooth.Packets.Converters.Basic;
 public class IntStringConverter : BasicTypeConverter<int>
 {
     /// <inheritdoc />
-    protected override Result<int> Deserialize(string value)
+    protected override Result<int> Deserialize(ReadOnlySpan<char> value)
     {
         if (!int.TryParse(value, out var parsed))
         {
-            return new CouldNotConvertError(this, value, "Could not parse as int.");
+            return new CouldNotConvertError(this, value.ToString(), "Could not parse as int.");
         }
 
         return parsed;

@@ 4,6 4,7 @@
 //  Copyright (c) František Boháček. All rights reserved.
 //  Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System;
 using NosSmooth.Packets.Errors;
 using Remora.Results;
 


@@ 15,11 16,11 @@ namespace NosSmooth.Packets.Converters.Basic;
 public class LongStringConverter : BasicTypeConverter<long>
 {
     /// <inheritdoc />
-    protected override Result<long> Deserialize(string value)
+    protected override Result<long> Deserialize(ReadOnlySpan<char> value)
     {
         if (!long.TryParse(value, out var parsed))
         {
-            return new CouldNotConvertError(this, value, "Could not parse as a long.");
+            return new CouldNotConvertError(this, value.ToString(), "Could not parse as a long.");
         }
 
         return parsed;

@@ 4,6 4,7 @@
 //  Copyright (c) František Boháček. All rights reserved.
 //  Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System;
 using NosSmooth.Packets.Errors;
 using Remora.Results;
 


@@ 15,11 16,11 @@ namespace NosSmooth.Packets.Converters.Basic;
 public class ShortStringConverter : BasicTypeConverter<short>
 {
     /// <inheritdoc />
-    protected override Result<short> Deserialize(string value)
+    protected override Result<short> Deserialize(ReadOnlySpan<char> value)
     {
         if (!short.TryParse(value, out var parsed))
         {
-            return new CouldNotConvertError(this, value, "Could not parse as short.");
+            return new CouldNotConvertError(this, value.ToString(), "Could not parse as short.");
         }
 
         return parsed;

@@ 4,6 4,7 @@
 //  Copyright (c) František Boháček. All rights reserved.
 //  Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System;
 using Remora.Results;
 
 namespace NosSmooth.Packets.Converters.Basic;


@@ 14,8 15,8 @@ namespace NosSmooth.Packets.Converters.Basic;
 public class StringTypeConverter : BasicTypeConverter<string>
 {
     /// <inheritdoc />
-    protected override Result<string?> Deserialize(string value)
+    protected override Result<string?> Deserialize(ReadOnlySpan<char> value)
     {
-        return value;
+        return value.ToString();
     }
 }=
\ No newline at end of file

@@ 4,6 4,7 @@
 //  Copyright (c) František Boháček. All rights reserved.
 //  Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System;
 using NosSmooth.Packets.Errors;
 using Remora.Results;
 


@@ 15,11 16,11 @@ namespace NosSmooth.Packets.Converters.Basic;
 public class UIntStringConverter : BasicTypeConverter<uint>
 {
     /// <inheritdoc />
-    protected override Result<uint> Deserialize(string value)
+    protected override Result<uint> Deserialize(ReadOnlySpan<char> value)
     {
         if (!uint.TryParse(value, out var parsed))
         {
-            return new CouldNotConvertError(this, value, "Could not parse as uint");
+            return new CouldNotConvertError(this, value.ToString(), "Could not parse as uint");
         }
 
         return parsed;

@@ 4,6 4,7 @@
 //  Copyright (c) František Boháček. All rights reserved.
 //  Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System;
 using NosSmooth.Packets.Errors;
 using Remora.Results;
 


@@ 15,11 16,11 @@ namespace NosSmooth.Packets.Converters.Basic;
 public class ULongStringConverter : BasicTypeConverter<ulong>
 {
     /// <inheritdoc />
-    protected override Result<ulong> Deserialize(string value)
+    protected override Result<ulong> Deserialize(ReadOnlySpan<char> value)
     {
         if (!ulong.TryParse(value, out var parsed))
         {
-            return new CouldNotConvertError(this, value, "Could not parse as an ulong.");
+            return new CouldNotConvertError(this, value.ToString(), "Could not parse as an ulong.");
         }
 
         return parsed;

@@ 4,6 4,7 @@
 //  Copyright (c) František Boháček. All rights reserved.
 //  Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System;
 using NosSmooth.Packets.Errors;
 using Remora.Results;
 


