Use ubuntu for the CI

Eliminate various string allocations

.github/workflows/ci.yml

@@ -11,22 +11,24 @@ on:
 
 jobs:
   build:
-    runs-on: windows-latest
+    runs-on: ubuntu-latest
 
     steps:
     - name: Checkout
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
       with:
         submodules: true
         fetch-depth: 0
 
-    - name: Install .NET 6.0
-      uses: actions/setup-dotnet@v1
+    - name: Install .NET 6.0, and 8.0
+      uses: actions/setup-dotnet@v4
       with:
-        dotnet-version: '6.0.x'
+        dotnet-version: |
+          6.0.x
+          8.0.x
 
     - name: Build, Test, Pack, Publish
       shell: bash
       run: |
-        dotnet tool install -g dotnet-releaser
+        dotnet tool install -g dotnet-releaser --configfile .github/workflows/nuget_org_only.config
         dotnet-releaser run --nuget-token "${{secrets.NUGET_TOKEN}}" --github-token "${{secrets.GITHUB_TOKEN}}" src/dotnet-releaser.toml

.github/workflows/nuget_org_only.config

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+  <packageSources>
+    <clear />
+    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
+  </packageSources>
+</configuration>

readme.md

@@ -12,7 +12,7 @@ You can **try Markdig online** and compare it to other implementations on [babel
 
 - **Very fast parser and html renderer** (no-regexp), very lightweight in terms of GC pressure. See benchmarks
 - **Abstract Syntax Tree** with precise source code location for syntax tree, useful when building a Markdown editor.
-  - Checkout [MarkdownEditor for Visual Studio](https://visualstudiogallery.msdn.microsoft.com/eaab33c3-437b-4918-8354-872dfe5d1bfe) powered by Markdig!
+  - Checkout [Markdown Editor v2 for Visual Studio 2022](https://marketplace.visualstudio.com/items?itemName=MadsKristensen.MarkdownEditor2) powered by Markdig!
 - Converter to **HTML**
 - Passing more than **600+ tests** from the latest [CommonMark specs (0.30)](http://spec.commonmark.org/)
 - Includes all the core elements of CommonMark:

src/Markdig.Benchmarks/Markdig.Benchmarks.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <OutputType>Exe</OutputType>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <IsPackable>false</IsPackable>
@@ -19,12 +19,12 @@
     </Content>
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="BenchmarkDotNet" Version="0.13.1" />
-    <PackageReference Include="BenchmarkDotNet.Diagnostics.Windows" Version="0.13.1" />
+    <PackageReference Include="BenchmarkDotNet" Version="0.13.12" />
+    <PackageReference Include="BenchmarkDotNet.Diagnostics.Windows" Version="0.13.12" />
     <PackageReference Include="CommonMark.NET" Version="0.15.1" />
     <PackageReference Include="Markdown" Version="2.2.1" />
     <PackageReference Include="MarkdownSharp" Version="2.0.5" />
-    <PackageReference Include="Microsoft.Diagnostics.Runtime" Version="2.0.226801" />
+    <PackageReference Include="Microsoft.Diagnostics.Runtime" Version="3.1.506101" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Markdig\Markdig.csproj" />

src/Markdig.Tests/GlobalUsings.cs

@@ -0,0 +1,5 @@
+// Copyright (c) Alexandre Mutel. All rights reserved.
+// This file is licensed under the BSD-Clause 2 license.
+// See the license.txt file in the project root for more information.
+
+global using Assert = NUnit.Framework.Legacy.ClassicAssert;

src/Markdig.Tests/Markdig.Tests.csproj

@@ -1,19 +1,19 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <OutputType>Exe</OutputType>
     <IsPackable>false</IsPackable>
     <ImplicitUsings>enable</ImplicitUsings>
     <StartupObject>Markdig.Tests.Program</StartupObject>
-    <SpecExecutable>$(MSBuildProjectDirectory)\..\SpecFileGen\bin\$(Configuration)\net6.0\SpecFileGen.dll</SpecExecutable>
-    <SpecTimestamp>$(MSBuildProjectDirectory)\..\SpecFileGen\bin\$(Configuration)\net6.0\SpecFileGen.timestamp</SpecTimestamp>
+    <SpecExecutable>$(MSBuildProjectDirectory)\..\SpecFileGen\bin\$(Configuration)\net8.0\SpecFileGen.dll</SpecExecutable>
+    <SpecTimestamp>$(MSBuildProjectDirectory)\..\SpecFileGen\bin\$(Configuration)\net8.0\SpecFileGen.timestamp</SpecTimestamp>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.1.0" />
-    <PackageReference Include="NUnit" Version="3.13.3" />
-    <PackageReference Include="NUnit3TestAdapter" Version="4.2.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
+    <PackageReference Include="NUnit" Version="4.0.1" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.5.0" />
   </ItemGroup>
 
   <ItemGroup>

src/Markdig.Tests/MiscTests.cs

@@ -1,7 +1,8 @@
 using System.Text.RegularExpressions;
 
 using Markdig.Extensions.AutoLinks;
-
+using Markdig.Extensions.Tables;
+using Markdig.Syntax;
 using NUnit.Framework;
 
 namespace Markdig.Tests;
@@ -198,9 +199,9 @@ $$
 <div class=""math"">
 \begin{align}
 \sqrt{37} & = \sqrt{\frac{73^2-1}{12^2}} \\
- & = \sqrt{\frac{73^2}{12^2}\cdot\frac{73^2-1}{73^2}} \\ 
+ & = \sqrt{\frac{73^2}{12^2}\cdot\frac{73^2-1}{73^2}} \\
  & = \sqrt{\frac{73^2}{12^2}}\sqrt{\frac{73^2-1}{73^2}} \\
- & = \frac{73}{12}\sqrt{1 - \frac{1}{73^2}} \\ 
+ & = \frac{73}{12}\sqrt{1 - \frac{1}{73^2}} \\
  & \approx \frac{73}{12}\left(1 - \frac{1}{2\cdot73^2}\right)
 \end{align}
 </div>
@@ -291,4 +292,29 @@ $$
         TestParser.TestSpec("www.foo.bar", "<p><a href=\"http://www.foo.bar\">www.foo.bar</a></p>", pipeline);
         TestParser.TestSpec("www.foo.bar", "<p><a href=\"https://www.foo.bar\">www.foo.bar</a></p>", httpsPipeline);
     }
+
+    [Test]
+    public void RootInlineHasCorrectSourceSpan()
+    {
+        var pipeline = new MarkdownPipelineBuilder().UsePreciseSourceLocation().Build();
+        pipeline.TrackTrivia = true;
+
+        var document = Markdown.Parse("0123456789\n", pipeline);
+
+        var expectedSourceSpan = new SourceSpan(0, 10);
+        Assert.That(((LeafBlock)document.LastChild).Inline.Span == expectedSourceSpan);
+    }
+
+    [Test]
+    public void RootInlineInTableCellHasCorrectSourceSpan()
+    {
+        var pipeline = new MarkdownPipelineBuilder().UsePreciseSourceLocation().UseAdvancedExtensions().Build();
+        pipeline.TrackTrivia = true;
+
+        var document = Markdown.Parse("| a | b |\n| --- | --- |\n| <span id=\"dest\"></span><span id=\"DEST\"></span>*dest*<br/> | \\[in\\] The address of the result of the operation.<br/> |", pipeline);
+
+        var paragraph = (ParagraphBlock)((TableCell)((TableRow)((Table)document.LastChild).LastChild).First()).LastChild;
+        Assert.That(paragraph.Inline.Span.Start == paragraph.Inline.FirstChild.Span.Start);
+        Assert.That(paragraph.Inline.Span.End == paragraph.Inline.LastChild.Span.End);
+    }
 }

src/Markdig.Tests/TestEmphasisPlus.cs

@@ -1,7 +1,10 @@
 // Copyright (c) Alexandre Mutel. All rights reserved.
-// This file is licensed under the BSD-Clause 2 license. 
+// This file is licensed under the BSD-Clause 2 license.
 // See the license.txt file in the project root for more information.
 
+using Markdig.Syntax;
+using Markdig.Syntax.Inlines;
+
 namespace Markdig.Tests;
 
 [TestFixture]
@@ -18,4 +21,17 @@ public partial class TestEmphasisPlus
     {
         TestParser.TestSpec("normal ***Strong emphasis*** normal", "<p>normal <em><strong>Strong emphasis</strong></em> normal</p>", "");
     }
+
+    [Test]
+    public void OpenEmphasisHasConvenientContentStringSlice()
+    {
+        var pipeline = new MarkdownPipelineBuilder().Build();
+
+        var document = Markdown.Parse("test*test", pipeline);
+
+        var emphasisDelimiterLiteral = (LiteralInline)((ParagraphBlock)document.LastChild).Inline.ElementAt(1);
+        Assert.That(emphasisDelimiterLiteral.Content.Text == "test*test");
+        Assert.That(emphasisDelimiterLiteral.Content.Start == 4);
+        Assert.That(emphasisDelimiterLiteral.Content.End == 4);
+    }
 }

src/Markdig.Tests/TestNormalize.cs

@@ -51,6 +51,16 @@ public class TestNormalize
         });
     }
 
+    [Test]
+    public void SyntaxHeadlineLevel7()
+    {
+        AssertSyntax("####### Headline", new HeadingBlock(null) {
+            HeaderChar = '#',
+            Level = 7,
+            Inline = new ContainerInline().AppendChild(new LiteralInline("Headline")),
+        });
+    }
+
     [Test]
     public void SyntaxParagraph()
     {

src/Markdig.Tests/TestSourcePosition.cs

@@ -67,6 +67,60 @@ literal      ( 2, 0) 12-21
 ");
     }
 
+    [Test]
+    public void TestParagraphWithEndNewLine()
+    {
+        Check("0123456789\n", @"
+paragraph    ( 0, 0)  0-10
+literal      ( 0, 0)  0-9
+linebreak    ( 0,10) 10-10
+", trackTrivia: true);
+
+        Check("0123456789\r", @"
+paragraph    ( 0, 0)  0-10
+literal      ( 0, 0)  0-9
+linebreak    ( 0,10) 10-10
+", trackTrivia: true);
+
+        Check("0123456789\r\n", @"
+paragraph    ( 0, 0)  0-11
+literal      ( 0, 0)  0-9
+linebreak    ( 0,10) 10-11
+", trackTrivia: true);
+    }
+
+
+    [Test]
+    public void TestMultipleParagraphsWithEndNewLine()
+    {
+        Check("0123456789\n\n0123456789\n\n", @"
+paragraph    ( 0, 0)  0-10
+literal      ( 0, 0)  0-9
+linebreak    ( 0,10) 10-10
+paragraph    ( 2, 0) 12-22
+literal      ( 2, 0) 12-21
+linebreak    ( 2,10) 22-22
+", trackTrivia: true);
+
+        Check("0123456789\r\r0123456789\r\r", @"
+paragraph    ( 0, 0)  0-10
+literal      ( 0, 0)  0-9
+linebreak    ( 0,10) 10-10
+paragraph    ( 2, 0) 12-22
+literal      ( 2, 0) 12-21
+linebreak    ( 2,10) 22-22
+", trackTrivia: true);
+
+        Check("0123456789\r\n\r\n0123456789\r\n\r\n", @"
+paragraph    ( 0, 0)  0-11
+literal      ( 0, 0)  0-9
+linebreak    ( 0,10) 10-11
+paragraph    ( 2, 0) 14-25
+literal      ( 2, 0) 14-23
+linebreak    ( 2,10) 24-25
+", trackTrivia: true);
+    }
+
     [Test]
     public void TestEmphasis()
     {
@@ -825,9 +879,10 @@ literal      ( 8, 2) 77-92
 ");
     }
 
-    private static void Check(string text, string expectedResult, string extensions = null)
+    private static void Check(string text, string expectedResult, string extensions = null, bool trackTrivia = false)
     {
         var pipelineBuilder = new MarkdownPipelineBuilder().UsePreciseSourceLocation();
+        pipelineBuilder.TrackTrivia = trackTrivia;
         if (extensions != null)
         {
             pipelineBuilder.Configure(extensions);

src/Markdig.Tests/TestStringSliceList.cs

@@ -1,3 +1,4 @@
+using System.Collections;
 using System.Text;
 
 using Markdig.Helpers;
@@ -215,4 +216,27 @@ public class TestStringSliceList
         TextAssert.AreEqual("ABC\r\nD\r\n", chars.ToString());
         TextAssert.AreEqual("ABC\r\nD", text.ToString());
     }
-}
+
+    [Test]
+    public void TestStringLineGroup_EnumeratorReturnsRealLines()
+    {
+        string str = "A\r\n";
+        var text = new StringLineGroup(4)
+        {
+            new StringSlice(str, NewLine.CarriageReturnLineFeed) { Start = 0, End = 0 }
+        };
+
+        var enumerator = ((IEnumerable)text).GetEnumerator();
+        Assert.True(enumerator.MoveNext());
+        StringLine currentLine = (StringLine)enumerator.Current;
+        TextAssert.AreEqual("A", currentLine.ToString());
+        Assert.False(enumerator.MoveNext());
+        
+        var nonBoxedEnumerator = text.GetEnumerator();
+
+        Assert.True(nonBoxedEnumerator.MoveNext());
+        currentLine = (StringLine)nonBoxedEnumerator.Current;
+        TextAssert.AreEqual("A", currentLine.ToString());
+        Assert.False(nonBoxedEnumerator.MoveNext());
+    }
+}

src/Markdig.Tests/TestYamlFrontMatterExtension.cs

@@ -75,8 +75,11 @@ public class TestYamlFrontMatterExtension
             ObjectRenderers = new ObjectRendererCollection();
         }
 
+#pragma warning disable CS0067 // ObjectWriteBefore/ObjectWriteAfter is never used
         public event Action<IMarkdownRenderer, MarkdownObject> ObjectWriteBefore;
         public event Action<IMarkdownRenderer, MarkdownObject> ObjectWriteAfter;
+#pragma warning restore CS0067
+
         public ObjectRendererCollection ObjectRenderers { get; }
         public object Render(MarkdownObject markdownObject)
         {

src/Markdig.WebApp/Markdig.WebApp.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <PreserveCompilationContext>true</PreserveCompilationContext>
     <AssemblyName>Markdig.WebApp</AssemblyName>
     <ImplicitUsings>enable</ImplicitUsings>
@@ -14,7 +14,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.ApplicationInsights.AspNetCore" Version="2.20.0" />
+    <PackageReference Include="Microsoft.ApplicationInsights.AspNetCore" Version="2.22.0" />
   </ItemGroup>
 
   <ItemGroup>

src/Markdig/Extensions/Abbreviations/AbbreviationParser.cs

@@ -20,7 +20,7 @@ public class AbbreviationParser : BlockParser
     /// </summary>
     public AbbreviationParser()
     {
-        OpeningCharacters = new[] { '*' };
+        OpeningCharacters = ['*'];
     }
 
     public override BlockState TryOpen(BlockProcessor processor)

src/Markdig/Extensions/AutoIdentifiers/AutoIdentifierExtension.cs

@@ -2,8 +2,6 @@
 // This file is licensed under the BSD-Clause 2 license.
 // See the license.txt file in the project root for more information.
 
