Add support for lists in markdown

DiscordChatExporter.Core/Exporting/HtmlMarkdownVisitor.cs

@@ -25,59 +25,59 @@ internal partial class HtmlMarkdownVisitor : MarkdownVisitor
         _isJumbo = isJumbo;
     }
 
-    protected override async ValueTask<MarkdownNode> VisitTextAsync(
+    protected override ValueTask VisitTextAsync(
         TextNode text,
         CancellationToken cancellationToken = default)
     {
         _buffer.Append(HtmlEncode(text.Text));
-        return await base.VisitTextAsync(text, cancellationToken);
+        return default;
     }
 
-    protected override async ValueTask<MarkdownNode> VisitFormattingAsync(
+    protected override async ValueTask VisitFormattingAsync(
         FormattingNode formatting,
         CancellationToken cancellationToken = default)
     {
         var (openingTag, closingTag) = formatting.Kind switch
         {
             FormattingKind.Bold => (
-                // language=HTML
+                // lang=html
                 "<strong>",
-                // language=HTML
+                // lang=html
                 "</strong>"
             ),
 
             FormattingKind.Italic => (
-                // language=HTML
+                // lang=html
                 "<em>",
-                // language=HTML
+                // lang=html
                 "</em>"
             ),
 
             FormattingKind.Underline => (
-                // language=HTML
+                // lang=html
                 "<u>",
-                // language=HTML
+                // lang=html
                 "</u>"
             ),
 
             FormattingKind.Strikethrough => (
-                // language=HTML
+                // lang=html
                 "<s>",
-                // language=HTML
+                // lang=html
                 "</s>"
             ),
 
             FormattingKind.Spoiler => (
-                // language=HTML
+                // lang=html
                 """<span class="chatlog__markdown-spoiler chatlog__markdown-spoiler--hidden" onclick="showSpoiler(event, this)">""",
-                // language=HTML
+                // lang=html
                 """</span>"""
             ),
 
             FormattingKind.Quote => (
-                // language=HTML
+                // lang=html
                 """<div class="chatlog__markdown-quote"><div class="chatlog__markdown-quote-border"></div><div class="chatlog__markdown-quote-content">""",
-                // language=HTML
+                // lang=html
                 """</div></div>"""
             ),
 
@@ -85,13 +85,11 @@ internal partial class HtmlMarkdownVisitor : MarkdownVisitor
         };
 
         _buffer.Append(openingTag);
-        var result = await base.VisitFormattingAsync(formatting, cancellationToken);
+        await VisitAsync(formatting.Children, cancellationToken);
         _buffer.Append(closingTag);
-
-        return result;
     }
 
-    protected override async ValueTask<MarkdownNode> VisitHeaderAsync(
+    protected override async ValueTask VisitHeaderAsync(
         HeaderNode header,
         CancellationToken cancellationToken = default)
     {
@@ -100,31 +98,63 @@ internal partial class HtmlMarkdownVisitor : MarkdownVisitor
             $"<h{header.Level}>"
         );
 
-        var result = await base.VisitHeaderAsync(header, cancellationToken);
+        await VisitAsync(header.Children, cancellationToken);
 
         _buffer.Append(
             // lang=html
             $"</h{header.Level}>"
         );
-
-        return result;
     }
 
-    protected override async ValueTask<MarkdownNode> VisitInlineCodeBlockAsync(
+    protected override async ValueTask VisitListAsync(
+        ListNode list,
+        CancellationToken cancellationToken = default)
+    {
+        _buffer.Append(
+            // lang=html
+            "<ul>"
+        );
+
+        await VisitAsync(list.Items, cancellationToken);
+
+        _buffer.Append(
+            // lang=html
+            "</ul>"
+        );
+    }
+
+    protected override async ValueTask VisitListItemAsync(
+        ListItemNode listItem,
+        CancellationToken cancellationToken = default)
+    {
+        _buffer.Append(
+            // lang=html
+            "<li>"
+        );
+
+        await VisitAsync(listItem.Children, cancellationToken);
+
+        _buffer.Append(
+            // lang=html
+            "</li>"
+        );
+    }
+
+    protected override ValueTask VisitInlineCodeBlockAsync(
         InlineCodeBlockNode inlineCodeBlock,
         CancellationToken cancellationToken = default)
     {
         _buffer.Append(
-            // language=HTML
+            // lang=html
             $"""
             <code class="chatlog__markdown-pre chatlog__markdown-pre--inline">{HtmlEncode(inlineCodeBlock.Code)}</code>
             """
         );
 
-        return await base.VisitInlineCodeBlockAsync(inlineCodeBlock, cancellationToken);
+        return default;
     }
 
-    protected override async ValueTask<MarkdownNode> VisitMultiLineCodeBlockAsync(
+    protected override ValueTask VisitMultiLineCodeBlockAsync(
         MultiLineCodeBlockNode multiLineCodeBlock,
         CancellationToken cancellationToken = default)
     {
@@ -133,16 +163,16 @@ internal partial class HtmlMarkdownVisitor : MarkdownVisitor
             : "nohighlight";
 
         _buffer.Append(
-            // language=HTML
+            // lang=html
             $"""
             <code class="chatlog__markdown-pre chatlog__markdown-pre--multiline {highlightClass}">{HtmlEncode(multiLineCodeBlock.Code)}</code>
             """
         );
 
-        return await base.VisitMultiLineCodeBlockAsync(multiLineCodeBlock, cancellationToken);
+        return default;
     }
 
-    protected override async ValueTask<MarkdownNode> VisitLinkAsync(
+    protected override async ValueTask VisitLinkAsync(
         LinkNode link,
         CancellationToken cancellationToken = default)
     {
@@ -154,21 +184,21 @@ internal partial class HtmlMarkdownVisitor : MarkdownVisitor
 