@@ 15,11 16,11 @@ namespace NosSmooth.Packets.Converters.Basic;
 public class UShortStringConverter : BasicTypeConverter<ushort>
 {
     /// <inheritdoc />
-    protected override Result<ushort> Deserialize(string value)
+    protected override Result<ushort> Deserialize(ReadOnlySpan<char> value)
     {
         if (!ushort.TryParse(value, out var parsed))
         {
-            return new CouldNotConvertError(this, value, "Could not parse as an ushort.");
+            return new CouldNotConvertError(this, value.ToString(), "Could not parse as an ushort.");
         }
 
         return parsed;

@@ 29,19 29,19 @@ public class NameStringConverter : BaseStringConverter<NameString>
     }
 
     /// <inheritdoc />
-    public override Result<NameString?> Deserialize(PacketStringEnumerator stringEnumerator)
+    public override Result<NameString?> Deserialize(ref PacketStringEnumerator stringEnumerator)
     {
-        var tokenResult = stringEnumerator.GetNextToken();
+        var tokenResult = stringEnumerator.GetNextToken(out var packetToken);
         if (!tokenResult.IsSuccess)
         {
             return Result<NameString?>.FromError(tokenResult);
         }
 
-        if (tokenResult.Entity.Token == "-")
+        if (packetToken.Token[0] == '-' && packetToken.Token.Length == 1)
         {
             return Result<NameString?>.FromSuccess(null);
         }
 
-        return NameString.FromPacket(tokenResult.Entity.Token);
+        return NameString.FromPacket(packetToken.Token.ToString());
     }
 }=
\ No newline at end of file

@@ 18,7 18,7 @@ public interface IStringConverter
     /// </summary>
     /// <param name="stringEnumerator">The packet string enumerator with the current position.</param>
     /// <returns>The parsed object or an error.</returns>
-    public Result<object?> Deserialize(PacketStringEnumerator stringEnumerator);
+    public Result<object?> Deserialize(ref PacketStringEnumerator stringEnumerator);
 
     /// <summary>
     /// Serializes the given object to string by appending to the packet string builder.


@@ 43,7 43,7 @@ public interface IStringConverter<TParseType> : IStringConverter
     /// </summary>
     /// <param name="stringEnumerator">The packet string enumerator with the current position.</param>
     /// <returns>The parsed object or an error.</returns>
-    public new Result<TParseType?> Deserialize(PacketStringEnumerator stringEnumerator);
+    public new Result<TParseType?> Deserialize(ref PacketStringEnumerator stringEnumerator);
 
     /// <summary>
     /// Serializes the given object to string by appending to the packet string builder.

@@ 20,7 20,7 @@ public interface IStringSerializer
     /// <param name="parseType">The type of the object to serialize.</param>
     /// <param name="stringEnumerator">The packet string enumerator with the current position.</param>
     /// <returns>The parsed object or an error.</returns>
-    public Result<object?> Deserialize(Type parseType, PacketStringEnumerator stringEnumerator);
+    public Result<object?> Deserialize(Type parseType, ref PacketStringEnumerator stringEnumerator);
 
     /// <summary>
     /// Serializes the given object to string by appending to the packet string builder.


@@ 37,7 37,7 @@ public interface IStringSerializer
     /// <param name="stringEnumerator">The packet string enumerator with the current position.</param>
     /// <typeparam name="TParseType">The type of the object to serialize.</typeparam>
     /// <returns>The parsed object or an error.</returns>
-    public Result<TParseType?> Deserialize<TParseType>(PacketStringEnumerator stringEnumerator);
+    public Result<TParseType?> Deserialize<TParseType>(ref PacketStringEnumerator stringEnumerator);
 
     /// <summary>
     /// Serializes the given object to string by appending to the packet string builder.

@@ 28,31 28,31 @@ public class UpgradeRareSubPacketConverter : BaseStringConverter<UpgradeRareSubP
     }
 
     /// <inheritdoc />
-    public override Result<UpgradeRareSubPacket?> Deserialize(PacketStringEnumerator stringEnumerator)
+    public override Result<UpgradeRareSubPacket?> Deserialize(ref PacketStringEnumerator stringEnumerator)
     {
-        var tokenResult = stringEnumerator.GetNextToken();
+        var tokenResult = stringEnumerator.GetNextToken(out var packetToken);
         if (!tokenResult.IsSuccess)
         {
             return Result<UpgradeRareSubPacket?>.FromError(tokenResult);
         }
+        var token = packetToken.Token;
 
-        var token = tokenResult.Entity.Token;
         if (token.Length > 3)
         {
-            return new CouldNotConvertError(this, token, "The string is not two/three characters long.");
+            return new CouldNotConvertError(this, token.ToString(), "The string is not two/three characters long.");
         }
 