-using System.IO;
-
 using Markdig.Helpers;
 using Markdig.Parsers;
 using Markdig.Renderers;
@@ -20,8 +18,10 @@ namespace Markdig.Extensions.AutoIdentifiers;
 public class AutoIdentifierExtension : IMarkdownExtension
 {
     private const string AutoIdentifierKey = "AutoIdentifier";
-    private readonly AutoIdentifierOptions options;
-    private readonly StripRendererCache rendererCache = new StripRendererCache();
+
+    private static readonly StripRendererCache _rendererCache = new();
+
+    private readonly AutoIdentifierOptions _options;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="AutoIdentifierExtension"/> class.
@@ -29,7 +29,7 @@ public class AutoIdentifierExtension : IMarkdownExtension
     /// <param name="options">The options.</param>
     public AutoIdentifierExtension(AutoIdentifierOptions options)
     {
-        this.options = options;
+        _options = options;
     }
 
     public void Setup(MarkdownPipelineBuilder pipeline)
@@ -68,7 +68,7 @@ public class AutoIdentifierExtension : IMarkdownExtension
         }
 
         // If the AutoLink options is set, we register a LinkReferenceDefinition at the document level
-        if ((options & AutoIdentifierOptions.AutoLink) != 0)
+        if ((_options & AutoIdentifierOptions.AutoLink) != 0)
         {
             var headingLine = headingBlock.Lines.Lines[0];
 
@@ -157,16 +157,17 @@ public class AutoIdentifierExtension : IMarkdownExtension
         }
 
         // Use internally a HtmlRenderer to strip links from a heading
-        var stripRenderer = rendererCache.Get();
+        var stripRenderer = _rendererCache.Get();
 
         stripRenderer.Render(headingBlock.Inline);
-        var headingText = stripRenderer.Writer.ToString()!;
-        rendererCache.Release(stripRenderer);
+        ReadOnlySpan<char> rawHeadingText = ((FastStringWriter)stripRenderer.Writer).AsSpan();
 
         // Urilize the link
-        headingText = (options & AutoIdentifierOptions.GitHub) != 0
-            ? LinkHelper.UrilizeAsGfm(headingText)
-            : LinkHelper.Urilize(headingText, (options & AutoIdentifierOptions.AllowOnlyAscii) != 0);
+        string headingText = (_options & AutoIdentifierOptions.GitHub) != 0
+            ? LinkHelper.UrilizeAsGfm(rawHeadingText)
+            : LinkHelper.Urilize(rawHeadingText, (_options & AutoIdentifierOptions.AllowOnlyAscii) != 0);
+
+        _rendererCache.Release(stripRenderer);
 
         // If the heading is empty, use the word "section" instead
         var baseHeadingId = string.IsNullOrEmpty(headingText) ? "section" : headingText;
@@ -197,7 +198,7 @@ public class AutoIdentifierExtension : IMarkdownExtension
     {
         protected override HtmlRenderer NewInstance()
         {
-            var headingWriter = new StringWriter();
+            var headingWriter = new FastStringWriter();
             var stripRenderer = new HtmlRenderer(headingWriter)
             {
                 // Set to false both to avoid having any HTML tags in the output
@@ -209,7 +210,9 @@ public class AutoIdentifierExtension : IMarkdownExtension
 
         protected override void Reset(HtmlRenderer instance)
         {
-            instance.Reset();
+            instance.ResetInternal();
+
+            ((FastStringWriter)instance.Writer).Reset();
         }
     }
 }

src/Markdig/Extensions/AutoLinks/AutoLinkExtension.cs

@@ -11,14 +11,9 @@ namespace Markdig.Extensions.AutoLinks;
 /// Extension to automatically create <see cref="LinkInline"/> when a link url http: or mailto: is found.
 /// </summary>
 /// <seealso cref="IMarkdownExtension" />
-public class AutoLinkExtension : IMarkdownExtension
+public class AutoLinkExtension(AutoLinkOptions? options) : IMarkdownExtension
 {
-    public readonly AutoLinkOptions Options;
-
-    public AutoLinkExtension(AutoLinkOptions? options)
-    {
-        Options = options ?? new AutoLinkOptions();
-    }
+    public readonly AutoLinkOptions Options = options ?? new AutoLinkOptions();
 
     public void Setup(MarkdownPipelineBuilder pipeline)
     {

src/Markdig/Extensions/AutoLinks/AutoLinkParser.cs

@@ -22,14 +22,14 @@ public class AutoLinkParser : InlineParser
     {
         Options = options ?? throw new ArgumentNullException(nameof(options));
 
-        OpeningCharacters = new char[]
-        {
+        OpeningCharacters =
+        [
             'h', // for http:// and https://
             'f', // for ftp://
             'm', // for mailto:
             't', // for tel:
             'w', // for www.
-        };
+        ];
 
         _listOfCharCache = new ListOfCharCache();
     }

src/Markdig/Extensions/CustomContainers/CustomContainerParser.cs

@@ -17,7 +17,7 @@ public class CustomContainerParser : FencedBlockParserBase<CustomContainer>
     /// </summary>
     public CustomContainerParser()
     {
-        OpeningCharacters = new [] {':'};
+        OpeningCharacters = [':'];
 
         // We don't need a prefix
         InfoPrefix = null;

src/Markdig/Extensions/DefinitionLists/DefinitionListParser.cs

@@ -18,7 +18,7 @@ public class DefinitionListParser : BlockParser
     /// </summary>
     public DefinitionListParser()
     {
-        OpeningCharacters = new [] {':', '~'};
+        OpeningCharacters = [':', '~'];
     }
 
     public override BlockState TryOpen(BlockProcessor processor)

src/Markdig/Extensions/Emoji/EmojiMapping.cs

@@ -1786,6 +1786,6 @@ public class EmojiMapping
                 ThrowHelper.ArgumentException(string.Format("Smiley {0} is already present in the emoji mapping", smiley.Key));
         }
 
-        OpeningCharacters = new List<char>(firstChars).ToArray();
+        OpeningCharacters = [.. firstChars];
     }
 }

src/Markdig/Extensions/Figures/FigureBlockParser.cs

@@ -18,7 +18,7 @@ public class FigureBlockParser : BlockParser
     /// </summary>
     public FigureBlockParser()
     {
-        OpeningCharacters = new[] { '^' };
+        OpeningCharacters = ['^'];
     }
 
     public override BlockState TryOpen(BlockProcessor processor)

src/Markdig/Extensions/Footers/FooterBlockParser.cs

@@ -19,7 +19,7 @@ public class FooterBlockParser : BlockParser
     /// </summary>
     public FooterBlockParser()
     {
-        OpeningCharacters = new[] {'^'};
+        OpeningCharacters = ['^'];
     }
 
     public override BlockState TryOpen(BlockProcessor processor)

src/Markdig/Extensions/Footnotes/FootnoteParser.cs

@@ -22,7 +22,7 @@ public class FootnoteParser : BlockParser
 
     public FootnoteParser()
     {
-        OpeningCharacters = new [] {'['};
+        OpeningCharacters = ['['];
     }
 
     public override BlockState TryOpen(BlockProcessor processor)
@@ -49,7 +49,7 @@ public class FootnoteParser : BlockParser
 
         // Advance the column
         int deltaColumn = processor.Start - start;
-        processor.Column = processor.Column + deltaColumn;
+        processor.Column += deltaColumn;
 
         processor.NextChar(); // Skip ':'
 
@@ -170,10 +170,8 @@ public class FootnoteParser : BlockParser
                 paragraphBlock = new ParagraphBlock();
                 footnote.Add(paragraphBlock);
             }
-            if (paragraphBlock.Inline == null)
-            {
-                paragraphBlock.Inline = new ContainerInline();
-            }
+
+            paragraphBlock.Inline ??= new ContainerInline();
 
             foreach (var link in footnote.Links)
             {

src/Markdig/Extensions/GenericAttributes/GenericAttributesParser.cs

@@ -23,7 +23,7 @@ public class GenericAttributesParser : InlineParser
     /// </summary>
     public GenericAttributesParser()
     {
-        OpeningCharacters = new[] { '{' };
+        OpeningCharacters = ['{'];
     }
 
     public override bool Match(InlineProcessor processor, ref StringSlice slice)
@@ -136,10 +136,7 @@ public class GenericAttributesParser : InlineParser
                 var text = slice.Text.Substring(start, end - start + 1);
                 if (isClass)
                 {
-                    if (classes is null)
-                    {
-                        classes = new List<string>();
-                    }
+                    classes ??= new List<string>();
                     classes.Add(text);
                 }
                 else

src/Markdig/Extensions/Mathematics/MathBlockParser.cs

@@ -20,7 +20,7 @@ public class MathBlockParser : FencedBlockParserBase<MathBlock>
     /// </summary>
     public MathBlockParser()
     {
-        OpeningCharacters = new [] {'$'};
+        OpeningCharacters = ['$'];
         // We expect to match only a $$, no less, no more
         MinimumMatchCount = 2;
         MaximumMatchCount = 2;

src/Markdig/Extensions/Mathematics/MathInlineParser.cs

@@ -21,7 +21,7 @@ public class MathInlineParser : InlineParser
     /// </summary>
     public MathInlineParser()
     {
-        OpeningCharacters = new[] { '$' };
+        OpeningCharacters = ['$'];
         DefaultClass = "math";
     }
 

src/Markdig/Extensions/MediaLinks/HostProviderBuilder.cs

@@ -11,23 +11,19 @@ namespace Markdig.Extensions.MediaLinks;
 
 public class HostProviderBuilder
 {
-    private sealed class DelegateProvider : IHostProvider
+    private sealed class DelegateProvider(
+        string hostPrefix,
+        Func<Uri, string?> handler,
+        bool allowFullscreen = true,
+        string? className = null) : IHostProvider
     {
-        public DelegateProvider(string hostPrefix, Func<Uri, string?> handler, bool allowFullscreen = true, string? className = null)
-        {
-            HostPrefix = hostPrefix;
-            Delegate = handler;
-            AllowFullScreen = allowFullscreen;
-            Class = className;
-        }
+        public string HostPrefix { get; } = hostPrefix;
 
-        public string HostPrefix { get; }
+        public Func<Uri, string?> Delegate { get; } = handler;
 
-        public Func<Uri, string?> Delegate { get; }
+        public bool AllowFullScreen { get; } = allowFullscreen;
 
-        public bool AllowFullScreen { get; }
-
-        public string? Class { get; }
+        public string? Class { get; } = className;
 
         public bool TryHandle(Uri mediaUri, bool isSchemaRelative, [NotNullWhen(true)] out string? iframeUrl)
         {
@@ -71,7 +67,7 @@ public class HostProviderBuilder
 
     #region Known providers
 
-    private static readonly string[] SplitAnd = { "&" };
+    private static readonly string[] SplitAnd = ["&"];
     private static string[] SplitQuery(Uri uri)
     {
         var query = uri.Query.Substring(uri.Query.IndexOf('?') + 1);

src/Markdig/Extensions/NoRefLinks/NoFollowLinksExtension.cs

@@ -17,7 +17,7 @@ public class NoFollowLinksExtension : IMarkdownExtension
 
     public NoFollowLinksExtension()
     {
-        _referralLinksExtension = new ReferralLinksExtension(new[] { "nofollow" });
+        _referralLinksExtension = new ReferralLinksExtension(["nofollow"]);
     }
 
     public void Setup(MarkdownPipelineBuilder pipeline)

src/Markdig/Extensions/SmartyPants/SmartyPantsInlineParser.cs

@@ -19,7 +19,7 @@ public class SmartyPantsInlineParser : InlineParser, IPostInlineProcessor
     /// </summary>
     public SmartyPantsInlineParser()
     {
-        OpeningCharacters = new[] {'\'', '"', '<', '>', '.', '-'};
+        OpeningCharacters = ['\'', '"', '<', '>', '.', '-'];
     }
 
     public override bool Match(InlineProcessor processor, ref StringSlice slice)

src/Markdig/Extensions/Tables/GridTableParser.cs

@@ -12,7 +12,7 @@ public class GridTableParser : BlockParser
 {
     public GridTableParser()
     {
-        OpeningCharacters = new[] { '+' };
+        OpeningCharacters = ['+'];
     }
 
     public override BlockState TryOpen(BlockProcessor processor)
@@ -144,7 +144,7 @@ public class GridTableParser : BlockParser
                 line.Start = lineStart + columnSlice.Start + 1;
                 line.End = lineStart + columnSlice.End - 1;
                 line.Trim();
-                if (line.IsEmptyOrWhitespace() || !IsRowSeperator(line))
+                if (line.IsEmptyOrWhitespace() || !IsRowSeparator(line))
                 {
                     hasRowSpan = true;
                     columnSlice.CurrentCell.RowSpan++;
@@ -158,7 +158,7 @@ public class GridTableParser : BlockParser
         }
     }
 
-    private static bool IsRowSeperator(StringSlice slice)
+    private static bool IsRowSeparator(StringSlice slice)
     {
         char c = slice.CurrentChar;
         do
@@ -263,7 +263,7 @@ public class GridTableParser : BlockParser
             }
             sliceForCell.TrimEnd();
 
-            if (!isRowLine || !IsRowSeperator(sliceForCell))
+            if (!isRowLine || !IsRowSeparator(sliceForCell))
             {
                 if (columnSlice.CurrentCell is null)
                 {
@@ -273,10 +273,7 @@ public class GridTableParser : BlockParser
                         ColumnIndex = i
                     };
 
-                    if (columnSlice.BlockProcessor is null)
-                    {
-                        columnSlice.BlockProcessor = processor.CreateChild();
-                    }
+                    columnSlice.BlockProcessor ??= processor.CreateChild();
 
                     // Ensure that the BlockParser is aware that the TableCell is the top-level container
                     columnSlice.BlockProcessor.Open(columnSlice.CurrentCell);

src/Markdig/Extensions/Tables/GridTableState.cs

@@ -10,21 +10,15 @@ namespace Markdig.Extensions.Tables;
 /// <summary>
 /// Internal state used by the <see cref="GridTableParser"/>
 /// </summary>
-internal sealed class GridTableState
+internal sealed class GridTableState(int start, bool expectRow)
 {
-    public GridTableState(int start, bool expectRow)
-    {
-        Start = start;
-        ExpectRow = expectRow;
-    }
-
-    public int Start { get; }
+    public int Start { get; } = start;
 
     public StringLineGroup Lines;
 
     public List<ColumnSlice>? ColumnSlices { get; private set; }
 
-    public bool ExpectRow { get; }
+    public bool ExpectRow { get; } = expectRow;
 
     public int StartRowGroup { get; set; }
 
@@ -45,26 +39,18 @@ internal sealed class GridTableState
         ColumnSlices.Add(new ColumnSlice(start, end, align));
     }
 
-    public sealed class ColumnSlice
+    public sealed class ColumnSlice(int start, int end, TableColumnAlign? align)
     {
-        public ColumnSlice(int start, int end, TableColumnAlign? align)
-        {
-            Start = start;
-            End = end;
-            Align = align;
-            CurrentColumnSpan = -1;
-        }
-
         /// <summary>
         /// Gets or sets the index position of this column (after the |)
         /// </summary>
-        public int Start { get; }
+        public int Start { get; } = start;
 
-        public int End { get; }
+        public int End { get; } = end;
 
-        public TableColumnAlign? Align { get; }
+        public TableColumnAlign? Align { get; } = align;
 
-        public int CurrentColumnSpan { get; set; }
+        public int CurrentColumnSpan { get; set; } = -1;
 
         public int PreviousColumnSpan { get; set; }
 

src/Markdig/Extensions/Tables/PipeTableBlockParser.cs

@@ -22,7 +22,7 @@ public class PipeTableBlockParser : BlockParser
     /// </summary>
     public PipeTableBlockParser()
     {
-        OpeningCharacters = new[] {'-'};
+        OpeningCharacters = ['-'];
     }
 
     public override BlockState TryOpen(BlockProcessor processor)

src/Markdig/Extensions/Tables/PipeTableParser.cs

@@ -25,12 +25,12 @@ public class PipeTableParser : InlineParser, IPostInlineProcessor
     /// <summary>
     /// Initializes a new instance of the <see cref="PipeTableParser" /> class.
     /// </summary>
-    /// <param name="lineBreakParser">The linebreak parser to use</param>
+    /// <param name="lineBreakParser">The line break parser to use</param>
     /// <param name="options">The options.</param>
     public PipeTableParser(LineBreakInlineParser lineBreakParser, PipeTableOptions? options = null)
     {
         this.lineBreakParser = lineBreakParser ?? throw new ArgumentNullException(nameof(lineBreakParser));
-        OpeningCharacters = new[] { '|', '\n', '\r' };
+        OpeningCharacters = ['|', '\n', '\r'];
         Options = options ?? new PipeTableOptions();
     }
 
@@ -443,6 +443,11 @@ public class PipeTableParser : InlineParser, IPostInlineProcessor
         {
             var paragraph = (ParagraphBlock) cell[0];
             state.PostProcessInlines(postInlineProcessorIndex + 1, paragraph.Inline, null, true);
+            if (paragraph.Inline?.LastChild is not null)
+            {
+                paragraph.Inline.Span.End = paragraph.Inline.LastChild.Span.End;
+                paragraph.UpdateSpanEnd(paragraph.Inline.LastChild.Span.End);
+            }
         }
 
         // Clear cells when we are done
@@ -520,7 +525,7 @@ public class PipeTableParser : InlineParser, IPostInlineProcessor
                 // Create aligns until we may have a header row
 
                 aligns ??= new List<TableColumnDefinition>();
-                
+
                 aligns.Add(new TableColumnDefinition() { Alignment =  align });
 
                 // If this is the last delimiter, we need to check the right side of the `|` delimiter
@@ -632,10 +637,10 @@ public class PipeTableParser : InlineParser, IPostInlineProcessor
 
         public int LineIndex { get; set; }
 
-        public List<Inline> ColumnAndLineDelimiters { get; } = new();
+        public List<Inline> ColumnAndLineDelimiters { get; } = [];
 
-        public List<TableCell> Cells { get; } = new();
+        public List<TableCell> Cells { get; } = [];
 
-        public List<Inline> EndOfLines { get; } = new();
+        public List<Inline> EndOfLines { get; } = [];
     }
 }

src/Markdig/Extensions/TaskLists/TaskListInlineParser.cs

@@ -19,7 +19,7 @@ public class TaskListInlineParser : InlineParser
     /// </summary>
     public TaskListInlineParser()
     {
-        OpeningCharacters = new[] {'['};
+        OpeningCharacters = ['['];
         ListClass = "contains-task-list";
         ListItemClass = "task-list-item";
     }

src/Markdig/Extensions/Yaml/YamlFrontMatterParser.cs

@@ -26,7 +26,7 @@ public class YamlFrontMatterParser : BlockParser
     /// </summary>
     public YamlFrontMatterParser()
     {
-        this.OpeningCharacters = new[] { '-' };
+        OpeningCharacters = ['-'];
     }
 
     /// <summary>

src/Markdig/Helpers/BlockWrapper.cs

@@ -7,14 +7,9 @@ using Markdig.Syntax;
 namespace Markdig.Helpers;
 
 // Used to avoid the overhead of type covariance checks
-internal readonly struct BlockWrapper : IEquatable<BlockWrapper>
+internal readonly struct BlockWrapper(Block block) : IEquatable<BlockWrapper>
 {
-    public readonly Block Block;
-
-    public BlockWrapper(Block block)
-    {
-        Block = block;
-    }
+    public readonly Block Block = block;
 
     public static implicit operator Block(BlockWrapper wrapper) => wrapper.Block;
 
@@ -22,7 +17,7 @@ internal readonly struct BlockWrapper : IEquatable<BlockWrapper>
 
     public bool Equals(BlockWrapper other) => ReferenceEquals(Block, other.Block);
 
-    public override bool Equals(object obj) => Block.Equals(obj);
+    public override bool Equals(object? obj) => Block.Equals(obj);
 
     public override int GetHashCode() => Block.GetHashCode();
 }

src/Markdig/Helpers/CharHelper.cs

@@ -30,15 +30,17 @@ public static class CharHelper
         { 'I', 1 }, { 'V', 5 }, { 'X', 10 }
     };
 
-    private static readonly char[] punctuationExceptions = { '−', '-', '†', '‡' };
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private static bool IsPunctuationException(char c) =>
+        c is '−' or '-' or '†' or '‡';
 
     public static void CheckOpenCloseDelimiter(char pc, char c, bool enableWithinWord, out bool canOpen, out bool canClose)
     {
         pc.CheckUnicodeCategory(out bool prevIsWhiteSpace, out bool prevIsPunctuation);
         c.CheckUnicodeCategory(out bool nextIsWhiteSpace, out bool nextIsPunctuation);
 
-        var prevIsExcepted = prevIsPunctuation && punctuationExceptions.Contains(pc);
-        var nextIsExcepted = nextIsPunctuation && punctuationExceptions.Contains(c);
+        var prevIsExcepted = prevIsPunctuation && IsPunctuationException(pc);
+        var nextIsExcepted = nextIsPunctuation && IsPunctuationException(c);
 
         // A left-flanking delimiter run is a delimiter run that is
         // (1) not followed by Unicode whitespace, and either
@@ -126,19 +128,6 @@ public static class CharHelper
         return (column & (TabSize - 1)) != 0;
     }
 
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public static bool Contains(this char[] charList, char c)
-    {
-        foreach (char ch in charList)
-        {
-            if (ch == c)
-            {
-                return true;
-            }
-        }
-        return false;
-    }
-
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static bool IsWhitespace(this char c)
     {
@@ -178,7 +167,7 @@ public static class CharHelper
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static bool IsControl(this char c)
     {
-        return c < ' ' || char.IsControl(c);
+        return char.IsControl(c);
     }
 
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
@@ -211,15 +200,17 @@ public static class CharHelper
         {
             // A Unicode punctuation character is an ASCII punctuation character
             // or anything in the general Unicode categories Pc, Pd, Pe, Pf, Pi, Po, or Ps.
+            const int PunctuationCategoryMask =
+                1 << (int)UnicodeCategory.ConnectorPunctuation |
+                1 << (int)UnicodeCategory.DashPunctuation |
+                1 << (int)UnicodeCategory.OpenPunctuation |
+                1 << (int)UnicodeCategory.ClosePunctuation |
+                1 << (int)UnicodeCategory.InitialQuotePunctuation |
+                1 << (int)UnicodeCategory.FinalQuotePunctuation |
+                1 << (int)UnicodeCategory.OtherPunctuation;
+
             space = false;
-            UnicodeCategory category = CharUnicodeInfo.GetUnicodeCategory(c);
-            punctuation = category == UnicodeCategory.ConnectorPunctuation
-                || category == UnicodeCategory.DashPunctuation
-                || category == UnicodeCategory.OpenPunctuation
-                || category == UnicodeCategory.ClosePunctuation
-                || category == UnicodeCategory.InitialQuotePunctuation
-                || category == UnicodeCategory.FinalQuotePunctuation
-                || category == UnicodeCategory.OtherPunctuation;
+            punctuation = (PunctuationCategoryMask & (1 << (int)CharUnicodeInfo.GetUnicodeCategory(c))) != 0;
         }
     }
 
@@ -236,14 +227,16 @@ public static class CharHelper
         }
         else
         {
-            var category = CharUnicodeInfo.GetUnicodeCategory(c);
-            return category == UnicodeCategory.ConnectorPunctuation
-                || category == UnicodeCategory.DashPunctuation
-                || category == UnicodeCategory.OpenPunctuation
-                || category == UnicodeCategory.ClosePunctuation
-                || category == UnicodeCategory.InitialQuotePunctuation
-                || category == UnicodeCategory.FinalQuotePunctuation
-                || category == UnicodeCategory.OtherPunctuation;
+            const int PunctuationCategoryMask =
+                1 << (int)UnicodeCategory.ConnectorPunctuation |
+                1 << (int)UnicodeCategory.DashPunctuation |
+                1 << (int)UnicodeCategory.OpenPunctuation |
+                1 << (int)UnicodeCategory.ClosePunctuation |
+                1 << (int)UnicodeCategory.InitialQuotePunctuation |
+                1 << (int)UnicodeCategory.FinalQuotePunctuation |
+                1 << (int)UnicodeCategory.OtherPunctuation;
+
+            return (PunctuationCategoryMask & (1 << (int)CharUnicodeInfo.GetUnicodeCategory(c))) != 0;
         }
     }
 
@@ -729,11 +722,11 @@ public static class CharHelper
     }
 
     // Used by ListExtraItemParser to format numbers from 1 - 26
-    private static readonly string[] smallNumberStringCache = {
+    private static readonly string[] smallNumberStringCache = [
         "0", "1", "2", "3", "4", "5", "6", "7", "8", "9",
         "10", "11", "12", "13", "14", "15", "16", "17", "18", "19",
         "20", "21", "22", "23", "24", "25", "26",
-    };
+    ];
 
     internal static string SmallNumberToString(int number)
     {

src/Markdig/Helpers/CharacterMap.cs

@@ -2,14 +2,10 @@
 // This file is licensed under the BSD-Clause 2 license. 
 // See the license.txt file in the project root for more information.
 
+using System.Buffers;
 using System.Diagnostics;
 using System.Linq;
 using System.Runtime.CompilerServices;
-#if NETCOREAPP3_1_OR_GREATER
-using System.Numerics;
-using System.Runtime.Intrinsics;
-using System.Runtime.Intrinsics.X86;
-#endif
 
 namespace Markdig.Helpers;
 
@@ -19,13 +15,9 @@ namespace Markdig.Helpers;
 /// <typeparam name="T"></typeparam>
 public sealed class CharacterMap<T> where T : class
 {
-#if NETCOREAPP3_1_OR_GREATER
-    private readonly Vector128<byte> _asciiBitmap;
-#endif
-
-    private readonly T[] asciiMap;
-    private readonly Dictionary<uint, T>? nonAsciiMap;
-    private readonly BoolVector128 isOpeningCharacter;
+    private readonly SearchValues<char> _values;
+    private readonly T[] _asciiMap;
+    private readonly Dictionary<uint, T>? _nonAsciiMap;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="CharacterMap{T}"/> class.
@@ -35,64 +27,38 @@ public sealed class CharacterMap<T> where T : class
     public CharacterMap(IEnumerable<KeyValuePair<char, T>> maps)
     {
         if (maps is null) ThrowHelper.ArgumentNullException(nameof(maps));
+
         var charSet = new HashSet<char>();
-        int maxChar = 0;
 
         foreach (var map in maps)
         {
-            var openingChar = map.Key;
-            charSet.Add(openingChar);
-
-            if (openingChar < 128)
-            {
-                maxChar = Math.Max(maxChar, openingChar);
-
-                if (openingChar == 0)
-                {
-                    ThrowHelper.ArgumentOutOfRangeException("Null is not a valid opening character.", nameof(maps));
-                }
-            }
-            else
-            {
-                nonAsciiMap ??= new Dictionary<uint, T>();
-            }
+            charSet.Add(map.Key);
         }
 
-        OpeningCharacters = charSet.ToArray();
+        OpeningCharacters = [.. charSet];
         Array.Sort(OpeningCharacters);
 
-        asciiMap = new T[maxChar + 1];
+        _asciiMap = new T[128];
 
         foreach (var state in maps)
         {
             char openingChar = state.Key;
             if (openingChar < 128)
             {
-                asciiMap[openingChar] ??= state.Value;
-                isOpeningCharacter.Set(openingChar);
+                _asciiMap[openingChar] ??= state.Value;
             }
-            else if (!nonAsciiMap!.ContainsKey(openingChar))
+            else
             {
-                nonAsciiMap[openingChar] = state.Value;
+                _nonAsciiMap ??= new Dictionary<uint, T>();
+
+                if (!_nonAsciiMap.ContainsKey(openingChar))
+                {
+                    _nonAsciiMap[openingChar] = state.Value;
+                }
             }
         }
 
-#if NETCOREAPP3_1_OR_GREATER
-        if (nonAsciiMap is null)
-        {
-            long bitmap_0_3 = 0;
-            long bitmap_4_7 = 0;
-
-            foreach (char openingChar in OpeningCharacters)
-            {
-                int position = (openingChar >> 4) | ((openingChar & 0x0F) << 3);
-                if (position < 64) bitmap_0_3 |= 1L << position;
-                else bitmap_4_7 |= 1L << (position - 64);
-            }
-
-            _asciiBitmap = Vector128.Create(bitmap_0_3, bitmap_4_7).AsByte();
-        }
-#endif
+        _values = SearchValues.Create(OpeningCharacters);
     }
 
     /// <summary>
@@ -110,7 +76,7 @@ public sealed class CharacterMap<T> where T : class
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         get
         {
-            T[] asciiMap = this.asciiMap;
+            T[] asciiMap = _asciiMap;
             if (openingChar < (uint)asciiMap.Length)
             {
                 return asciiMap[openingChar];
@@ -118,13 +84,12 @@ public sealed class CharacterMap<T> where T : class
             else
             {
                 T? map = null;
-                nonAsciiMap?.TryGetValue(openingChar, out map);
+                _nonAsciiMap?.TryGetValue(openingChar, out map);
                 return map;
             }
         }
     }
 
-
     /// <summary>
     /// Searches for an opening character from a registered parser in the specified string.
     /// </summary>
@@ -132,167 +97,20 @@ public sealed class CharacterMap<T> where T : class
     /// <param name="start">The start.</param>
     /// <param name="end">The end.</param>
     /// <returns>Index position within the string of the first opening character found in the specified text; if not found, returns -1</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public int IndexOfOpeningCharacter(string text, int start, int end)
     {
         Debug.Assert(text is not null);
-        Debug.Assert(start >= 0 && end >= 0);
-        Debug.Assert(end - start + 1 >= 0);
-        Debug.Assert(end - start + 1 <= text.Length);
 
-        if (nonAsciiMap is null)
+        ReadOnlySpan<char> span = text.AsSpan(start, end - start + 1);
+
+        int index = span.IndexOfAny(_values);
+
+        if (index >= 0)
         {
-#if NETCOREAPP3_1_OR_GREATER
-            if (Ssse3.IsSupported && BitConverter.IsLittleEndian)
-            {
-                // Based on http://0x80.pl/articles/simd-byte-lookup.html#universal-algorithm
-                // Optimized for sets in the [1, 127] range
-
-                int lengthMinusOne = end - start;
-                int charsToProcessVectorized = lengthMinusOne & ~(2 * Vector128<short>.Count - 1);
-                int finalStart = start + charsToProcessVectorized;
-
-                if (start < finalStart)
-                {
-                    ref char textStartRef = ref Unsafe.Add(ref Unsafe.AsRef(in text.GetPinnableReference()), start);
-                    Vector128<byte> bitmap = _asciiBitmap;
-                    do
-                    {
-                        // Load 32 bytes (16 chars) into two Vector128<short>s (chars)
-                        // Drop the high byte of each char
-                        // Pack the remaining bytes into a single Vector128<byte>
-                        Vector128<byte> input = Sse2.PackUnsignedSaturate(
-                            Unsafe.ReadUnaligned<Vector128<short>>(ref Unsafe.As<char, byte>(ref textStartRef)),
-                            Unsafe.ReadUnaligned<Vector128<short>>(ref Unsafe.As<char, byte>(ref Unsafe.Add(ref textStartRef, Vector128<short>.Count))));
-
-                        // Extract the higher nibble of each character ((input >> 4) & 0xF)
-                        Vector128<byte> higherNibbles = Sse2.And(Sse2.ShiftRightLogical(input.AsUInt16(), 4).AsByte(), Vector128.Create((byte)0xF));
-
-                        // Lookup the matching higher nibble for each character based on the lower nibble
-                        // PSHUFB will set the result to 0 for any non-ASCII (> 127) character
-                        Vector128<byte> bitsets = Ssse3.Shuffle(bitmap, input);
-
-                        // Calculate a bitmask (1 << (higherNibble % 8)) for each character
-                        Vector128<byte> bitmask = Ssse3.Shuffle(Vector128.Create(0x8040201008040201).AsByte(), higherNibbles);
-
-                        // Check which characters are present in the set
-                        // We are relying on bitsets being zero for non-ASCII characters
-                        Vector128<byte> result = Sse2.And(bitsets, bitmask);
-
-                        if (!result.Equals(Vector128<byte>.Zero))
-                        {
-                            int resultMask = ~Sse2.MoveMask(Sse2.CompareEqual(result, Vector128<byte>.Zero));
-                            return start + BitOperations.TrailingZeroCount((uint)resultMask);
-                        }
-
-                        start += 2 * Vector128<short>.Count;
-                        textStartRef = ref Unsafe.Add(ref textStartRef, 2 * Vector128<short>.Count);
-                    }
-                    while (start != finalStart);
-                }
-            }
-
-            ref char textRef = ref Unsafe.AsRef(in text.GetPinnableReference());
-            for (; start <= end; start++)
-            {
-                if (IntPtr.Size == 4)
-                {
-                    uint c = Unsafe.Add(ref textRef, start);
-                    if (c < 128 && isOpeningCharacter[c])
-                    {
-                        return start;
-                    }
-                }
-                else
-                {
-                    ulong c = Unsafe.Add(ref textRef, start);
-                    if (c < 128 && isOpeningCharacter[c])
-                    {
-                        return start;
-                    }
-                }
-            }
-#else
-            unsafe
-            {
-                fixed (char* pText = text)
-                {
-                    for (int i = start; i <= end; i++)
-                    {
-                        char c = pText[i];
-                        if (c < 128 && isOpeningCharacter[c])
-                        {
-                            return i;
-                        }
-                    }
-                }
-            }
-#endif
-            return -1;
+            index += start;
         }
-        else
-        {
-            return IndexOfOpeningCharacterNonAscii(text, start, end);
-        }
-    }
 
-    private int IndexOfOpeningCharacterNonAscii(string text, int start, int end)
-    {
-#if NETCOREAPP3_1_OR_GREATER
-        ref char textRef = ref Unsafe.AsRef(in text.GetPinnableReference());
-        for (int i = start; i <= end; i++)
-        {
-            char c = Unsafe.Add(ref textRef, i);
-            if (c < 128 ? isOpeningCharacter[c] : nonAsciiMap!.ContainsKey(c))
-            {
-                return i;
-            }
-        }
-#else
-        unsafe
-        {
-            fixed (char* pText = text)
-            {
-                for (int i = start; i <= end; i++)
-                {
-                    char c = pText[i];
-                    if (c < 128 ? isOpeningCharacter[c] : nonAsciiMap!.ContainsKey(c))
-                    {
-                        return i;
-                    }
-                }
-            }
-        }
-#endif
-        return -1;
+        return index;
     }
 }
-
-internal unsafe struct BoolVector128
-{
-    private fixed bool values[128];
-
-    public void Set(char c)
-    {
-        Debug.Assert(c < 128);
-        values[c] = true;
-    }
-
-    public readonly bool this[uint c]
-    {
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        get
-        {
-            Debug.Assert(c < 128);
-            return values[c];
-        }
-    }
-    public readonly bool this[ulong c]
-    {
-        [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        get
-        {
-            Debug.Assert(c < 128 && IntPtr.Size == 8);
-            return values[c];
-        }
-    }
-}

src/Markdig/Helpers/EntityHelper.cs

@@ -31,6 +31,8 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+using System.Text;
+
 namespace Markdig.Helpers;
 
 /// <summary>
@@ -57,41 +59,31 @@ public static class EntityHelper
     /// <returns>The unicode character set or <c>null</c> if the entity was not recognized.</returns>
     public static string DecodeEntity(int utf32)
     {
-        if (!CharHelper.IsInInclusiveRange(utf32, 1, 1114111) || CharHelper.IsInInclusiveRange(utf32, 55296, 57343))
+        if (utf32 == 0 || !UnicodeUtility.IsValidUnicodeScalar((uint)utf32))
             return CharHelper.ReplacementCharString;
 
-        if (utf32 < 65536)
+        if (UnicodeUtility.IsBmpCodePoint((uint)utf32))
             return char.ToString((char)utf32);
 
-        utf32 -= 65536;
-        return new string(
-#if NETSTANDARD2_1_OR_GREATER || NETCOREAPP3_1_OR_GREATER
-            stackalloc
-#else
-            new
-#endif
-            char[]
-        {
-            (char)((uint)utf32 / 1024 + 55296),
-            (char)((uint)utf32 % 1024 + 56320)
-        });
+        UnicodeUtility.GetUtf16SurrogatesFromSupplementaryPlaneScalar((uint)utf32, out char high, out char low);
+        return new string([high, low]);
     }
 
     internal static void DecodeEntity(int utf32, ref ValueStringBuilder sb)
     {
-        if (!CharHelper.IsInInclusiveRange(utf32, 1, 1114111) || CharHelper.IsInInclusiveRange(utf32, 55296, 57343))
+        if (utf32 == 0 || !UnicodeUtility.IsValidUnicodeScalar((uint)utf32))
         {
             sb.Append(CharHelper.ReplacementChar);
         }
-        else if (utf32 < 65536)
+        else if (UnicodeUtility.IsBmpCodePoint((uint)utf32))
         {
             sb.Append((char)utf32);
         }
         else
         {
-            utf32 -= 65536;
-            sb.Append((char)((uint)utf32 / 1024 + 55296));
-            sb.Append((char)((uint)utf32 % 1024 + 56320));
+            UnicodeUtility.GetUtf16SurrogatesFromSupplementaryPlaneScalar((uint)utf32, out char high, out char low);
+            sb.Append(high);
+            sb.Append(low);
         }
     }
 

src/Markdig/Helpers/FastStringWriter.cs

@@ -278,8 +278,7 @@ internal sealed class FastStringWriter : TextWriter
         _pos = 0;
     }
 