-        var upgradeString = token.Substring(0, token.Length - 1);
-        var rareString = token[token.Length - 1].ToString();
+        var upgradeString = token.Slice(0, token.Length - 1);
+        var rareString = token.Slice(token.Length - 1);
 
         if (!byte.TryParse(upgradeString, out var upgrade))
         {
-            return new CouldNotConvertError(this, upgradeString, "Could not parse as byte");
+            return new CouldNotConvertError(this, upgradeString.ToString(), "Could not parse as byte");
         }
 
         if (!sbyte.TryParse(rareString, out var rare))
         {
-            return new CouldNotConvertError(this, rareString, "Could not parse as byte");
+            return new CouldNotConvertError(this, rareString.ToString(), "Could not parse as byte");
         }
 
         return new UpgradeRareSubPacket(upgrade, rare);

@@ 5,6 5,7 @@
 //  Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
 using System;
+using System.Buffers;
 using NosSmooth.Packets.Converters;
 using Remora.Results;
 

@@ 2,9 2,9 @@
 
     <PropertyGroup>
         <LangVersion>10</LangVersion>
-        <TargetFrameworks>net6.0;netstandard2.0</TargetFrameworks>
         <AssemblyName>NosSmooth.Packets</AssemblyName>
         <RootNamespace>NosSmooth.Packets</RootNamespace>
+        <TargetFrameworks>net6.0;netstandard2.1</TargetFrameworks>
     </PropertyGroup>
 
     <ItemGroup>

@@ 59,20 59,20 @@ public class PacketSerializer : IPacketSerializer
     public Result<IPacket> Deserialize(string packetString, PacketSource preferredSource)
     {
         var packetStringEnumerator = new PacketStringEnumerator(packetString);
-        var headerTokenResult = packetStringEnumerator.GetNextToken();
+        var headerTokenResult = packetStringEnumerator.GetNextToken(out var packetToken);
         if (!headerTokenResult.IsSuccess)
         {
             return Result<IPacket>.FromError(headerTokenResult);
         }
 
-        var packetInfoResult = _packetTypesRepository.FindPacketInfo(headerTokenResult.Entity.Token, preferredSource);
+        var packetInfoResult = _packetTypesRepository.FindPacketInfo(packetToken.Token.ToString(), preferredSource);
         if (!packetInfoResult.IsSuccess)
         {
             return Result<IPacket>.FromError(packetInfoResult);
         }
 
         var packetInfo = packetInfoResult.Entity;
-        var deserializedResult = packetInfo.PacketConverter.Deserialize(packetStringEnumerator);
+        var deserializedResult = packetInfo.PacketConverter.Deserialize(ref packetStringEnumerator);
         if (!deserializedResult.IsSuccess)
         {
             return Result<IPacket>.FromError(deserializedResult);

@@ 4,6 4,7 @@
 //  Copyright (c) František Boháček. All rights reserved.
 //  Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System;
 using System.Collections.Generic;
 using System.Text;
 using NosSmooth.Packets.Errors;


@@ 14,15 15,18 @@ namespace NosSmooth.Packets;
 /// <summary>
 /// Enumerator for packet strings.
 /// </summary>
-public struct PacketStringEnumerator
+public ref struct PacketStringEnumerator
 {
-    private readonly EnumeratorData _data;
+    private readonly ReadOnlySpan<char> _data;
     private readonly Dictionary<char, ushort> _numberOfSeparators;
     private EnumeratorLevel _currentLevel;
     private (char Separator, uint? MaxTokens)? _preparedLevel;
-    private PacketToken? _currentToken;
+    private bool _currentTokenRead;
+    private PacketToken _currentToken;
     private bool _readToLast;
 
+    private int _cursor;
+
     /// <summary>
     /// Initializes a new instance of the <see cref="PacketStringEnumerator"/> struct.
     /// </summary>