-    public override string ToString()
-    {
-        return _chars.AsSpan(0, _pos).ToString();
-    }
+    public override string ToString() => AsSpan().ToString();
+
+    public ReadOnlySpan<char> AsSpan() => _chars.AsSpan(0, _pos);
 }

src/Markdig/Helpers/HexConverter.cs

@@ -0,0 +1,27 @@
+// Copyright (c) Alexandre Mutel. All rights reserved.
+// This file is licensed under the BSD-Clause 2 license.
+// See the license.txt file in the project root for more information.
+
+using System.Runtime.CompilerServices;
+
+namespace Markdig.Helpers;
+
+// Based on https://github.com/dotnet/runtime/blob/main/src/libraries/Common/src/System/HexConverter.cs
+internal static class HexConverter
+{
+    public enum Casing : uint
+    {
+        Upper = 0,
+        Lower = 0x2020U,
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static void ToCharsBuffer(byte value, Span<char> buffer, int startingIndex = 0, Casing casing = Casing.Upper)
+    {
+        uint difference = (((uint)value & 0xF0U) << 4) + ((uint)value & 0x0FU) - 0x8989U;
+        uint packedResult = ((((uint)(-(int)difference) & 0x7070U) >> 4) + difference + 0xB9B9U) | (uint)casing;
+
+        buffer[startingIndex + 1] = (char)(packedResult & 0xFF);
+        buffer[startingIndex] = (char)(packedResult >> 8);
+    }
+}

src/Markdig/Helpers/HtmlHelper.cs

@@ -12,8 +12,8 @@ namespace Markdig.Helpers;
 /// </summary>
 public static class HtmlHelper
 {
-    private static readonly char[] SearchBackAndAmp = { '\\', '&' };
-    private static readonly char[] SearchAmp = { '&' };
+    private static readonly char[] SearchBackAndAmp = ['\\', '&'];
+    private static readonly char[] SearchAmp = ['&'];
     private static readonly string[] EscapeUrlsForAscii = new string[128];
 
     static HtmlHelper()

src/Markdig/Helpers/LineReader.cs

@@ -53,7 +53,7 @@ public struct LineReader
         else
         {
 #if NETCOREAPP3_1_OR_GREATER
-            ReadOnlySpan<char> span = MemoryMarshal.CreateReadOnlySpan(ref Unsafe.Add(ref Unsafe.AsRef(text.GetPinnableReference()), sourcePosition), end - sourcePosition);
+            ReadOnlySpan<char> span = MemoryMarshal.CreateReadOnlySpan(ref Unsafe.Add(ref Unsafe.AsRef(in text.GetPinnableReference()), sourcePosition), end - sourcePosition);
 #else
             ReadOnlySpan<char> span = text.AsSpan(sourcePosition);
 #endif
@@ -65,7 +65,7 @@ public struct LineReader
                 newSourcePosition = end + 1;
 
 #if NETCOREAPP3_1_OR_GREATER
-                if (Unsafe.Add(ref Unsafe.AsRef(text.GetPinnableReference()), end) == '\r')
+                if (Unsafe.Add(ref Unsafe.AsRef(in text.GetPinnableReference()), end) == '\r')
 #else
                 if ((uint)end < (uint)text.Length && text[end] == '\r')
 #endif

src/Markdig/Helpers/LinkHelper.cs

@@ -19,6 +19,11 @@ public static class LinkHelper
     }
 
     public static string Urilize(string headingText, bool allowOnlyAscii, bool keepOpeningDigits = false)
+    {
+        return Urilize(headingText.AsSpan(), allowOnlyAscii, keepOpeningDigits);
+    }
+
+    public static string Urilize(ReadOnlySpan<char> headingText, bool allowOnlyAscii, bool keepOpeningDigits = false)
     {
         var headingBuffer = new ValueStringBuilder(stackalloc char[ValueStringBuilder.StackallocThreshold]);
         bool hasLetter = keepOpeningDigits && headingText.Length > 0 && char.IsLetterOrDigit(headingText[0]);
@@ -95,15 +100,24 @@ public static class LinkHelper
     }
 
     public static string UrilizeAsGfm(string headingText)
+    {
+        return UrilizeAsGfm(headingText.AsSpan());
+    }
+
+    public static string UrilizeAsGfm(ReadOnlySpan<char> headingText)
     {
         // Following https://github.com/jch/html-pipeline/blob/master/lib/html/pipeline/toc_filter.rb
         var headingBuffer = new ValueStringBuilder(stackalloc char[ValueStringBuilder.StackallocThreshold]);
         for (int i = 0; i < headingText.Length; i++)
         {
             var c = headingText[i];
-            if (char.IsLetterOrDigit(c) || c == ' ' || c == '-' || c == '_')
+            if (char.IsLetterOrDigit(c) || c == '-' || c == '_')
             {
-                headingBuffer.Append(c == ' ' ? '-' : char.ToLowerInvariant(c));
+                headingBuffer.Append(char.ToLowerInvariant(c));
+            }
+            else if (c == ' ')
+            {
+                headingBuffer.Append('-');
             }
         }
         return headingBuffer.ToString();

src/Markdig/Helpers/ObjectCache.cs

@@ -36,7 +36,7 @@ public abstract class ObjectCache<T> where T : class
     /// <returns></returns>
     public T Get()
     {
-        if (_builders.TryDequeue(out T instance))
+        if (_builders.TryDequeue(out T? instance))
         {
             return instance;
         }

src/Markdig/Helpers/StringLineGroup.cs

@@ -187,9 +187,32 @@ public struct StringLineGroup : IEnumerable
         }
     }
 
-    IEnumerator IEnumerable.GetEnumerator()
+    public struct Enumerator(StringLineGroup parent) : IEnumerator
     {
-        return Lines.GetEnumerator();
+        private readonly StringLineGroup _parent = parent;
+        private int _index = -1;
+
+        public object Current => _parent.Lines[_index];
+
+        public bool MoveNext()
+        {
+            return ++_index < _parent.Count;
+        }
+
+        public void Reset()
+        {
+            _index = -1;
+        }
+    }
+    
+    public Enumerator GetEnumerator()
+    {
+        return new Enumerator(this);
+    }
+
+    IEnumerator IEnumerable.GetEnumerator() 
+    {
+        return GetEnumerator();
     }
 
     private void IncreaseCapacity()
@@ -423,25 +446,21 @@ public struct StringLineGroup : IEnumerable
         }
     }
 
-    public readonly struct LineOffset
+    public readonly struct LineOffset(
+        int linePosition,
+        int column,
+        int offset,
+        int start,
+        int end)
     {
-        public LineOffset(int linePosition, int column, int offset, int start, int end)
-        {
-            LinePosition = linePosition;
-            Column = column;
-            Offset = offset;
-            Start = start;
-            End = end;
-        }
+        public readonly int LinePosition = linePosition;
 
-        public readonly int LinePosition;
+        public readonly int Column = column;
 
-        public readonly int Column;
+        public readonly int Offset = offset;
 
-        public readonly int Offset;
+        public readonly int Start = start;
 
-        public readonly int Start;
-
-        public readonly int End;
+        public readonly int End = end;
     }
-}
+}

src/Markdig/Helpers/StringSlice.cs

@@ -475,7 +475,7 @@ public struct StringSlice : ICharIterator
         }
 
 #if NETCOREAPP3_1_OR_GREATER
-        return MemoryMarshal.CreateReadOnlySpan(ref Unsafe.Add(ref Unsafe.AsRef(text.GetPinnableReference()), start), length);
+        return MemoryMarshal.CreateReadOnlySpan(ref Unsafe.Add(ref Unsafe.AsRef(in text.GetPinnableReference()), start), length);
 #else
         return text.AsSpan(start, length);
 #endif

src/Markdig/Helpers/ThrowHelper.cs

@@ -80,7 +80,7 @@ internal static class ThrowHelper
         if (depth > limit)
             DepthLimitExceeded();
 
-        [MethodImpl(MethodImplOptions.NoInlining)]
+        [DoesNotReturn]
         static void DepthLimitExceeded() => throw new ArgumentException("Markdown elements in the input are too deeply nested - depth limit exceeded. Input is most likely not sensible or is a very large table.");
     }
 

src/Markdig/Helpers/UnicodeUtility.cs

@@ -0,0 +1,30 @@
+// Copyright (c) Alexandre Mutel. All rights reserved.
+// This file is licensed under the BSD-Clause 2 license.
+// See the license.txt file in the project root for more information.
+
+using System.Diagnostics;
+using System.Runtime.CompilerServices;
+
+namespace System.Text;
+
+// Based on https://github.com/dotnet/runtime/blob/main/src/libraries/System.Private.CoreLib/src/System/Text/UnicodeUtility.cs
+internal static class UnicodeUtility
+{
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool IsBmpCodePoint(uint value) => value <= 0xFFFFu;
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static bool IsValidUnicodeScalar(uint value)
+    {
+        return ((value - 0x110000u) ^ 0xD800u) >= 0xFFEF0800u;
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    public static void GetUtf16SurrogatesFromSupplementaryPlaneScalar(uint value, out char highSurrogateCodePoint, out char lowSurrogateCodePoint)
+    {
+        Debug.Assert(IsValidUnicodeScalar(value) && IsBmpCodePoint(value));
+
+        highSurrogateCodePoint = (char)((value + ((0xD800u - 0x40u) << 10)) >> 10);
+        lowSurrogateCodePoint = (char)((value & 0x3FFu) + 0xDC00u);
+    }
+}

src/Markdig/Markdig.targets

@@ -5,7 +5,7 @@
     <Copyright>Alexandre Mutel</Copyright>
     <NeutralLanguage>en-US</NeutralLanguage>
     <Authors>Alexandre Mutel</Authors>
-    <TargetFrameworks>net462;netstandard2.0;netstandard2.1;net6.0</TargetFrameworks>
+    <TargetFrameworks>net462;netstandard2.0;netstandard2.1;net6.0;net8.0</TargetFrameworks>
     <CheckEolTargetFramework>false</CheckEolTargetFramework>
     <PackageTags>Markdown CommonMark md html md2html</PackageTags>
     <PackageReleaseNotes>https://github.com/lunet-io/markdig/blob/master/changelog.md</PackageReleaseNotes>
@@ -14,7 +14,7 @@
     <PackageIcon>markdig.png</PackageIcon>
     <PackageProjectUrl>https://github.com/lunet-io/markdig</PackageProjectUrl>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <LangVersion>10</LangVersion>
+    <LangVersion>12</LangVersion>
     <Nullable>enable</Nullable>
     <NoWarn>$(NoWarn);CS1591</NoWarn>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
@@ -24,22 +24,18 @@
     <SymbolPackageFormat>snupkg</SymbolPackageFormat>
   </PropertyGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'net462' ">
-    <PackageReference Include="System.Memory" Version="4.5.4" />
+  <ItemGroup Condition=" '$(TargetFramework)' == 'net462' OR  '$(TargetFramework)' == 'netstandard2.0'">
+    <PackageReference Include="System.Memory" Version="4.5.5" />
   </ItemGroup>
 
-  <ItemGroup Condition=" '$(TargetFramework)' == 'netstandard2.0' ">
-    <PackageReference Include="System.Memory" Version="4.5.4" />
-  </ItemGroup>
-  
   <ItemGroup>
     <None Include="../../img/markdig.png" Pack="true" PackagePath="" />
     <None Include="../../readme.md" Pack="true" PackagePath="/"/>
-    <PackageReference Include="MinVer" Version="3.1.0">
+    <PackageReference Include="MinVer" Version="4.3.0">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.*" PrivateAssets="All"/>
+    <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.*" PrivateAssets="All"/>
   </ItemGroup>
 
   <Target Name="PatchVersion" AfterTargets="MinVer">

src/Markdig/Markdown.cs

@@ -19,16 +19,10 @@ namespace Markdig;
 /// </summary>
 public static class Markdown
 {
-    public static string Version
-    {
-        get
-        {
-            if (_Version == null)
-                _Version = ((AssemblyFileVersionAttribute)typeof(Markdown).Assembly.GetCustomAttributes(typeof(AssemblyFileVersionAttribute), false).FirstOrDefault())?.Version ?? "Unknown";
-            return _Version;
-        }
-    }
-    private static string? _Version;
+    public static string Version =>
+        s_version ??= typeof(Markdown).Assembly.GetCustomAttribute<AssemblyFileVersionAttribute>()?.Version ?? "Unknown";
+
+    private static string? s_version;
 
     internal static readonly MarkdownPipeline DefaultPipeline = new MarkdownPipelineBuilder().Build();
     private static readonly MarkdownPipeline _defaultTrackTriviaPipeline = new MarkdownPipelineBuilder().EnableTrackTrivia().Build();

src/Markdig/MarkdownPipeline.cs

@@ -95,18 +95,14 @@ public sealed class MarkdownPipeline
         return new RentedHtmlRenderer(cache, renderer);
     }
 
-    internal sealed class HtmlRendererCache : ObjectCache<HtmlRenderer>
+    internal sealed class HtmlRendererCache(
+        MarkdownPipeline pipeline,
+        bool customWriter = false) : ObjectCache<HtmlRenderer>
     {
-        private static readonly TextWriter s_dummyWriter = new FastStringWriter();
+        private static readonly FastStringWriter s_dummyWriter = new();
 
-        private readonly MarkdownPipeline _pipeline;
-        private readonly bool _customWriter;
-
-        public HtmlRendererCache(MarkdownPipeline pipeline, bool customWriter = false)
-        {
-            _pipeline = pipeline;
-            _customWriter = customWriter;
-        }
+        private readonly MarkdownPipeline _pipeline = pipeline;
+        private readonly bool _customWriter = customWriter;
 
         protected override HtmlRenderer NewInstance()
         {

src/Markdig/MarkdownPipelineBuilder.cs

@@ -24,8 +24,8 @@ public class MarkdownPipelineBuilder
     public MarkdownPipelineBuilder()
     {
         // Add all default parsers
-        BlockParsers = new OrderedList<BlockParser>()
-        {
+        BlockParsers =
+        [
             new ThematicBreakParser(),
             new HeadingBlockParser(),
             new QuoteBlockParser(),
@@ -35,10 +35,10 @@ public class MarkdownPipelineBuilder
             new FencedCodeBlockParser(),
             new IndentedCodeBlockParser(),
             new ParagraphBlockParser(),
-        };
+        ];
 
-        InlineParsers = new OrderedList<InlineParser>()
-        {
+        InlineParsers =
+        [
             new HtmlEntityParser(),
             new LinkInlineParser(),
             new EscapeInlineParser(),
@@ -46,7 +46,7 @@ public class MarkdownPipelineBuilder
             new CodeInlineParser(),
             new AutolinkInlineParser(),
             new LineBreakInlineParser(),
-        };
+        ];
 
         Extensions = new OrderedList<IMarkdownExtension>();
     }

src/Markdig/Parsers/BlockProcessor.cs

@@ -152,7 +152,7 @@ public class BlockProcessor
     /// <summary>
     /// Gets the current stack of <see cref="Block"/> being processed.
     /// </summary>
-    private List<BlockWrapper> OpenedBlocks { get; } = new();
+    private List<BlockWrapper> OpenedBlocks { get; } = [];
 
     private bool ContinueProcessingLine { get; set; }
 

src/Markdig/Parsers/FencedBlockParserBase.cs

@@ -40,7 +40,8 @@ public abstract class FencedBlockParserBase : BlockParser, IAttributesParseable
 /// <seealso cref="BlockParser" />
 public abstract class FencedBlockParserBase<T> : FencedBlockParserBase where T : Block, IFencedBlock
 {
-    private static readonly TransformedStringCache _infoStringCache = new(static infoString => HtmlHelper.Unescape(infoString));
+    private static readonly TransformedStringCache s_infoStringCache = new(static infoString => HtmlHelper.Unescape(infoString));
+    private static readonly TransformedStringCache s_argumentsStringCache = new(static argumentsString => HtmlHelper.Unescape(argumentsString));
     private TransformedStringCache? _infoPrefixCache;
 
     /// <summary>
@@ -176,7 +177,7 @@ public abstract class FencedBlockParserBase<T> : FencedBlockParserBase where T :
 
     end:
         fenced.TriviaAfterFencedChar = afterFence;
-        fenced.Info = _infoStringCache.Get(info.AsSpan());
+        fenced.Info = s_infoStringCache.Get(info.AsSpan());
         fenced.UnescapedInfo = info;
         fenced.TriviaAfterInfo = afterInfo;
         fenced.Arguments = HtmlHelper.Unescape(arg.ToString());
@@ -197,71 +198,47 @@ public abstract class FencedBlockParserBase<T> : FencedBlockParserBase where T :
     /// <returns><c>true</c> if parsing of the line is successfull; <c>false</c> otherwise</returns>
     public static bool DefaultInfoParser(BlockProcessor state, ref StringSlice line, IFencedBlock fenced, char openingCharacter)
     {
-        // An info string cannot contain any backticks (unless it is a tilde block)
         int firstSpace = -1;
-        if (openingCharacter == '`')
+        ReadOnlySpan<char> lineSpan = line.AsSpan();
+
+        if (!lineSpan.IsEmpty)
         {
-            for (int i = line.Start; i <= line.End; i++)
+            if (openingCharacter == '`')
             {
-                char c = line.Text[i];
-                if (c == '`')
+                firstSpace = lineSpan.IndexOfAny(' ', '\t', '`');
+
+                // An info string cannot contain any backticks (unless it is a tilde block)
+                if (firstSpace >= 0 && lineSpan.Slice(firstSpace).Contains('`'))
                 {
                     return false;
                 }
-
-                if (firstSpace < 0 && c.IsSpaceOrTab())
-                {
-                    firstSpace = i;
-                }
             }
-        }
-        else
-        {
-            for (int i = line.Start; i <= line.End; i++)
+            else
             {
-                if (line.Text[i].IsSpaceOrTab())
-                {
-                    firstSpace = i;
-                    break;
-                }
+                firstSpace = lineSpan.IndexOfAny(' ', '\t');
             }
         }
 
         StringSlice infoStringSlice;
-        string? argString = null;
 
-        if (firstSpace > 0)
+        if (firstSpace >= 0)
         {
+            firstSpace += line.Start;
             infoStringSlice = new StringSlice(line.Text, line.Start, firstSpace - 1);
 