@@ 31,30 35,14 @@ public struct PacketStringEnumerator
     public PacketStringEnumerator(string data, char separator = ' ')
     {
         _currentLevel = new EnumeratorLevel(null, separator);
-        _data = new EnumeratorData(data);
+        _data = new ReadOnlySpan<char>(data.ToCharArray());
+        _cursor = 0;
         _numberOfSeparators = new Dictionary<char, ushort>();
         _numberOfSeparators.Add(separator, 1);
-        _currentToken = null;
-        _preparedLevel = null;
-        _readToLast = false;
-    }
-
-    /// <summary>
-    /// Initializes a new instance of the <see cref="PacketStringEnumerator"/> struct.
-    /// </summary>
-    /// <param name="data">The data of the enumerator.</param>
-    /// <param name="level">The current enumerator level.</param>
-    /// <param name="numberOfSeparators">The number of separators.</param>
-    private PacketStringEnumerator(EnumeratorData data, EnumeratorLevel level, Dictionary<char, ushort> numberOfSeparators)
-    {
-        _currentLevel = level;
-        _data = data;
-
-        // TODO: use something less heavy than copying everything from the dictionary.
-        _numberOfSeparators = new Dictionary<char, ushort>(numberOfSeparators);
-        _currentToken = null;
+        _currentToken = new PacketToken(default, default, default, default);
         _preparedLevel = null;
         _readToLast = false;
+        _currentTokenRead = false;
     }
 
     /// <summary>


@@ 66,7 54,7 @@ public struct PacketStringEnumerator
     /// <param name="separator">The separator to look for.</param>
     public void SetAfterSeparatorOnce(char separator)
     {
-        _currentToken = null;
+        _currentTokenRead = false;
         _currentLevel.SeparatorOnce = separator;
     }
 


@@ 97,19 85,6 @@ public struct PacketStringEnumerator
     }
 
     /// <summary>
-    /// Create next level with the separator given in the prepared level.
-    /// </summary>
-    /// <remarks>
-    /// Level of the current enumerator will stay the same.
-    /// Will return null, if there is not a level prepared.
-    /// </remarks>
-    /// <returns>An enumerator with the new level pushed.</returns>
-    public PacketStringEnumerator? CreatePreparedLevel()
-    {
-        return _preparedLevel is not null ? CreateLevel(_preparedLevel.Value.Separator, _preparedLevel.Value.MaxTokens) : null;
-    }
-
-    /// <summary>
     /// Push next level with the separator given in the prepared level.
     /// </summary>
     /// <returns>Whether there is a prepared level present.</returns>


@@ 120,7 95,7 @@ public struct PacketStringEnumerator
             return false;
         }
 
-        _currentToken = null;
+        _currentTokenRead = false;
         _currentLevel = new EnumeratorLevel(_currentLevel, _preparedLevel.Value.Separator, _preparedLevel.Value.MaxTokens)
         {
             ReachedEnd = _currentLevel.ReachedEnd


@@ 136,25 111,6 @@ public struct PacketStringEnumerator
     }
 
     /// <summary>
-    /// Create next level with the given separator and maximum number of tokens.
-    /// </summary>
-    /// <remarks>
-    /// Level of the current enumerator will stay the same.
-    /// The maximum number of tokens indicates how many tokens can be read ie. in lists,
-    /// the enumerator won't allow reading more than that many tokens, error will be thrown if the user tries to read more.
-    /// </remarks>
-    /// <param name="separator">The separator of the new level.</param>
-    /// <param name="maxTokens">The maximum number of tokens to read.</param>
-    /// <returns>An enumerator with the new level pushed.</returns>
-    public PacketStringEnumerator CreateLevel(char separator, uint? maxTokens = default)
-    {
-        _currentToken = null;
-        var stringEnumerator = new PacketStringEnumerator(_data, _currentLevel, _numberOfSeparators);
-        stringEnumerator.PushLevel(separator, maxTokens);
-        return stringEnumerator;
-    }
-
-    /// <summary>
     /// Push new separator level to the stack.
     /// </summary>
     /// <remarks>


@@ 166,7 122,7 @@ public struct PacketStringEnumerator
     public void PushLevel(char separator, uint? maxTokens = default)
     {
         _preparedLevel = null;
-        _currentToken = null;
+        _currentTokenRead = false;
         _currentLevel = new EnumeratorLevel(_currentLevel, separator, maxTokens)
         {
             ReachedEnd = _currentLevel.ReachedEnd


@@ 197,36 153,50 @@ public struct PacketStringEnumerator
     }
 
     /// <summary>
+    /// Skip the given amount of characters.
+    /// </summary>
+    /// <param name="count">The count of characters to skip.</param>
+    public void Skip(int count)
+    {
+        _cursor += count;
+    }
+
+    /// <summary>
     /// Get the next token.
     /// </summary>
+    /// <param name="packetToken">The resulting token.</param>
     /// <param name="seek">Whether to seek the cursor to the end of the token.</param>
     /// <returns>The found token.</returns>
-    public Result<PacketToken> GetNextToken(bool seek = true)
+    public Result GetNextToken(out PacketToken packetToken, bool seek = true)
     {
         // The token is cached if seek was false to speed things up.
-        if (_currentToken != null)
+        if (_currentTokenRead)
         {
-            var cachedToken = _currentToken.Value;
+            var cachedToken = _currentToken;
             if (seek)
             {
                 UpdateCurrentAndParentLevels(cachedToken);
                 _currentLevel.TokensRead++;
-                _currentToken = null;
-                _data.Cursor += cachedToken.Token.Length + 1;
+                _currentTokenRead = false;
+                _cursor += cachedToken.Token.Length + 1;
                 _currentLevel.SeparatorOnce = null;
             }
 
-            return cachedToken;
+            packetToken = new PacketToken(default, default, default, default);
+            packetToken = cachedToken;
+            return Result.FromSuccess();
         }
 
-        if (_data.ReachedEnd || (_currentLevel.ReachedEnd ?? false))
+        if ((_cursor >= _data.Length) || (_currentLevel.ReachedEnd ?? false))
         {
-            return new PacketEndReachedError(_data.Data, _currentLevel.ReachedEnd ?? false);
+            packetToken = new PacketToken(default, default, default, default);
+            return new PacketEndReachedError(_data.ToString(), _currentLevel.ReachedEnd ?? false);
         }
 
-        var currentIndex = _data.Cursor;
-        char currentCharacter = _data.Data[currentIndex];
-        StringBuilder tokenString = new StringBuilder();
+        var currentIndex = _cursor;
+        var length = 0;
+        var startIndex = currentIndex;
+        char currentCharacter = _data[currentIndex];
 
         bool? isLast, encounteredUpperLevel;
 


@@ 234,27 204,27 @@ public struct PacketStringEnumerator
         // If should read to last, then read until isLast is null or true.
         while (!IsSeparator(currentCharacter, out isLast, out encounteredUpperLevel) || (_readToLast && !(isLast ?? true)))
         {
-            tokenString.Append(currentCharacter);
+            length++;
             currentIndex++;
 
-            if (currentIndex == _data.Data.Length)
+            if (currentIndex >= _data.Length)
             {
                 isLast = true;
                 encounteredUpperLevel = true;
                 break;
             }
 
-            currentCharacter = _data.Data[currentIndex];
+            currentCharacter = _data[currentIndex];
         }
 
         _readToLast = false;
         currentIndex++;
 
-        var token = new PacketToken(tokenString.ToString(), isLast, encounteredUpperLevel, _data.ReachedEnd);
+        var token = new PacketToken(_data.Slice(startIndex, length), isLast, encounteredUpperLevel, _cursor >= _data.Length);
         if (seek)
         {
             UpdateCurrentAndParentLevels(token);
-            _data.Cursor = currentIndex;
+            _cursor = currentIndex;
             _currentLevel.TokensRead++;
         }
         else


@@ 262,7 232,8 @@ public struct PacketStringEnumerator
             _currentToken = token;
         }
 
-        return token;
+        packetToken = token;
+        return Result.FromSuccess();
     }
 
     /// <summary>


@@ 312,7 283,7 @@ public struct PacketStringEnumerator
     /// <returns>Whether the last token was read. Null if cannot determine (ie. there are multiple levels with the same separator.)</returns>
     public bool? IsOnLastToken()
     {
-        if (_data.ReachedEnd)
+        if (_cursor >= _data.Length)
         {
             return true;
         }


@@ 376,21 347,6 @@ public struct PacketStringEnumerator
         return true;
     }
 
-    private class EnumeratorData
-    {
-        public EnumeratorData(string data)
-        {
-            Data = data;
-            Cursor = 0;
-        }
-
-        public string Data { get; }
-
-        public int Cursor { get; set; }
-
-        public bool ReachedEnd => Cursor >= Data.Length;
-    }
-
     private class EnumeratorLevel
     {
         public EnumeratorLevel(EnumeratorLevel? parent, char separator, uint? maxTokens = default)

@@ 4,6 4,7 @@
 //  Copyright (c) František Boháček. All rights reserved.
 //  Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
+using System;
 using System.Diagnostics.CodeAnalysis;
 
 namespace NosSmooth.Packets;