-            // Skip any spaces after info string
-            firstSpace++;
-            while (firstSpace <= line.End)
-            {
-                char c = line[firstSpace];
-                if (c.IsSpaceOrTab())
-                {
-                    firstSpace++;
-                }
-                else
-                {
-                    break;
-                }
-            }
-
             var argStringSlice = new StringSlice(line.Text, firstSpace, line.End);
             argStringSlice.Trim();
-            argString = argStringSlice.ToString();
+            fenced.Arguments = s_argumentsStringCache.Get(argStringSlice.AsSpan());
         }
         else
         {
             infoStringSlice = line;
+            fenced.Arguments = string.Empty;
         }
 
         infoStringSlice.Trim();
 
-        fenced.Info = _infoStringCache.Get(infoStringSlice.AsSpan());
-        fenced.Arguments = HtmlHelper.Unescape(argString);
+        fenced.Info = s_infoStringCache.Get(infoStringSlice.AsSpan());
 
         return true;
     }
@@ -303,17 +280,19 @@ public abstract class FencedBlockParserBase<T> : FencedBlockParserBase where T :
         // Try to parse any attached attributes
         TryParseAttributes?.Invoke(processor, ref line, fenced);
 
-        // If the info parser was not successfull, early exit
+        // If the info parser was not successful, early exit
         if (InfoParser != null && !InfoParser(processor, ref line, fenced, matchChar))
         {
             return BlockState.None;
         }
 
         // Add the language as an attribute by default
-        if (!string.IsNullOrEmpty(fenced.Info))
+        string? info = fenced.Info;
+
+        if (!string.IsNullOrEmpty(info))
         {
             Debug.Assert(_infoPrefixCache is not null || InfoPrefix is null);
-            string infoWithPrefix = _infoPrefixCache?.Get(fenced.Info!) ?? fenced.Info!;
+            string infoWithPrefix = _infoPrefixCache?.Get(info!) ?? info!;
             fenced.GetAttributes().AddClass(infoWithPrefix);
         }
 
@@ -329,34 +308,32 @@ public abstract class FencedBlockParserBase<T> : FencedBlockParserBase where T :
     public override BlockState TryContinue(BlockProcessor processor, Block block)
     {
         var fence = (IFencedBlock)block;
-        var openingCount = fence.OpeningFencedCharCount;
 
         // Match if we have a closing fence
         var line = processor.Line;
         var sourcePosition = processor.Start;
         var closingCount = line.CountAndSkipChar(fence.FencedChar);
-        var diff = openingCount - closingCount;
 
         char c = line.CurrentChar;
-        var lastFenceCharPosition = processor.Start + closingCount;
 
         // If we have a closing fence, close it and discard the current line
         // The line must contain only fence opening character followed only by whitespaces.
         var startBeforeTrim = line.Start;
-        var endBeforeTrim = line.End;
-        var trimmed = line.TrimEnd();
-        if (diff <= 0 && !processor.IsCodeIndent && (c == '\0' || c.IsWhitespace()) && trimmed)
+
+        if (fence.OpeningFencedCharCount <= closingCount &&
+            !processor.IsCodeIndent &&
+            (c == '\0' || c.IsWhitespace()) &&
+            line.TrimEnd())
         {
             block.UpdateSpanEnd(startBeforeTrim - 1);
 
-            var fencedBlock = (IFencedBlock)block;
-            fencedBlock.ClosingFencedCharCount = closingCount;
+            fence.ClosingFencedCharCount = closingCount;
 
             if (processor.TrackTrivia)
             {
-                fencedBlock.NewLine = processor.Line.NewLine;
-                fencedBlock.TriviaBeforeClosingFence = processor.UseTrivia(sourcePosition - 1);
-                fencedBlock.TriviaAfter = new StringSlice(processor.Line.Text, lastFenceCharPosition, endBeforeTrim);
+                fence.NewLine = line.NewLine;
+                fence.TriviaBeforeClosingFence = processor.UseTrivia(sourcePosition - 1);
+                fence.TriviaAfter = new StringSlice(line.Text, processor.Start + closingCount, processor.Line.End);
             }
 
             // Don't keep the last line

src/Markdig/Parsers/FencedCodeBlockParser.cs

@@ -20,7 +20,7 @@ public class FencedCodeBlockParser : FencedBlockParserBase<FencedCodeBlock>
     /// </summary>
     public FencedCodeBlockParser()
     {
-        OpeningCharacters = new[] {'`', '~'};
+        OpeningCharacters = ['`', '~'];
         InfoPrefix = DefaultInfoPrefix;
     }
 

src/Markdig/Parsers/HeadingBlockParser.cs

@@ -20,7 +20,7 @@ public class HeadingBlockParser : BlockParser, IAttributesParseable
     /// </summary>
     public HeadingBlockParser()
     {
-        OpeningCharacters = new[] {'#'};
+        OpeningCharacters = ['#'];
     }
 
     /// <summary>

src/Markdig/Parsers/HtmlBlockParser.cs

@@ -18,7 +18,7 @@ public class HtmlBlockParser : BlockParser
     /// </summary>
     public HtmlBlockParser()
     {
-        OpeningCharacters = new[] { '<' };
+        OpeningCharacters = ['<'];
     }
        
     public override BlockState TryOpen(BlockProcessor processor)

src/Markdig/Parsers/InlineProcessor.cs

@@ -26,7 +26,7 @@ public delegate void ProcessInlineDelegate(InlineProcessor processor, Inline? in
 /// </summary>
 public class InlineProcessor
 {
-    private readonly List<StringLineGroup.LineOffset> lineOffsets = new();
+    private readonly List<StringLineGroup.LineOffset> lineOffsets = [];
     private int previousSliceOffset;
     private int previousLineIndexForSliceOffset;
 
@@ -225,6 +225,7 @@ public class InlineProcessor
         previousLineIndexForSliceOffset = 0;
         lineOffsets.Clear();
         var text = leafBlock.Lines.ToSlice(lineOffsets);
+        var textEnd = text.End;
         leafBlock.Lines.Release();
         int previousStart = -1;
 
@@ -319,7 +320,8 @@ public class InlineProcessor
                 var newLine = leafBlock.NewLine;
                 if (newLine != NewLine.None)
                 {
-                    leafBlock.Inline.AppendChild(new LineBreakInline { NewLine = newLine });
+                    var position = GetSourcePosition(textEnd + 1, out int line, out int column);
+                    leafBlock.Inline.AppendChild(new LineBreakInline { NewLine = newLine, Line = line, Column = column, Span = { Start = position, End = position + (newLine == NewLine.CarriageReturnLineFeed ? 1 : 0) } });
                 }
             }
         }
@@ -342,6 +344,12 @@ public class InlineProcessor
         //    DebugLog.WriteLine("** Dump after Emphasis:");
         //    leafBlock.Inline.DumpTo(DebugLog);
         //}
+
+        if (leafBlock.Inline.LastChild is not null)
+        {
+            leafBlock.Inline.Span.End = leafBlock.Inline.LastChild.Span.End;
+            leafBlock.UpdateSpanEnd(leafBlock.Inline.Span.End);
+        }
     }
 
     public void PostProcessInlines(int startingIndex, Inline? root, Inline? lastChild, bool isFinalProcessing)

src/Markdig/Parsers/Inlines/AutolinkInlineParser.cs

@@ -19,7 +19,7 @@ public class AutolinkInlineParser : InlineParser
     /// </summary>
     public AutolinkInlineParser()
     {
-        OpeningCharacters = new[] {'<'};
+        OpeningCharacters = ['<'];
         EnableHtmlParsing = true;
     }
 

src/Markdig/Parsers/Inlines/CodeInlineParser.cs

@@ -21,27 +21,21 @@ public class CodeInlineParser : InlineParser
     /// </summary>
     public CodeInlineParser()
     {
-        OpeningCharacters = new[] { '`' };
+        OpeningCharacters = ['`'];
     }
 
     public override bool Match(InlineProcessor processor, ref StringSlice slice)
     {
-        var match = slice.CurrentChar;
+        char match = slice.CurrentChar;
         if (slice.PeekCharExtra(-1) == match)
         {
             return false;
         }
 
-        var startPosition = slice.Start;
+        Debug.Assert(match is not ('\r' or '\n'));
 
         // Match the opened sticks
         int openSticks = slice.CountAndSkipChar(match);
-        int contentStart = slice.Start;
-        int closeSticks = 0;
-
-        char c = slice.CurrentChar;
-
-        var builder = new ValueStringBuilder(stackalloc char[ValueStringBuilder.StackallocThreshold]);
 
         // A backtick string is a string of one or more backtick characters (`) that is neither preceded nor followed by a backtick.
         // A code span begins with a backtick string and ends with a backtick string of equal length.
@@ -54,91 +48,106 @@ public class CodeInlineParser : InlineParser
         // This allows you to include code that begins or ends with backtick characters, which must be separated by
         // whitespace from the opening or closing backtick strings.
 
-        bool allSpace = true;
-        bool containsNewLine = false;
-        var contentEnd = -1;
+        ReadOnlySpan<char> span = slice.AsSpan();
+        bool containsNewLines = false;
 
-        while (c != '\0')
+        while (true)
         {
-            // Transform '\n' into a single space
-            if (c == '\n')
+            int i = span.IndexOfAny('\r', '\n', match);
+
+            if ((uint)i >= (uint)span.Length)
             {
-                containsNewLine = true;
-                c = ' ';
-            }
-            else if (c == '\r')
-            {
-                containsNewLine = true;
-                slice.SkipChar();
-                c = slice.CurrentChar;
-                continue;
+                // We got to the end of the input before seeing the match character. CodeInline can't match here.
+                return false;
             }
 
-            if (c == match)
+            int closeSticks = 0;
+
+            while ((uint)i < (uint)span.Length && span[i] == match)
             {
-                contentEnd = slice.Start;
-                closeSticks = slice.CountAndSkipChar(match);
-
-                if (openSticks == closeSticks)
-                {
-                    break;
-                }
-
-                allSpace = false;
-                builder.Append(match, closeSticks);
-                c = slice.CurrentChar;
+                closeSticks++;
+                i++;
             }
-            else
+
+            span = span.Slice(i);
+
+            if (openSticks == closeSticks)
             {
-                builder.Append(c);
-                if (c != ' ')
-                {
-                    allSpace = false;
-                }
-                c = slice.NextChar();
+                break;
+            }
+            else if (closeSticks == 0)
+            {
+                containsNewLines = true;
+                span = span.Slice(1);
             }
         }
 
-        bool isMatching = false;
-        if (closeSticks == openSticks)
+        ReadOnlySpan<char> rawContent = slice.AsSpan().Slice(0, slice.Length - span.Length - openSticks);
+
+        var content = containsNewLines
+            ? new LazySubstring(ReplaceNewLines(rawContent)) // Should be the rare path.
+            : new LazySubstring(slice.Text, slice.Start, rawContent.Length);
+
+        // Remove one space from front and back if the string is not all spaces
+        if (rawContent.Length > 2 &&
+            rawContent[0] is ' ' or '\n' &&
+            rawContent[rawContent.Length - 1] is ' ' or '\n' &&
+            rawContent.ContainsAnyExcept(' ', '\r', '\n'))
         {
-            ReadOnlySpan<char> contentSpan = builder.AsSpan();
-
-            var content = containsNewLine
-                ? new LazySubstring(contentSpan.ToString())
-                : new LazySubstring(slice.Text, contentStart, contentSpan.Length);
-
-            Debug.Assert(contentSpan.SequenceEqual(content.AsSpan()));
-
-            // Remove one space from front and back if the string is not all spaces
-            if (!allSpace && contentSpan.Length > 2 && contentSpan[0] == ' ' && contentSpan[contentSpan.Length - 1] == ' ')
-            {
-                content.Offset++;
-                content.Length -= 2;
-            }
-
-            int delimiterCount = Math.Min(openSticks, closeSticks);
-            var spanStart = processor.GetSourcePosition(startPosition, out int line, out int column);
-            var spanEnd = processor.GetSourcePosition(slice.Start - 1);
-            var codeInline = new CodeInline(content)
-            {
-                Delimiter = match,
-                Span = new SourceSpan(spanStart, spanEnd),
-                Line = line,
-                Column = column,
-                DelimiterCount = delimiterCount,
-            };
-
-            if (processor.TrackTrivia)
-            {
-                codeInline.ContentWithTrivia = new StringSlice(slice.Text, contentStart, contentEnd - 1);
-            }
-
-            processor.Inline = codeInline;
-            isMatching = true;
+            content.Offset++;
+            content.Length -= 2;
         }
 
-        builder.Dispose();
-        return isMatching;
+        int startPosition = slice.Start;
+        slice.Start = startPosition + rawContent.Length + openSticks;
+
+        // We've already skipped the opening sticks. Account for that here.
+        startPosition -= openSticks;
+
+        var codeInline = new CodeInline(content)
+        {
+            Delimiter = slice.Text[startPosition],
+            Span = new SourceSpan(processor.GetSourcePosition(startPosition, out int line, out int column), processor.GetSourcePosition(slice.Start - 1)),
+            Line = line,
+            Column = column,
+            DelimiterCount = openSticks,
+        };
+
+        if (processor.TrackTrivia)
+        {
+            // startPosition and slice.Start include the opening/closing sticks.
+            codeInline.ContentWithTrivia = new StringSlice(slice.Text, startPosition + openSticks, slice.Start - openSticks - 1);
+        }
+
+        processor.Inline = codeInline;
+        return true;
+    }
+
+    private static string ReplaceNewLines(ReadOnlySpan<char> content)
+    {
+        var builder = new ValueStringBuilder(stackalloc char[ValueStringBuilder.StackallocThreshold]);
+
+        while (true)
+        {
+            int i = content.IndexOfAny('\r', '\n');
+
+            if ((uint)i >= (uint)content.Length)
+            {
+                builder.Append(content);
+                break;
+            }
+
+            builder.Append(content.Slice(0, i));
+
+            if (content[i] == '\n')
+            {
+                // Transform '\n' into a single space
+                builder.Append(' ');
+            }
+
+            content = content.Slice(i + 1);
+        }
+
+        return builder.ToString();
     }
 }

src/Markdig/Parsers/Inlines/EmphasisInlineParser.cs

@@ -1,5 +1,5 @@
 // Copyright (c) Alexandre Mutel. All rights reserved.
-// This file is licensed under the BSD-Clause 2 license. 
+// This file is licensed under the BSD-Clause 2 license.
 // See the license.txt file in the project root for more information.
 
 using System.Diagnostics;
@@ -20,7 +20,7 @@ namespace Markdig.Parsers.Inlines;
 public class EmphasisInlineParser : InlineParser, IPostInlineProcessor
 {
     private CharacterMap<EmphasisDescriptor>? emphasisMap;
-    private readonly DelimitersObjectCache inlinesCache = new DelimitersObjectCache();
+    private readonly DelimitersObjectCache inlinesCache = new();
 
     [Obsolete("Use TryCreateEmphasisInlineDelegate instead", error: false)]
     public delegate EmphasisInline CreateEmphasisInlineDelegate(char emphasisChar, bool isStrong);
@@ -31,11 +31,11 @@ public class EmphasisInlineParser : InlineParser, IPostInlineProcessor
     /// </summary>
     public EmphasisInlineParser()
     {
-        EmphasisDescriptors = new List<EmphasisDescriptor>()
-        {
+        EmphasisDescriptors =
+        [
             new EmphasisDescriptor('*', 1, 2, true),
             new EmphasisDescriptor('_', 1, 2, false)
-        };
+        ];
     }
 
     /// <summary>
@@ -65,7 +65,7 @@ public class EmphasisInlineParser : InlineParser, IPostInlineProcessor
     /// </summary>
     [Obsolete("Use TryCreateEmphasisInlineList instead", error: false)]
     public CreateEmphasisInlineDelegate? CreateEmphasisInline { get; set; }
-    public readonly List<TryCreateEmphasisInlineDelegate> TryCreateEmphasisInlineList = new List<TryCreateEmphasisInlineDelegate>();
+    public readonly List<TryCreateEmphasisInlineDelegate> TryCreateEmphasisInlineList = [];
 
     public override void Initialize()
     {
@@ -109,7 +109,7 @@ public class EmphasisInlineParser : InlineParser, IPostInlineProcessor
         var child = container.FirstChild;
         while (child != null)
         {
-            // Stop the search on the delimitation child 
+            // Stop the search on the delimitation child
             if (child == lastChild)
             {
                 break;
@@ -197,7 +197,7 @@ public class EmphasisInlineParser : InlineParser, IPostInlineProcessor
             if (canOpen) delimiterType |= DelimiterType.Open;
             if (canClose) delimiterType |= DelimiterType.Close;
 
-            var delimiter = new EmphasisDelimiterInline(this, emphasisDesc)
+            var delimiter = new EmphasisDelimiterInline(this, emphasisDesc, new StringSlice(slice.Text, startPosition, slice.Start - 1))
             {
                 DelimiterCount = delimiterCount,
                 Type = delimiterType,
@@ -221,7 +221,7 @@ public class EmphasisInlineParser : InlineParser, IPostInlineProcessor
 
         // TODO: Benchmark difference between using List and LinkedList here since there could be a few Remove calls
 
-        // Move current_position forward in the delimiter stack (if needed) until 
+        // Move current_position forward in the delimiter stack (if needed) until
         // we find the first potential closer with delimiter * or _. (This will be the potential closer closest to the beginning of the input – the first one in parse order.)
         for (int i = 0; i < delimiters.Count; i++)
         {
@@ -237,7 +237,7 @@ public class EmphasisInlineParser : InlineParser, IPostInlineProcessor
             {
                 while (true)
                 {
-                    // Now, look back in the stack (staying above stack_bottom and the openers_bottom for this delimiter type) 
+                    // Now, look back in the stack (staying above stack_bottom and the openers_bottom for this delimiter type)
                     // for the first matching potential opener (“matching” means same delimiter).
                     EmphasisDelimiterInline? openDelimiter = null;
                     int openDelimiterIndex = -1;
@@ -307,8 +307,10 @@ public class EmphasisInlineParser : InlineParser, IPostInlineProcessor
                         emphasis.Column = openDelimiter.Column;
                         emphasis.Span.End = closeDelimiter.Span.End - closeDelimitercount + delimiterDelta;
 