@@ 11,9 12,52 @@ namespace NosSmooth.Packets;
 /// <summary>
 /// The single token from a packet.
 /// </summary>
-/// <param name="Token">The token.</param>
-/// <param name="IsLast">Whether the token is last in the current level. Null if it cannot be determined.</param>
-/// <param name="EncounteredUpperLevel">Whether the current separator was from an upper stack level than the parent. That could mean some kind of an error if not etc. at the end of parsing a last entry of a list and last entry of a subpacket.</param>
-/// <param name="PacketEndReached">Whether the packet's end was reached.</param>
-[SuppressMessage("StyleCop.CSharp.NamingRules", "SA1313:Parameter names should begin with lower-case letter", Justification = "Record struct creates the underlying properties.")]
-public readonly record struct PacketToken(string Token, bool? IsLast, bool? EncounteredUpperLevel, bool PacketEndReached);>
\ No newline at end of file
+[SuppressMessage
+(
+    "StyleCop.CSharp.NamingRules",
+    "SA1313:Parameter names should begin with lower-case letter",
+    Justification = "Record struct creates the underlying properties."
+)]
+public readonly ref struct PacketToken
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="PacketToken"/> struct.
+    /// </summary>
+    /// <param name="token">The token.</param>
+    /// <param name="isLast">Whether this is the last token in the current level.</param>
+    /// <param name="encounteredUpperLevel">Whether upper level separator was encountered.</param>
+    /// <param name="packetEndReached">Whether the packet end was reached.</param>
+    public PacketToken
+    (
+        ReadOnlySpan<char> token,
+        bool? isLast,
+        bool? encounteredUpperLevel,
+        bool packetEndReached
+    )
+    {
+        Token = token;
+        IsLast = isLast;
+        EncounteredUpperLevel = encounteredUpperLevel;
+        PacketEndReached = packetEndReached;
+    }
+
+    /// <summary>
+    /// The token.
+    /// </summary>
+    public ReadOnlySpan<char> Token { get; }
+
+    /// <summary>
+    /// Whether the token is last in the current level. Null if it cannot be determined.
+    /// </summary>
+    public bool? IsLast { get; }
+
+    /// <summary>
+    /// Whether the current separator was from an upper stack level than the parent. That could mean some kind of an error if not etc. at the end of parsing a last entry of a list and last entry of a subpacket.
+    /// </summary>
+    public bool? EncounteredUpperLevel { get; }
+
+    /// <summary>
+    /// Whether the packet's end was reached.
+    /// </summary>
+    public bool PacketEndReached { get; }
+}<
\ No newline at end of file

@@ 55,7 55,6 @@ public class PacketStringBuilderTests
         stringBuilder.Append("a");
         stringBuilder.Append("b");
         stringBuilder.Append("c");
-        stringBuilder.ReplaceWithParentSeparator();
         stringBuilder.PopLevel();
         stringBuilder.Append("d");
 

@@ 23,64 23,65 @@ public class PacketStringEnumeratorTests
     public void EnumeratorListComplexStringGivesCorrectResult()
     {
         var stringEnumerator = new PacketStringEnumerator("in 1 11.12.13|14.15.16|17.18.19");
-        var headerTokenResult = stringEnumerator.GetNextToken();
+        var headerTokenResult = stringEnumerator.GetNextToken(out var packetToken);
         Assert.True(headerTokenResult.IsSuccess);
-        Assert.False(headerTokenResult.Entity.PacketEndReached);
-        Assert.NotNull(headerTokenResult.Entity.IsLast);
-        Assert.NotNull(headerTokenResult.Entity.EncounteredUpperLevel);
-        Assert.False(headerTokenResult.Entity.IsLast);
-        Assert.False(headerTokenResult.Entity.EncounteredUpperLevel);
-        Assert.Matches("in", headerTokenResult.Entity.Token);
-
-        var firstToken = stringEnumerator.GetNextToken();
+        Assert.False(packetToken.PacketEndReached);
+        Assert.NotNull(packetToken.IsLast);
+        Assert.NotNull(packetToken.EncounteredUpperLevel);
+        Assert.False(packetToken.IsLast);
+        Assert.False(packetToken.EncounteredUpperLevel);
+        Assert.Matches("in", packetToken.Token.ToString());
+
+        var firstToken = stringEnumerator.GetNextToken(out packetToken);
         Assert.True(firstToken.IsSuccess);
-        Assert.False(firstToken.Entity.PacketEndReached);
-        Assert.NotNull(firstToken.Entity.IsLast);
-        Assert.NotNull(firstToken.Entity.EncounteredUpperLevel);
-        Assert.False(firstToken.Entity.IsLast);
-        Assert.False(firstToken.Entity.EncounteredUpperLevel);
-        Assert.Matches("1", firstToken.Entity.Token);
+        Assert.False(packetToken.PacketEndReached);
+        Assert.NotNull(packetToken.IsLast);
+        Assert.NotNull(packetToken.EncounteredUpperLevel);
+        Assert.False(packetToken.IsLast);
+        Assert.False(packetToken.EncounteredUpperLevel);
+        Assert.Matches("1", packetToken.Token.ToString());
 