+                        openDelimiter.Content.Start += delimiterDelta;
                         openDelimiter.Span.Start += delimiterDelta;
                         openDelimiter.Column += delimiterDelta;
+                        closeDelimiter.Content.Start += delimiterDelta;
                         closeDelimiter.Span.Start += delimiterDelta;
                         closeDelimiter.Column += delimiterDelta;
 
@@ -331,7 +333,7 @@ public class EmphasisInlineParser : InlineParser, IPostInlineProcessor
                         for (int k = i - 1; k >= openDelimiterIndex + 1; k--)
                         {
                             var literalDelimiter = delimiters[k];
-                            literalDelimiter.ReplaceBy(literalDelimiter.AsLiteralInline());                                
+                            literalDelimiter.ReplaceBy(literalDelimiter.AsLiteralInline());
                             delimiters.RemoveAt(k);
                             i--;
                         }

src/Markdig/Parsers/Inlines/EscapeInlineParser.cs

@@ -15,7 +15,7 @@ public class EscapeInlineParser : InlineParser
 {
     public EscapeInlineParser()
     {
-        OpeningCharacters = new[] {'\\'};
+        OpeningCharacters = ['\\'];
     }
 
     public override bool Match(InlineProcessor processor, ref StringSlice slice)

src/Markdig/Parsers/Inlines/HtmlEntityParser.cs

@@ -21,7 +21,7 @@ public class HtmlEntityParser : InlineParser
     /// </summary>
     public HtmlEntityParser()
     {
-        OpeningCharacters = new[] {'&'};
+        OpeningCharacters = ['&'];
     }
 
     public static bool TryParse(ref StringSlice slice, [NotNullWhen(true)] out string? literal, out int match)

src/Markdig/Parsers/Inlines/LineBreakInlineParser.cs

@@ -18,7 +18,7 @@ public class LineBreakInlineParser : InlineParser
     /// </summary>
     public LineBreakInlineParser()
     {
-        OpeningCharacters = new[] { '\n', '\r' };
+        OpeningCharacters = ['\n', '\r'];
     }
 
     /// <summary>

src/Markdig/Parsers/Inlines/LinkInlineParser.cs

@@ -19,7 +19,7 @@ public class LinkInlineParser : InlineParser
     /// </summary>
     public LinkInlineParser()
     {
-        OpeningCharacters = new[] {'[', ']', '!'};
+        OpeningCharacters = ['[', ']', '!'];
     }
 
     public override bool Match(InlineProcessor processor, ref StringSlice slice)
@@ -322,7 +322,7 @@ public class LinkInlineParser : InlineParser
 
         if (label != null || LinkHelper.TryParseLabelTrivia(ref text, true, out label, out labelSpan))
         {
-            SourceSpan labelWithTrivia = new SourceSpan(labelSpan.Start, labelSpan.End);
+            var labelWithTrivia = new SourceSpan(labelSpan.Start, labelSpan.End);
             if (isLabelSpanLocal)
             {
                 labelSpan = inlineState.GetSourcePositionFromLocalSpan(labelSpan);

src/Markdig/Parsers/Inlines/LiteralInlineParser.cs

@@ -32,16 +32,12 @@ public sealed class LiteralInlineParser : InlineParser
 
     public override bool Match(InlineProcessor processor, ref StringSlice slice)
     {
-        var text = slice.Text;
+        string text = slice.Text;
 
-        var startPosition = processor.GetSourcePosition(slice.Start, out int line, out int column);
-
-        // Slightly faster to perform our own search for opening characters
-        var nextStart = processor.Parsers.IndexOfOpeningCharacter(text, slice.Start + 1, slice.End);
-        //var nextStart = str.IndexOfAny(processor.SpecialCharacters, slice.Start + 1, slice.Length - 1);
+        int nextStart = processor.Parsers.IndexOfOpeningCharacter(text, slice.Start + 1, slice.End);
         int length;
 
-        if (nextStart < 0)
+        if ((uint)nextStart >= (uint)text.Length)
         {
             nextStart = slice.End + 1;
             length = nextStart - slice.Start;
@@ -50,10 +46,10 @@ public sealed class LiteralInlineParser : InlineParser
         {
             // Remove line endings if the next char is a new line
             length = nextStart - slice.Start;
+
             if (!processor.TrackTrivia)
             {
-                var nextText = text[nextStart];
-                if (nextText == '\n' || nextText == '\r')
+                if (text[nextStart] is '\n' or '\r')
                 {
                     int end = nextStart - 1;
                     while (length > 0 && text[end].IsSpace())
@@ -86,7 +82,7 @@ public sealed class LiteralInlineParser : InlineParser
                 processor.Inline = new LiteralInline
                 {
                     Content = length > 0 ? newSlice : StringSlice.Empty,
-                    Span = new SourceSpan(startPosition, processor.GetSourcePosition(endPosition)),
+                    Span = new SourceSpan(processor.GetSourcePosition(slice.Start, out int line, out int column), processor.GetSourcePosition(endPosition)),
                     Line = line,
                     Column = column,
                 };

src/Markdig/Parsers/MarkdownParser.cs

@@ -53,34 +53,11 @@ public static class MarkdownParser
         {
             blockProcessor.Open(document);
 
-            ProcessBlocks(blockProcessor, new LineReader(text));
+            ProcessBlocks(blockProcessor, text);
 
             if (pipeline.TrackTrivia)
             {
-                Block? lastBlock = blockProcessor.LastBlock;
-                if (lastBlock is null && document.Count == 0)
-                {
-                    // this means we have unassigned characters
-                    var noBlocksFoundBlock = new EmptyBlock(null);
-                    List<StringSlice> linesBefore = blockProcessor.UseLinesBefore();
-                    noBlocksFoundBlock.LinesAfter = new List<StringSlice>();
-                    if (linesBefore != null)
-                    {
-                        noBlocksFoundBlock.LinesAfter.AddRange(linesBefore);
-                    }
-
-                    document.Add(noBlocksFoundBlock);
-                }
-                else if (lastBlock != null && blockProcessor.LinesBefore != null)
-                {
-                    // this means we're out of lines, but still have unassigned empty lines.
-                    // thus, we'll assign the empty unsassigned lines to the last block
-                    // of the document.
-                    var rootMostContainerBlock = Block.FindRootMostContainerParent(lastBlock);
-                    rootMostContainerBlock.LinesAfter ??= new List<StringSlice>();
-                    var linesBefore = blockProcessor.UseLinesBefore();
-                    rootMostContainerBlock.LinesAfter.AddRange(linesBefore);
-                }
+                ProcessBlocksTrivia(blockProcessor, document);
             }
 
             // At this point the LineIndex is the same as the number of lines in the document
@@ -117,12 +94,15 @@ public static class MarkdownParser
         return text.Replace('\0', CharHelper.ReplacementChar);
     }
 
-    private static void ProcessBlocks(BlockProcessor blockProcessor, LineReader lineReader)
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static void ProcessBlocks(BlockProcessor blockProcessor, string text)
     {
+        var lineReader = new LineReader(text);
+
         while (true)
         {
-            // Get the precise position of the begining of the line
-            var lineText = lineReader.ReadLine();
+            // Get the precise position of the beginning of the line
+            StringSlice lineText = lineReader.ReadLine();
 
             // If this is the end of file and the last line is empty
             if (lineText.Text is null)
@@ -132,9 +112,39 @@ public static class MarkdownParser
 
             blockProcessor.ProcessLine(lineText);
         }
+
         blockProcessor.CloseAll(true);
     }
 
+    private static void ProcessBlocksTrivia(BlockProcessor blockProcessor, MarkdownDocument document)
+    {
+        Block? lastBlock = blockProcessor.LastBlock;
+        if (lastBlock is null && document.Count == 0)
+        {
+            // this means we have unassigned characters
+            var noBlocksFoundBlock = new EmptyBlock(null);
+            List<StringSlice> linesBefore = blockProcessor.UseLinesBefore();
+            noBlocksFoundBlock.LinesAfter = [];
+            if (linesBefore != null)
+            {
+                noBlocksFoundBlock.LinesAfter.AddRange(linesBefore);
+            }
+
+            document.Add(noBlocksFoundBlock);
+        }
+        else if (lastBlock != null && blockProcessor.LinesBefore != null)
+        {
+            // this means we're out of lines, but still have unassigned empty lines.
+            // thus, we'll assign the empty unsassigned lines to the last block
+            // of the document.
+            var rootMostContainerBlock = Block.FindRootMostContainerParent(lastBlock);
+            rootMostContainerBlock.LinesAfter ??= [];
+            var linesBefore = blockProcessor.UseLinesBefore();
+            rootMostContainerBlock.LinesAfter.AddRange(linesBefore);
+        }
+    }
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
     private static void ProcessInlines(InlineProcessor inlineProcessor, MarkdownDocument document)
     {
         // "stackless" processor
@@ -200,16 +210,10 @@ public static class MarkdownParser
         }
     }
 
-    private struct ContainerItem
+    private struct ContainerItem(ContainerBlock container)
     {
-        public ContainerItem(ContainerBlock container)
-        {
-            Container = container;
-            Index = 0;
-        }
+        public readonly ContainerBlock Container = container;
 
-        public readonly ContainerBlock Container;
-
-        public int Index;
+        public int Index = 0;
     }
 }

src/Markdig/Parsers/OrderedListItemParser.cs

@@ -15,7 +15,7 @@ public abstract class OrderedListItemParser : ListItemParser
     /// </summary>
     protected OrderedListItemParser()
     {
-        OrderedDelimiters = new[] { '.', ')' };
+        OrderedDelimiters = ['.', ')'];
     }
 
     /// <summary>

src/Markdig/Parsers/QuoteBlockParser.cs

@@ -18,7 +18,7 @@ public class QuoteBlockParser : BlockParser
     /// </summary>
     public QuoteBlockParser()
     {
-        OpeningCharacters = new[] {'>'};
+        OpeningCharacters = ['>'];
     }
 
     public override BlockState TryOpen(BlockProcessor processor)

src/Markdig/Parsers/ThematicBreakParser.cs

@@ -16,14 +16,14 @@ public class ThematicBreakParser : BlockParser
     /// <summary>
     /// A singleton instance used by other parsers.
     /// </summary>
-    public static readonly ThematicBreakParser Default = new ThematicBreakParser();
+    public static readonly ThematicBreakParser Default = new();
 
     /// <summary>
     /// Initializes a new instance of the <see cref="ThematicBreakParser"/> class.
     /// </summary>
     public ThematicBreakParser()
     {
-        OpeningCharacters = new[] {'-', '_', '*'};
+        OpeningCharacters = ['-', '_', '*'];
     }
 
     public override BlockState TryOpen(BlockProcessor processor)

src/Markdig/Parsers/UnorderedListItemParser.cs

@@ -15,7 +15,7 @@ public class UnorderedListItemParser : ListItemParser
     /// </summary>
     public UnorderedListItemParser()
     {
-        OpeningCharacters = new [] {'-', '+', '*'};
+        OpeningCharacters = ['-', '+', '*'];
     }
 
     public override bool TryParse(BlockProcessor state, char pendingBulletType, out ListInfo result)

src/Markdig/Polyfills/Ascii.cs

@@ -0,0 +1,30 @@
+// Copyright (c) Alexandre Mutel. All rights reserved.
+// This file is licensed under the BSD-Clause 2 license.
+// See the license.txt file in the project root for more information.
+
+#if !NET8_0_OR_GREATER
+
+namespace System.Text;
+
+internal static class Ascii
+{
+    public static bool IsValid(this string value)
+    {
+        return IsValid(value.AsSpan());
+    }
+
+    public static bool IsValid(this ReadOnlySpan<char> value)
+    {
+        for (int i = 0; i < value.Length; i++)
+        {
+            if (value[i] > 127)
+            {
+                return false;
+            }
+        }
+
+        return true;
+    }
+}
+
+#endif

src/Markdig/Polyfills/EncodingExtensions.cs

@@ -0,0 +1,24 @@
+// Copyright (c) Alexandre Mutel. All rights reserved.
+// This file is licensed under the BSD-Clause 2 license.
+// See the license.txt file in the project root for more information.
+
+#if !NETSTANDARD2_1_OR_GREATER
+
+using System.Runtime.InteropServices;
+
+namespace System.Text;
+
+internal static class EncodingExtensions
+{
+    public static unsafe int GetBytes(this Encoding encoding, ReadOnlySpan<char> chars, Span<byte> bytes)
+    {
+        fixed (char* charsPtr = &MemoryMarshal.GetReference(chars))
+        {
+            fixed (byte* bytesPtr = &MemoryMarshal.GetReference(bytes))
+            {
+                return encoding.GetBytes(charsPtr, chars.Length, bytesPtr, bytes.Length);
+            }
+        }
+    }
+}
+#endif

src/Markdig/Polyfills/IndexOfHelpers.cs

@@ -0,0 +1,53 @@
+// Copyright (c) Alexandre Mutel. All rights reserved.
+// This file is licensed under the BSD-Clause 2 license.
+// See the license.txt file in the project root for more information.
+
+#if !NET8_0_OR_GREATER
+
+namespace System;
+
+internal static class IndexOfHelpers
+{
+    public static bool ContainsAnyExcept(this ReadOnlySpan<char> span, char value0, char value1, char value2)
+    {
+        for (int i = 0; i < span.Length; i++)
+        {
+            char c = span[i];
+            if (c != value0 && c != value1 && c != value2)
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+#if !NETSTANDARD2_1_OR_GREATER
+    public static int IndexOfAny(this ReadOnlySpan<char> span, string values)
+    {
+        for (int i = 0; i < span.Length; i++)
+        {
+            char c = span[i];
+
+            foreach (char v in values)
+            {
+                if (c == v)
+                {
+                    return i;
+                }
+            }
+        }
+
+        return -1;
+    }
+#endif
+
+#if !NET6_0_OR_GREATER
+    public static bool Contains<T>(this ReadOnlySpan<T> span, T value) where T : IEquatable<T>
+    {
+        return span.IndexOf(value) >= 0;
+    }
+#endif
+}
+
+#endif

src/Markdig/Polyfills/NullableAttributes.cs

@@ -23,7 +23,7 @@ internal sealed class AllowNullAttribute : Attribute { }
 #if !NET5_0_OR_GREATER
 internal sealed class MemberNotNullAttribute : Attribute
 {
-    public MemberNotNullAttribute(string member) => Members = new[] { member };
+    public MemberNotNullAttribute(string member) => Members = [member];
 
     public MemberNotNullAttribute(params string[] members) => Members = members;
 

src/Markdig/Polyfills/SearchValues.cs

@@ -0,0 +1,137 @@
+// Copyright (c) Alexandre Mutel. All rights reserved.
+// This file is licensed under the BSD-Clause 2 license.
+// See the license.txt file in the project root for more information.
+
+#if !NET8_0_OR_GREATER
+
+using System.Diagnostics;
+using System.Runtime.CompilerServices;
+
+namespace System.Buffers;
+
+internal static class SearchValues
+{
+    public static SearchValues<char> Create(string values) =>
+        Create(values.AsSpan());
+
+    public static SearchValues<char> Create(ReadOnlySpan<char> values) =>
+        new PreNet8CompatSearchValues(values);
+
+    public static int IndexOfAny(this ReadOnlySpan<char> span, SearchValues<char> values) =>
+        values.IndexOfAny(span);
+
+    public static int IndexOfAnyExcept(this ReadOnlySpan<char> span, SearchValues<char> values) =>
+        values.IndexOfAnyExcept(span);
+}
+
+internal abstract class SearchValues<T>
+{
+    public abstract int IndexOfAny(ReadOnlySpan<char> span);
+
+    public abstract int IndexOfAnyExcept(ReadOnlySpan<char> span);
+}
+
+internal sealed class PreNet8CompatSearchValues : SearchValues<char>
+{
+    private readonly BoolVector128 _ascii;
+    private readonly HashSet<char>? _nonAscii;
+
+    public PreNet8CompatSearchValues(ReadOnlySpan<char> values)
+    {
+        foreach (char c in values)
+        {
+            if (c < 128)
+            {
+                _ascii.Set(c);
+            }
+            else
+            {
+                _nonAscii ??= new HashSet<char>();
+                _nonAscii.Add(c);
+            }
+        }
+    }
+
+    public override int IndexOfAny(ReadOnlySpan<char> span)
+    {
+        if (_nonAscii is null)
+        {
+            for (int i = 0; i < span.Length; i++)
+            {
+                char c = span[i];
+
+                if (c < 128 && _ascii[c])
+                {
+                    return i;
+                }
+            }
+        }
+        else
+        {
+            for (int i = 0; i < span.Length; i++)
+            {
+                char c = span[i];
+
+                if (c < 128 ? _ascii[c] : _nonAscii.Contains(c))
+                {
+                    return i;
+                }
+            }
+        }
+
+        return -1;
+    }
+
+    public override int IndexOfAnyExcept(ReadOnlySpan<char> span)
+    {
+        if (_nonAscii is null)
+        {
+            for (int i = 0; i < span.Length; i++)
+            {
+                char c = span[i];
+
+                if (c >= 128 || !_ascii[c])
+                {
+                    return i;
+                }
+            }
+        }
+        else
+        {
+            for (int i = 0; i < span.Length; i++)
+            {
+                char c = span[i];
+
+                if (c < 128 ? !_ascii[c] : !_nonAscii.Contains(c))
+                {
+                    return i;
+                }
+            }
+        }
+
+        return -1;
+    }
+
+    private unsafe struct BoolVector128
+    {
+        private fixed bool _values[128];
+
+        public void Set(char c)
+        {
+            Debug.Assert(c < 128);
+            _values[c] = true;
+        }
+
+        public readonly bool this[uint c]
+        {
+            [MethodImpl(MethodImplOptions.AggressiveInlining)]
+            get
+            {
+                Debug.Assert(c < 128);
+                return _values[c];
+            }
+        }
+    }
+}
+
+#endif

src/Markdig/Renderers/Html/HeadingRenderer.cs

@@ -12,14 +12,14 @@ namespace Markdig.Renderers.Html;
 /// <seealso cref="HtmlObjectRenderer{HeadingBlock}" />
 public class HeadingRenderer : HtmlObjectRenderer<HeadingBlock>
 {
-    private static readonly string[] HeadingTexts = {
+    private static readonly string[] HeadingTexts = [
         "h1",
         "h2",
         "h3",
         "h4",
         "h5",
         "h6",
-    };
+    ];
 
     protected override void Write(HtmlRenderer renderer, HeadingBlock obj)
     {

src/Markdig/Renderers/HtmlRenderer.cs

@@ -2,6 +2,7 @@
 // This file is licensed under the BSD-Clause 2 license. 
 // See the license.txt file in the project root for more information.
 