-        var listEnumerator = stringEnumerator.CreateLevel('|');
-        listEnumerator.PrepareLevel('.');
+        stringEnumerator.PushLevel('|');
+        stringEnumerator.PrepareLevel('.');
 
         for (int i = 0; i < 3; i++)
         {
-            var preparedLevel = listEnumerator.CreatePreparedLevel();
-            Assert.NotNull(preparedLevel);
+            stringEnumerator.PushPreparedLevel();
 
             for (int j = 0; j < 3; j++)
             {
                 string currentNum = (j + (i * 3) + 1 + 10).ToString();
-                var currentToken = preparedLevel!.Value.GetNextToken();
+                var currentToken = stringEnumerator.GetNextToken(out packetToken);
                 Assert.True(currentToken.IsSuccess);
-                Assert.False(currentToken.Entity.PacketEndReached);
-                Assert.NotNull(currentToken.Entity.IsLast);
-                Assert.NotNull(currentToken.Entity.EncounteredUpperLevel);
+                Assert.False(packetToken.PacketEndReached);
+                Assert.NotNull(packetToken.IsLast);
+                Assert.NotNull(packetToken.EncounteredUpperLevel);
                 if (j == 2 && i == 2)
                 {
-                    Assert.True(currentToken.Entity.EncounteredUpperLevel);
+                    Assert.True(packetToken.EncounteredUpperLevel);
                 }
                 else
                 {
-                    Assert.False(currentToken.Entity.EncounteredUpperLevel);
+                    Assert.False(packetToken.EncounteredUpperLevel);
                 }
 
                 if (j != 2)
                 {
-                    Assert.False(currentToken.Entity.IsLast);
+                    Assert.False(packetToken.IsLast);
                 }
                 else
                 {
-                    Assert.True(currentToken.Entity.IsLast);
+                    Assert.True(packetToken.IsLast);
                 }
 
-                Assert.Matches(currentNum, currentToken.Entity.Token);
+                Assert.Matches(currentNum, packetToken.Token.ToString());
             }
 
-            Assert.True(preparedLevel!.Value.IsOnLastToken());
+            Assert.True(stringEnumerator.IsOnLastToken());
+            stringEnumerator.PopLevel();
         }
 
+        stringEnumerator.PopLevel();
         Assert.True(stringEnumerator.IsOnLastToken());
     }
 


@@ 91,18 92,18 @@ public class PacketStringEnumeratorTests
     public void EnumeratorDoesNotAllowOvereachingPacketEnd()
     {
         var stringEnumerator = new PacketStringEnumerator("in 1 2 3 4");
-        var tokenResult = stringEnumerator.GetNextToken();
+        var tokenResult = stringEnumerator.GetNextToken(out _);
         Assert.True(tokenResult.IsSuccess); // in
-        tokenResult = stringEnumerator.GetNextToken();
+        tokenResult = stringEnumerator.GetNextToken(out _);
         Assert.True(tokenResult.IsSuccess); // 1
-        tokenResult = stringEnumerator.GetNextToken();
+        tokenResult = stringEnumerator.GetNextToken(out _);
         Assert.True(tokenResult.IsSuccess); // 2
-        tokenResult = stringEnumerator.GetNextToken();
+        tokenResult = stringEnumerator.GetNextToken(out _);
         Assert.True(tokenResult.IsSuccess); // 3
-        tokenResult = stringEnumerator.GetNextToken();
+        tokenResult = stringEnumerator.GetNextToken(out _);
         Assert.True(tokenResult.IsSuccess); // 4
 
-        tokenResult = stringEnumerator.GetNextToken();
+        tokenResult = stringEnumerator.GetNextToken(out _);
         Assert.False(tokenResult.IsSuccess);
         Assert.IsType<PacketEndReachedError>(tokenResult.Error);
     }


@@ 114,20 115,20 @@ public class PacketStringEnumeratorTests
     public void EnumeratorDoesNotAllowOvereachingListComplexTypeEnd()
     {
         var stringEnumerator = new PacketStringEnumerator("in 1|2.2|3.3|4.4|5");
-        var tokenResult = stringEnumerator.GetNextToken();
+        var tokenResult = stringEnumerator.GetNextToken(out _);
         Assert.True(tokenResult.IsSuccess); // in
 
-        var listEnumerator = stringEnumerator.CreateLevel('.');
-        var itemEnumerator = listEnumerator.CreateLevel('|');
+        stringEnumerator.PushLevel('.');
+        stringEnumerator.PushLevel('|');
 
-        tokenResult = itemEnumerator.GetNextToken();
+        tokenResult = stringEnumerator.GetNextToken(out _);
         Assert.True(tokenResult.IsSuccess); // 1
 