+using System.Buffers;
 using System.Globalization;
 using System.IO;
 using System.Runtime.CompilerServices;
@@ -20,7 +21,10 @@ namespace Markdig.Renderers;
 /// <seealso cref="TextRendererBase{HtmlRenderer}" />
 public class HtmlRenderer : TextRendererBase<HtmlRenderer>
 {
-    private static readonly char[] s_writeEscapeIndexOfAnyChars = new[] { '<', '>', '&', '"' };
+    private static readonly IdnMapping s_idnMapping = new();
+
+    private static readonly SearchValues<char> s_asciiNonEscapeChars =
+        SearchValues.Create("!#$%()*+,-./0123456789:;=?@ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz");
 
     /// <summary>
     /// Initializes a new instance of the <see cref="HtmlRenderer"/> class.
@@ -140,6 +144,8 @@ public class HtmlRenderer : TextRendererBase<HtmlRenderer>
         return this;
     }
 
+    private static readonly SearchValues<char> s_escapedChars = SearchValues.Create("<>&\"");
+
     /// <summary>
     /// Writes the content escaped for HTML.
     /// </summary>
@@ -149,73 +155,38 @@ public class HtmlRenderer : TextRendererBase<HtmlRenderer>
     {
         if (!content.IsEmpty)
         {
-            int nextIndex = content.IndexOfAny(s_writeEscapeIndexOfAnyChars);
-            if (nextIndex == -1)
+            WriteIndent();
+
+            while (true)
             {
-                Write(content);
-            }
-            else
-            {
-                WriteEscapeSlow(content, softEscape);
+                int indexOfCharToEscape = softEscape
+                    ? content.IndexOfAny('<', '&')
+                    : content.IndexOfAny(s_escapedChars);
+
+                if ((uint)indexOfCharToEscape >= (uint)content.Length)
+                {
+                    WriteRaw(content);
+                    return;
+                }
+
+                WriteRaw(content.Slice(0, indexOfCharToEscape));
+
+                if (EnableHtmlEscape)
+                {
+                    WriteRaw(content[indexOfCharToEscape] switch
+                    {
+                        '<' => "&lt;",
+                        '>' => "&gt;",
+                        '&' => "&amp;",
+                        _ => "&quot;",
+                    });
+                }
+
+                content = content.Slice(indexOfCharToEscape + 1);
             }
         }
     }
 
-    private void WriteEscapeSlow(ReadOnlySpan<char> content, bool softEscape = false)
-    {
-        WriteIndent();
-
-        int previousOffset = 0;
-        for (int i = 0; i < content.Length; i++)
-        {
-            switch (content[i])
-            {
-                case '<':
-                    WriteRaw(content.Slice(previousOffset, i - previousOffset));
-                    if (EnableHtmlEscape)
-                    {
-                        WriteRaw("&lt;");
-                    }
-                    previousOffset = i + 1;
-                    break;
-                case '>':
-                    if (!softEscape)
-                    {
-                        WriteRaw(content.Slice(previousOffset, i - previousOffset));
-                        if (EnableHtmlEscape)
-                        {
-                            WriteRaw("&gt;");
-                        }
-                        previousOffset = i + 1;
-                    }
-                    break;
-                case '&':
-                    WriteRaw(content.Slice(previousOffset, i - previousOffset));
-                    if (EnableHtmlEscape)
-                    {
-                        WriteRaw("&amp;");
-                    }
-                    previousOffset = i + 1;
-                    break;
-                case '"':
-                    if (!softEscape)
-                    {
-                        WriteRaw(content.Slice(previousOffset, i - previousOffset));
-                        if (EnableHtmlEscape)
-                        {
-                            WriteRaw("&quot;");
-                        }
-                        previousOffset = i + 1;
-                    }
-                    break;
-            }
-        }
-
-        WriteRaw(content.Slice(previousOffset));
-    }
-
-    private static readonly IdnMapping IdnMapping = new IdnMapping();
-
     /// <summary>
     /// Writes the URL escaped for HTML.
     /// </summary>
@@ -239,120 +210,107 @@ public class HtmlRenderer : TextRendererBase<HtmlRenderer>
             content = LinkRewriter(content);
         }
 
-        // a://c.d = 7 chars
-        int schemeOffset = content.Length < 7 ? -1 : content.IndexOf("://", StringComparison.Ordinal);
-        if (schemeOffset != -1) // This is an absolute URL
+        if (!Ascii.IsValid(content))
         {
-            schemeOffset += 3; // skip ://
-            WriteEscapeUrl(content, 0, schemeOffset);
-
-            bool idnaEncodeDomain = false;
-            int endOfDomain = schemeOffset;
-            for (; endOfDomain < content.Length; endOfDomain++)
+            int schemeOffset = content.IndexOf("://", StringComparison.Ordinal);
+            if (schemeOffset > 0) // This is an absolute URL
             {
-                char c = content[endOfDomain];
-                if (c == '/' || c == '?' || c == '#' || c == ':') // End of domain part
-                {
-                    break;
-                }
-                if (c > 127)
-                {
-                    idnaEncodeDomain = true;
-                }
-            }
+                schemeOffset += 3; // skip ://
 
-            if (idnaEncodeDomain)
-            {
-                string domainName;
+                int domainLength = content.AsSpan(schemeOffset).IndexOfAny("/?#:");
+                if (domainLength < 0)
+                {
+                    domainLength = content.Length - schemeOffset;
+                }
+
+                string? domainName = null;
 
                 try
                 {
-                    domainName = IdnMapping.GetAscii(content, schemeOffset, endOfDomain - schemeOffset);
+                    domainName = s_idnMapping.GetAscii(content, schemeOffset, domainLength);
                 }
-                catch
+                catch { }
+
+                if (domainName is not null)
                 {
-                    // Not a valid IDN, fallback to non-punycode encoding
-                    WriteEscapeUrl(content, schemeOffset, content.Length);
+                    WriteEscapeUrlCore(content.AsSpan(0, schemeOffset));
+                    WriteEscapeUrlCore(domainName.AsSpan());
+                    WriteEscapeUrlCore(content.AsSpan(schemeOffset + domainLength));
                     return this;
                 }
 
-                // Escape the characters (see Commonmark example 327 and think of it with a non-ascii symbol)
-                int previousPosition = 0;
-                for (int i = 0; i < domainName.Length; i++)
-                {
-                    var escape = HtmlHelper.EscapeUrlCharacter(domainName[i]);
-                    if (escape != null)
-                    {
-                        Write(domainName, previousPosition, i - previousPosition);
-                        previousPosition = i + 1;
-                        Write(escape);
-                    }
-                }
-                Write(domainName, previousPosition, domainName.Length - previousPosition);
-                WriteEscapeUrl(content, endOfDomain, content.Length);
+                // Not a valid IDN, fallback to non-punycode encoding
             }
-            else
-            {
-                WriteEscapeUrl(content, schemeOffset, content.Length);
-            }
-        }
-        else // This is a relative URL
-        {
-            WriteEscapeUrl(content, 0, content.Length);
         }
 
+        WriteEscapeUrlCore(content.AsSpan());
         return this;
     }
 
-    private void WriteEscapeUrl(string content, int start, int length)
+    private void WriteEscapeUrlCore(ReadOnlySpan<char> content)
     {
-        int previousPosition = start;
-        for (var i = previousPosition; i < length; i++)
+        WriteIndent();
+
+        while (true)
         {
-            var c = content[i];
+            int i = content.IndexOfAnyExcept(s_asciiNonEscapeChars);
+
+            if ((uint)i >= (uint)content.Length)
+            {
+                WriteRaw(content);
+                break;
+            }
+
+            WriteRaw(content.Slice(0, i));
+
+            char c = content[i];
 
             if (c < 128)
             {
-                var escape = HtmlHelper.EscapeUrlCharacter(c);
-                if (escape != null)
-                {
-                    Write(content, previousPosition, i - previousPosition);
-                    previousPosition = i + 1;
-                    Write(escape);
-                }
+                WriteRaw(HtmlHelper.EscapeUrlCharacter(c));
+            }
+            else if (UseNonAsciiNoEscape)
+            {
+                // Special case for Edge/IE workaround for MarkdownEditor, don't escape non-ASCII chars to make image links working
+                WriteRaw(c);
             }
             else
             {
-                Write(content, previousPosition, i - previousPosition);
-                previousPosition = i + 1;
-
-                // Special case for Edge/IE workaround for MarkdownEditor, don't escape non-ASCII chars to make image links working
-                if (UseNonAsciiNoEscape)
-                {
-                    Write(c);
-                }
-                else
-                {
-                    byte[] bytes;
-                    if (c >= '\ud800' && c <= '\udfff' && previousPosition < length)
-                    {
-                        bytes = Encoding.UTF8.GetBytes(new[] { c, content[previousPosition] });
-                        // Skip next char as it is decoded above
-                        i++;
-                        previousPosition = i + 1;
-                    }
-                    else
-                    {
-                        bytes = Encoding.UTF8.GetBytes(new[] { c });
-                    }
-                    for (var j = 0; j < bytes.Length; j++)
-                    {
-                        Write($"%{bytes[j]:X2}");
-                    }
-                }
+                i = WriteEscapedUtf8Bytes(this, content, c, i);
             }
+
+            content = content.Slice(i + 1);
+        }
+
+        static int WriteEscapedUtf8Bytes(HtmlRenderer renderer, ReadOnlySpan<char> content, char c, int i)
+        {
+            scoped ReadOnlySpan<char> chars;
+
+            if (CharHelper.IsHighSurrogate(c) && (uint)(i + 1) < (uint)content.Length)
+            {
+                chars = stackalloc char[] { c, content[i + 1] };
+                i++;
+            }
+            else
+            {
+                chars = stackalloc char[] { c };
+            }
+
+            Span<byte> utf8Buffer = stackalloc byte[4];
+            int utf8Length = Encoding.UTF8.GetBytes(chars, utf8Buffer);
+            utf8Buffer = utf8Buffer.Slice(0, utf8Length);
+
+            Span<char> escapedBuffer = stackalloc char[3];
+            escapedBuffer[0] = '%';
+
+            foreach (byte b in utf8Buffer)
+            {
+                HexConverter.ToCharsBuffer(b, escapedBuffer, startingIndex: 1);
+                renderer.WriteRaw(escapedBuffer);
+            }
+
+            return i;
         }
-        Write(content, previousPosition, length - previousPosition);
     }
 
     /// <summary>

src/Markdig/Renderers/Normalize/CodeBlockRenderer.cs

@@ -18,9 +18,9 @@ public class CodeBlockRenderer : NormalizeObjectRenderer<CodeBlock>
     {
         if (obj is FencedCodeBlock fencedCodeBlock)
         {
-            var fencedCharCount = Math.Min(fencedCodeBlock.OpeningFencedCharCount, fencedCodeBlock.ClosingFencedCharCount);
-            var opening = new string(fencedCodeBlock.FencedChar, fencedCharCount);
-            renderer.Write(opening);
+            int fencedCharCount = Math.Min(fencedCodeBlock.OpeningFencedCharCount, fencedCodeBlock.ClosingFencedCharCount);
+
+            renderer.Write(fencedCodeBlock.FencedChar, fencedCharCount);
             if (fencedCodeBlock.Info != null)
             {
                 renderer.Write(fencedCodeBlock.Info);
@@ -41,7 +41,7 @@ public class CodeBlockRenderer : NormalizeObjectRenderer<CodeBlock>
             renderer.WriteLine();
 
             renderer.WriteLeafRawLines(obj, true);
-            renderer.Write(opening);
+            renderer.Write(fencedCodeBlock.FencedChar, fencedCharCount);
         }
         else
         {

src/Markdig/Renderers/Normalize/HeadingRenderer.cs

@@ -12,22 +12,27 @@ namespace Markdig.Renderers.Normalize;
 /// <seealso cref="NormalizeObjectRenderer{HeadingBlock}" />
 public class HeadingRenderer : NormalizeObjectRenderer<HeadingBlock>
 {
-    private static readonly string[] HeadingTexts = {
+    private static readonly string[] HeadingTexts = [
         "#",
         "##",
         "###",
         "####",
         "#####",
         "######",
-    };
+    ];
 
     protected override void Write(NormalizeRenderer renderer, HeadingBlock obj)
-    {
-        var headingText = obj.Level > 0 && obj.Level <= 6
-            ? HeadingTexts[obj.Level - 1]
-            : new string('#', obj.Level);
+    {        
+        if (obj.Level is > 0 and <= 6)
+        {
+            renderer.Write(HeadingTexts[obj.Level - 1]);
+        }
+        else
+        {
+            renderer.Write('#', obj.Level);            
+        }        
 
-        renderer.Write(headingText).Write(' ');
+        renderer.Write(' ');
         renderer.WriteLeafInline(obj);
 
         renderer.FinishBlock(renderer.Options.EmptyLineAfterHeading);

src/Markdig/Renderers/Normalize/Inlines/CodeInlineRenderer.cs

@@ -31,8 +31,8 @@ public class CodeInlineRenderer : NormalizeObjectRenderer<CodeInline>
             if (delimiterCount < count)
                 delimiterCount = count;
         }
-        var delimiterRun = new string(obj.Delimiter, delimiterCount + 1);
-        renderer.Write(delimiterRun);
+
+        renderer.Write(obj.Delimiter, delimiterCount + 1);
         if (content.Length != 0)
         {
             if (content[0] == obj.Delimiter)
@@ -49,6 +49,6 @@ public class CodeInlineRenderer : NormalizeObjectRenderer<CodeInline>
         {
             renderer.Write(' ');
         }
-        renderer.Write(delimiterRun);
+        renderer.Write(obj.Delimiter, delimiterCount + 1);
     }
 }

src/Markdig/Renderers/Normalize/Inlines/EmphasisInlineRenderer.cs

@@ -14,9 +14,8 @@ public class EmphasisInlineRenderer : NormalizeObjectRenderer<EmphasisInline>
 {
     protected override void Write(NormalizeRenderer renderer, EmphasisInline obj)
     {
-        var emphasisText = new string(obj.DelimiterChar, obj.DelimiterCount);
-        renderer.Write(emphasisText);
+        renderer.Write(obj.DelimiterChar, obj.DelimiterCount);
         renderer.WriteChildren(obj);
-        renderer.Write(emphasisText);
+        renderer.Write(obj.DelimiterChar, obj.DelimiterCount);
     }
 }

src/Markdig/Renderers/RendererBase.cs

@@ -3,7 +3,7 @@
 // See the license.txt file in the project root for more information.
 
 using System.Runtime.CompilerServices;
-
+using System.Runtime.InteropServices;
 using Markdig.Helpers;
 using Markdig.Syntax;
 using Markdig.Syntax.Inlines;
@@ -16,31 +16,64 @@ namespace Markdig.Renderers;
 /// <seealso cref="IMarkdownRenderer" />
 public abstract class RendererBase : IMarkdownRenderer
 {
-    private readonly Dictionary<KeyWrapper, IMarkdownObjectRenderer?> _renderersPerType = new();
+    private const int SubTableCount = 32;
+
+    private readonly struct RendererEntry
+    {
+        public readonly IntPtr Key;
+        public readonly IMarkdownObjectRenderer? Renderer;
+
+        public RendererEntry(IntPtr key, IMarkdownObjectRenderer? renderer)
+        {
+            Key = key;
+            Renderer = renderer;
+        }
+    }
+
+    private readonly RendererEntry[][] _renderersPerType;
+
     internal int _childrenDepth = 0;
 
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private static IntPtr GetKeyForType(MarkdownObject obj) => Type.GetTypeHandle(obj).Value;
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private static int SubTableIndex(IntPtr key) => (int)((((ulong)key) / 64) & (SubTableCount - 1));
+
     /// <summary>
     /// Initializes a new instance of the <see cref="RendererBase"/> class.
     /// </summary>
-    protected RendererBase() { }
+    protected RendererBase()
+    {
+        var entries = _renderersPerType = new RendererEntry[SubTableCount][];
+        for (int i = 0; i < entries.Length; i++)
+        {
+            entries[i] ??= [];
+        }
+    }
 
+    [MethodImpl(MethodImplOptions.NoInlining)]
     private IMarkdownObjectRenderer? GetRendererInstance(MarkdownObject obj)
     {
-        KeyWrapper key = GetKeyForType(obj);
         Type objectType = obj.GetType();
+        IMarkdownObjectRenderer? renderer = null;
 
-        for (int i = 0; i < ObjectRenderers.Count; i++)
+        foreach (var potentialRenderer in ObjectRenderers)
         {
-            var renderer = ObjectRenderers[i];
-            if (renderer.Accept(this, objectType))
+            if (potentialRenderer.Accept(this, objectType))
             {
-                _renderersPerType[key] = renderer;
-                return renderer;
+                renderer = potentialRenderer;
+                break;
             }
         }
 
-        _renderersPerType[key] = null;
-        return null;
+        IntPtr key = GetKeyForType(obj);
+
+        ref RendererEntry[] entries = ref _renderersPerType[SubTableIndex(key)];
+        Array.Resize(ref entries, entries.Length + 1);
+        entries[entries.Length - 1] = new RendererEntry(key, renderer);
+
+        return renderer;
     }
 
     public ObjectRendererCollection ObjectRenderers { get; } = new();
@@ -77,12 +110,11 @@ public abstract class RendererBase : IMarkdownRenderer
         bool saveIsFirstInContainer = IsFirstInContainer;
         bool saveIsLastInContainer = IsLastInContainer;
 
-        var children = containerBlock;
-        for (int i = 0; i < children.Count; i++)
+        for (int i = 0; i < containerBlock.Count; i++)
         {
             IsFirstInContainer = i == 0;
-            IsLastInContainer = i + 1 == children.Count;
-            Write(children[i]);
+            IsLastInContainer = i + 1 == containerBlock.Count;
+            Write(containerBlock[i]);
         }
 
         IsFirstInContainer = saveIsFirstInContainer;
@@ -140,11 +172,27 @@ public abstract class RendererBase : IMarkdownRenderer
         // Calls before writing an object
         ObjectWriteBefore?.Invoke(this, obj);
 
-        if (!_renderersPerType.TryGetValue(GetKeyForType(obj), out IMarkdownObjectRenderer? renderer))
+        IMarkdownObjectRenderer? renderer = null;
+        IntPtr key = GetKeyForType(obj);
+
+#if NETFRAMEWORK || NETSTANDARD
+        RendererEntry[] renderers = _renderersPerType[SubTableIndex(key)];
+#else
+        RendererEntry[] renderers = Unsafe.Add(ref MemoryMarshal.GetArrayDataReference(_renderersPerType), SubTableIndex(key));
+#endif
+
+        foreach (RendererEntry entry in renderers)
         {
-            renderer = GetRendererInstance(obj);
+            if (key == entry.Key)
+            {
+                renderer = entry.Renderer;
+                goto Render;
+            }
         }
 
+        renderer = GetRendererInstance(obj);
+
+    Render:
         if (renderer is not null)
         {
             renderer.Write(this, obj);
@@ -161,24 +209,4 @@ public abstract class RendererBase : IMarkdownRenderer
         // Calls after writing an object
         ObjectWriteAfter?.Invoke(this, obj);
     }
-
-    [MethodImpl(MethodImplOptions.AggressiveInlining)]
-    private static KeyWrapper GetKeyForType(MarkdownObject obj)
-    {
-        IntPtr typeHandle = Type.GetTypeHandle(obj).Value;
-        return new KeyWrapper(typeHandle);
-    }
-
-    private readonly struct KeyWrapper : IEquatable<KeyWrapper>
-    {
-        public readonly IntPtr Key;
-
-        public KeyWrapper(IntPtr key) => Key = key;
-
-        public bool Equals(KeyWrapper other) => Key == other.Key;
-
-        public override int GetHashCode() => Key.GetHashCode();
-
-        public override bool Equals(object? obj) => throw new NotImplementedException();
-    }
 }

src/Markdig/Renderers/Roundtrip/CodeBlockRenderer.cs

@@ -19,8 +19,7 @@ public class CodeBlockRenderer : RoundtripObjectRenderer<CodeBlock>
         if (obj is FencedCodeBlock fencedCodeBlock)
         {
             renderer.Write(obj.TriviaBefore);
-            var opening = new string(fencedCodeBlock.FencedChar, fencedCodeBlock.OpeningFencedCharCount);
-            renderer.Write(opening);
+            renderer.Write(fencedCodeBlock.FencedChar, fencedCodeBlock.OpeningFencedCharCount);
 
             if (!fencedCodeBlock.TriviaAfterFencedChar.IsEmpty)
             {
@@ -56,9 +55,8 @@ public class CodeBlockRenderer : RoundtripObjectRenderer<CodeBlock>
             renderer.WriteLeafRawLines(obj);
 
             renderer.Write(fencedCodeBlock.TriviaBeforeClosingFence);
-            var closing = new string(fencedCodeBlock.FencedChar, fencedCodeBlock.ClosingFencedCharCount);
-            renderer.Write(closing);
-            if (!string.IsNullOrEmpty(closing))
+            renderer.Write(fencedCodeBlock.FencedChar, fencedCodeBlock.ClosingFencedCharCount);
+            if (fencedCodeBlock.ClosingFencedCharCount > 0)
             {
                 // See example 207: "> ```\nfoo\n```"
                 renderer.WriteLine(obj.NewLine);

src/Markdig/Renderers/Roundtrip/HeadingRenderer.cs

@@ -12,14 +12,14 @@ namespace Markdig.Renderers.Roundtrip;
 /// <seealso cref="RoundtripObjectRenderer{HeadingBlock}" />
 public class HeadingRenderer : RoundtripObjectRenderer<HeadingBlock>
 {
-    private static readonly string[] HeadingTexts = {
+    private static readonly string[] HeadingTexts = [
         "#",
         "##",
         "###",
         "####",
         "#####",
         "######",
-    };
+    ];
 
     protected override void Write(RoundtripRenderer renderer, HeadingBlock obj)
     {
@@ -28,12 +28,11 @@ public class HeadingRenderer : RoundtripObjectRenderer<HeadingBlock>
             renderer.RenderLinesBefore(obj);
 
             var headingChar = obj.Level == 1 ? '=' : '-';
-            var line = new string(headingChar, obj.HeaderCharCount);
 
             renderer.WriteLeafInline(obj);
             renderer.WriteLine(obj.SetextNewline);
             renderer.Write(obj.TriviaBefore);
-            renderer.Write(line);
+            renderer.Write(headingChar, obj.HeaderCharCount);
             renderer.WriteLine(obj.NewLine);
             renderer.Write(obj.TriviaAfter);
 
@@ -43,12 +42,17 @@ public class HeadingRenderer : RoundtripObjectRenderer<HeadingBlock>
         {
             renderer.RenderLinesBefore(obj);
 
-            var headingText = obj.Level > 0 && obj.Level <= 6
-                ? HeadingTexts[obj.Level - 1]
-                : new string('#', obj.Level);
-
             renderer.Write(obj.TriviaBefore);
-            renderer.Write(headingText);
+
+            if (obj.Level is > 0 and <= 6)
+            {
+                renderer.Write(HeadingTexts[obj.Level - 1]);
+            }
+            else
+            {
+                renderer.Write('#', obj.Level);
+            }
+
             renderer.Write(obj.TriviaAfterAtxHeaderChar);
             renderer.WriteLeafInline(obj);
             renderer.Write(obj.TriviaAfter);

src/Markdig/Renderers/Roundtrip/Inlines/CodeInlineRenderer.cs

@@ -14,12 +14,11 @@ public class CodeInlineRenderer : RoundtripObjectRenderer<CodeInline>
 {
     protected override void Write(RoundtripRenderer renderer, CodeInline obj)
     {
-        var delimiterRun = new string(obj.Delimiter, obj.DelimiterCount);
-        renderer.Write(delimiterRun);
+        renderer.Write(obj.Delimiter, obj.DelimiterCount);
         if (!obj.ContentSpan.IsEmpty)
         {
             renderer.Write(obj.ContentWithTrivia);
         }
-        renderer.Write(delimiterRun);
+        renderer.Write(obj.Delimiter, obj.DelimiterCount);
     }
 }

src/Markdig/Renderers/Roundtrip/Inlines/EmphasisInlineRenderer.cs

@@ -14,9 +14,8 @@ public class EmphasisInlineRenderer : RoundtripObjectRenderer<EmphasisInline>
 {
     protected override void Write(RoundtripRenderer renderer, EmphasisInline obj)
     {
-        var emphasisText = new string(obj.DelimiterChar, obj.DelimiterCount);
-        renderer.Write(emphasisText);
+        renderer.Write(obj.DelimiterChar, obj.DelimiterCount);
         renderer.WriteChildren(obj);
-        renderer.Write(emphasisText);
+        renderer.Write(obj.DelimiterChar, obj.DelimiterCount);
     }
 }

src/Markdig/Renderers/TextRendererBase.cs

@@ -211,6 +211,25 @@ public abstract class TextRendererBase<T> : TextRendererBase where T : TextRende
         return (T)this;
     }
 
+    /// <summary>
+    /// Writes the specified char repeated a specified number of times.
+    /// </summary>
+    /// <param name="c">The char to write.</param>
+    /// <param name="count">The number of times to write the char.</param>
+    /// <returns>This instance</returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    internal T Write(char c, int count)
+    {
+        WriteIndent();        
+        
+        for (int i = 0; i < count; i++)
+        {
+            Writer.Write(c);
+        }        
+
+        return (T)this;
+    }
+
     /// <summary>
     /// Writes the specified slice.
     /// </summary>

src/Markdig/Syntax/CodeBlock.cs

@@ -21,7 +21,7 @@ public class CodeBlock : LeafBlock
     }
 
     private List<CodeBlockLine>? _codeBlockLines;
-    public List<CodeBlockLine> CodeBlockLines => _codeBlockLines ??= new();
+    public List<CodeBlockLine> CodeBlockLines => _codeBlockLines ??= [];
 
     /// <summary>
     /// Initializes a new instance of the <see cref="CodeBlock"/> class.

src/Markdig/Syntax/ContainerBlock.cs

@@ -27,7 +27,7 @@ public abstract class ContainerBlock : Block, IList<Block>, IReadOnlyList<Block>
     /// <param name="parser">The parser used to create this block.</param>
     protected ContainerBlock(BlockParser? parser) : base(parser)
     {
-        _children = Array.Empty<BlockWrapper>();
+        _children = [];
         SetTypeKind(isInline: false, isContainer: true);
     }
 
@@ -301,14 +301,9 @@ public abstract class ContainerBlock : Block, IList<Block>, IReadOnlyList<Block>
 
     #endregion
 
-    private sealed class BlockComparisonWrapper : IComparer<BlockWrapper>
+    private sealed class BlockComparisonWrapper(Comparison<Block> comparison) : IComparer<BlockWrapper>
     {
-        private readonly Comparison<Block> _comparison;
-
-        public BlockComparisonWrapper(Comparison<Block> comparison)
-        {
-            _comparison = comparison;
-        }
+        private readonly Comparison<Block> _comparison = comparison;
 
         public int Compare(BlockWrapper x, BlockWrapper y)
         {
@@ -316,14 +311,9 @@ public abstract class ContainerBlock : Block, IList<Block>, IReadOnlyList<Block>
         }
     }
 
-    private sealed class BlockComparerWrapper : IComparer<BlockWrapper>
+    private sealed class BlockComparerWrapper(IComparer<Block> comparer) : IComparer<BlockWrapper>
     {
-        private readonly IComparer<Block> _comparer;
-
-        public BlockComparerWrapper(IComparer<Block> comparer)
-        {
-            _comparer = comparer;
-        }
+        private readonly IComparer<Block> _comparer = comparer;
 
         public int Compare(BlockWrapper x, BlockWrapper y)
         {

src/Markdig/Syntax/Inlines/ContainerInline.cs

@@ -16,7 +16,7 @@ namespace Markdig.Syntax.Inlines;
 /// <seealso cref="Inline" />
 public class ContainerInline : Inline, IEnumerable<Inline>
 {
-    public ContainerInline()
+    public ContainerInline() : base(dummySkipTypeKind: true)
     {
         SetTypeKind(isInline: true, isContainer: true);
     }

src/Markdig/Syntax/Inlines/EmphasisDelimiterInline.cs

@@ -1,5 +1,5 @@
 // Copyright (c) Alexandre Mutel. All rights reserved.
-// This file is licensed under the BSD-Clause 2 license. 
+// This file is licensed under the BSD-Clause 2 license.
 // See the license.txt file in the project root for more information.
 
 using Markdig.Helpers;
@@ -27,6 +27,24 @@ public class EmphasisDelimiterInline : DelimiterInline
 
         Descriptor = descriptor;
         DelimiterChar = descriptor.Character;
+        Content = new StringSlice(ToLiteral());
+    }
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="EmphasisDelimiterInline" /> class.
+    /// </summary>
+    /// <param name="parser">The parser.</param>
+    /// <param name="descriptor">The descriptor.</param>
+    /// <param name="content">The content.</param>
+    /// <exception cref="ArgumentNullException"></exception>
+    internal EmphasisDelimiterInline(InlineParser parser, EmphasisDescriptor descriptor, StringSlice content) : base(parser)
+    {
+        if (descriptor is null)
+            ThrowHelper.ArgumentNullException(nameof(descriptor));
+
+        Descriptor = descriptor;
+        DelimiterChar = descriptor.Character;
+        Content = content;
     }
 
     /// <summary>
@@ -44,16 +62,35 @@ public class EmphasisDelimiterInline : DelimiterInline
     /// </summary>
     public int DelimiterCount { get; set; }
 
+    /// <summary>
+    /// The content as a <see cref="StringSlice"/>.
+    /// </summary>
+    public StringSlice Content;
+
     public override string ToLiteral()
     {
-        return DelimiterCount > 0 ? new string(DelimiterChar, DelimiterCount) : string.Empty;
+        if (DelimiterCount == 1)
+        {
+            return DelimiterChar switch
+            {
+                '*' => "*",
+                '_' => "_",
+                '~' => "~",
+                '^' => "^",
+                '+' => "+",
+                '=' => "=",
+                _ => DelimiterChar.ToString()
+            };
+        }
+
+        return new string(DelimiterChar, DelimiterCount);
     }
 
     public LiteralInline AsLiteralInline()
     {
         return new LiteralInline()
         {
-            Content = new StringSlice(ToLiteral()),
+            Content = Content,
             IsClosed = true,
             Span = Span,
             Line = Line,

src/Markdig/Syntax/Inlines/Inline.cs

@@ -20,6 +20,8 @@ public abstract class Inline : MarkdownObject, IInline
         SetTypeKind(isInline: true, isContainer: false);
     }
 
+    private protected Inline(bool dummySkipTypeKind) { }
+
     /// <summary>
     /// Gets the parent container of this inline.
     /// </summary>

src/Markdig/Syntax/MarkdownObject.cs

@@ -2,6 +2,7 @@
 // This file is licensed under the BSD-Clause 2 license. 
 // See the license.txt file in the project root for more information.
 
+using System.Diagnostics;
 using System.Runtime.CompilerServices;
 
 using Markdig.Helpers;
@@ -36,7 +37,8 @@ public abstract class MarkdownObject : IMarkdownObject
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     private protected void SetTypeKind(bool isInline, bool isContainer)
     {
-        _lineBits |= (isInline ? IsInlineMask : 0) | (isContainer ? IsContainerMask : 0);
+        Debug.Assert(_lineBits == 0);
+        _lineBits = (isInline ? IsInlineMask : 0) | (isContainer ? IsContainerMask : 0);
     }
 
     private protected bool IsClosedInternal
@@ -153,16 +155,10 @@ public abstract class MarkdownObject : IMarkdownObject
 
     private class DataEntriesAndTrivia
     {
-        private struct DataEntry
+        private struct DataEntry(object key, object value)
         {
-            public readonly object Key;
-            public object Value;
-
-            public DataEntry(object key, object value)
-            {
-                Key = key;
-                Value = value;
-            }
+            public readonly object Key = key;
+            public object Value = value;
         }
 
         private DataEntry[]? _entries;

src/Markdig/Syntax/QuoteBlock.cs

@@ -42,7 +42,7 @@ public class QuoteBlock : ContainerBlock
 public class QuoteBlockLine
 {
     /// <summary>
-    /// Gets or sets trivia occuring before the first quote character.
+    /// Gets or sets trivia occurring before the first quote character.
     /// </summary>
     public StringSlice TriviaBefore { get; set; }
 

src/Markdig/Syntax/SourceSpan.cs

@@ -37,26 +37,26 @@ public struct SourceSpan : IEquatable<SourceSpan>
     /// <summary>
     /// Gets the character length of this element within the original source code.
     /// </summary>
-    public int Length => End - Start + 1;
+    public readonly int Length => End - Start + 1;
 
-    public bool IsEmpty => Start > End;
+    public readonly bool IsEmpty => Start > End;
 
     public SourceSpan MoveForward(int count)
     {
         return new SourceSpan(Start + count, End + count);
     }
 
-    public bool Equals(SourceSpan other)
+    public readonly bool Equals(SourceSpan other)
     {
         return Start == other.Start && End == other.End;
     }
 
-    public override bool Equals(object? obj)
+    public override readonly bool Equals(object? obj)
     {
         return obj is SourceSpan sourceSpan && Equals(sourceSpan);
     }
 
-    public override int GetHashCode()
+    public override readonly int GetHashCode()
     {
         unchecked
         {
@@ -74,7 +74,7 @@ public struct SourceSpan : IEquatable<SourceSpan>
         return !left.Equals(right);
     }
 
-    public override string ToString()
+    public override readonly string ToString()
     {
         return $"{Start}-{End}";
     }

src/SpecFileGen/SpecFileGen.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <IsPackable>false</IsPackable>
   </PropertyGroup>

src/UnicodeNormDApp/UnicodeNormDApp.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net6.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <IsPackable>false</IsPackable>
     <ImplicitUsings>enable</ImplicitUsings>
   </PropertyGroup>

src/global.json

@@ -1,6 +1,6 @@
 {
   "sdk": {
-    "version": "6.0.100",
+    "version": "8.0.100",
     "rollForward": "latestMajor",
     "allowPrerelease": false
   }