-        tokenResult = itemEnumerator.GetNextToken();
+        tokenResult = stringEnumerator.GetNextToken(out var packetToken);
         Assert.True(tokenResult.IsSuccess); // 2
-        Assert.True(tokenResult.Entity.IsLast);
+        Assert.True(packetToken.IsLast);
 
-        tokenResult = itemEnumerator.GetNextToken();
+        tokenResult = stringEnumerator.GetNextToken(out _);
         Assert.False(tokenResult.IsSuccess);
         Assert.IsType<PacketEndReachedError>(tokenResult.Error);
         Assert.True(((PacketEndReachedError)tokenResult.Error!).LevelEnd);


@@ 140,33 141,37 @@ public class PacketStringEnumeratorTests
     public void EnumeratorDoesNotAllowOvereachingListLength()
     {
         var stringEnumerator = new PacketStringEnumerator("in 1|2.2|3.3|4.4|5");
-        var tokenResult = stringEnumerator.GetNextToken();
+        var tokenResult = stringEnumerator.GetNextToken(out _);
         Assert.True(tokenResult.IsSuccess); // in
 
-        var listEnumerator = stringEnumerator.CreateLevel('.', 2);
-        var itemEnumerator = listEnumerator.CreateLevel('|');
+        stringEnumerator.PushLevel('.', 2);
+        stringEnumerator.PushLevel('|');
 
         // first item
-        tokenResult = itemEnumerator.GetNextToken();
+        tokenResult = stringEnumerator.GetNextToken(out _);
         Assert.True(tokenResult.IsSuccess);
 
-        tokenResult = itemEnumerator.GetNextToken();
+        tokenResult = stringEnumerator.GetNextToken(out var packetToken);
         Assert.True(tokenResult.IsSuccess);
-        Assert.True(tokenResult.Entity.IsLast);
+        Assert.True(packetToken.IsLast);
+
+        stringEnumerator.PopLevel();
 
         // second item
-        itemEnumerator = listEnumerator.CreateLevel('|');
-        tokenResult = itemEnumerator.GetNextToken();
+        stringEnumerator.PushLevel('|');
+        tokenResult = stringEnumerator.GetNextToken(out _);
         Assert.True(tokenResult.IsSuccess);
 
-        tokenResult = itemEnumerator.GetNextToken();
+        stringEnumerator.GetNextToken(out packetToken);
         Assert.True(tokenResult.IsSuccess);
-        Assert.True(tokenResult.Entity.IsLast);
+        Assert.True(packetToken.IsLast);
+
+        stringEnumerator.PopLevel();
 
         // cannot reach third item
-        Assert.True(listEnumerator.IsOnLastToken());
-        itemEnumerator = listEnumerator.CreateLevel('|');
-        tokenResult = itemEnumerator.GetNextToken();
+        Assert.True(stringEnumerator.IsOnLastToken());
+        stringEnumerator.PushLevel('|');
+        tokenResult = stringEnumerator.GetNextToken(out _);
         Assert.False(tokenResult.IsSuccess);
         Assert.IsType<PacketEndReachedError>(tokenResult.Error);
         Assert.True(((PacketEndReachedError)tokenResult.Error!).LevelEnd);


@@ 179,18 184,18 @@ public class PacketStringEnumeratorTests
     public void EnumeratorReturnsEncounteredUpperLevel()
     {
         var stringEnumerator = new PacketStringEnumerator("in 1|2 1");
-        var tokenResult = stringEnumerator.GetNextToken();
+        var tokenResult = stringEnumerator.GetNextToken(out _);
         Assert.True(tokenResult.IsSuccess); // in
 
-        var listEnumerator = stringEnumerator.CreateLevel('.');
-        var itemEnumerator = listEnumerator.CreateLevel('|');
+        stringEnumerator.PushLevel('.');
+        stringEnumerator.PushLevel('|');
 
-        tokenResult = itemEnumerator.GetNextToken();
+        tokenResult = stringEnumerator.GetNextToken(out _);
         Assert.True(tokenResult.IsSuccess);
 
-        tokenResult = itemEnumerator.GetNextToken();
+        tokenResult = stringEnumerator.GetNextToken(out var packetToken);
         Assert.True(tokenResult.IsSuccess);
-        Assert.True(tokenResult.Entity.IsLast);
-        Assert.True(tokenResult.Entity.EncounteredUpperLevel);
+        Assert.True(packetToken.IsLast);
+        Assert.True(packetToken.EncounteredUpperLevel);
     }
 }=
\ No newline at end of file