         _buffer.Append(
             !string.IsNullOrWhiteSpace(linkedMessageId)
-                // language=HTML
+                // lang=html
                 ? $"""<a href="{HtmlEncode(link.Url)}" onclick="scrollToMessage(event, '{linkedMessageId}')">"""
-                // language=HTML
+                // lang=html
                 : $"""<a href="{HtmlEncode(link.Url)}">"""
         );
 
-        var result = await base.VisitLinkAsync(link, cancellationToken);
+        await VisitAsync(link.Children, cancellationToken);
 
-        // language=HTML
+        _buffer.Append(
-        _buffer.Append("</a>");
+            // lang=html
-
+            "</a>"
-        return result;
+        );
     }
 
-    protected override async ValueTask<MarkdownNode> VisitEmojiAsync(
+    protected override async ValueTask VisitEmojiAsync(
         EmojiNode emoji,
         CancellationToken cancellationToken = default)
     {
@@ -176,7 +206,7 @@ internal partial class HtmlMarkdownVisitor : MarkdownVisitor
         var jumboClass = _isJumbo ? "chatlog__emoji--large" : "";
 
         _buffer.Append(
-            // language=HTML
+            // lang=html
             $"""
             <img
                 loading="lazy"
@@ -186,18 +216,15 @@ internal partial class HtmlMarkdownVisitor : MarkdownVisitor
                 src="{await _context.ResolveAssetUrlAsync(emojiImageUrl, cancellationToken)}">
             """
         );
-
-        return await base.VisitEmojiAsync(emoji, cancellationToken);
     }
 
-    protected override async ValueTask<MarkdownNode> VisitMentionAsync(
+    protected override async ValueTask VisitMentionAsync(MentionNode mention,
-        MentionNode mention,
         CancellationToken cancellationToken = default)
     {
         if (mention.Kind == MentionKind.Everyone)
         {
             _buffer.Append(
-                // language=HTML
+                // lang=html
                 """
                 <span class="chatlog__markdown-mention">@everyone</span>
                 """
@@ -206,7 +233,7 @@ internal partial class HtmlMarkdownVisitor : MarkdownVisitor
         else if (mention.Kind == MentionKind.Here)
         {
             _buffer.Append(
-                // language=HTML
+                // lang=html
                 """
                 <span class="chatlog__markdown-mention">@here</span>
                 """
@@ -225,7 +252,7 @@ internal partial class HtmlMarkdownVisitor : MarkdownVisitor
             var nick = member?.Nick ?? member?.User.Name ?? "Unknown";
 
             _buffer.Append(
-                // language=HTML
+                // lang=html
                 $"""
                 <span class="chatlog__markdown-mention" title="{HtmlEncode(fullName)}">@{HtmlEncode(nick)}</span>
                 """
@@ -238,7 +265,7 @@ internal partial class HtmlMarkdownVisitor : MarkdownVisitor
             var name = channel?.Name ?? "deleted-channel";
 
             _buffer.Append(
-                // language=HTML
+                // lang=html
                 $"""
                 <span class="chatlog__markdown-mention">{symbol}{HtmlEncode(name)}</span>
                 """
@@ -254,20 +281,18 @@ internal partial class HtmlMarkdownVisitor : MarkdownVisitor
                 ? $"""
                   color: rgb({color.Value.R}, {color.Value.G}, {color.Value.B}); background-color: rgba({color.Value.R}, {color.Value.G}, {color.Value.B}, 0.1);
                   """
-                : "";
+                : null;
 
             _buffer.Append(
-                // language=HTML
+                // lang=html
                 $"""
                 <span class="chatlog__markdown-mention" style="{style}">@{HtmlEncode(name)}</span>
                 """
             );
         }
-
-        return await base.VisitMentionAsync(mention, cancellationToken);
     }
 
-    protected override async ValueTask<MarkdownNode> VisitTimestampAsync(
+    protected override ValueTask VisitTimestampAsync(
         TimestampNode timestamp,
         CancellationToken cancellationToken = default)
     {
@@ -280,13 +305,13 @@ internal partial class HtmlMarkdownVisitor : MarkdownVisitor
         var formattedLong = timestamp.Instant?.ToLocalString("dddd, MMMM d, yyyy h:mm tt") ?? "";
 
         _buffer.Append(
-            // language=HTML
+            // lang=html
             $"""
             <span class="chatlog__markdown-timestamp" title="{HtmlEncode(formattedLong)}">{HtmlEncode(formatted)}</span>
             """
         );
 
-        return await base.VisitTimestampAsync(timestamp, cancellationToken);
+        return default;
     }
 }
 

DiscordChatExporter.Core/Exporting/PlainTextMarkdownVisitor.cs

@@ -18,15 +18,15 @@ internal partial class PlainTextMarkdownVisitor : MarkdownVisitor
         _buffer = buffer;
     }
 
-    protected override async ValueTask<MarkdownNode> VisitTextAsync(
+    protected override ValueTask VisitTextAsync(
         TextNode text,
         CancellationToken cancellationToken = default)
     {
         _buffer.Append(text.Text);
-        return await base.VisitTextAsync(text, cancellationToken);
+        return default;
     }
 
-    protected override async ValueTask<MarkdownNode> VisitEmojiAsync(
+    protected override ValueTask VisitEmojiAsync(
         EmojiNode emoji,
         CancellationToken cancellationToken = default)
     {
@@ -36,11 +36,10 @@ internal partial class PlainTextMarkdownVisitor : MarkdownVisitor
                 : emoji.Name
         );
 
-        return await base.VisitEmojiAsync(emoji, cancellationToken);
+        return default;
     }
 
-    protected override async ValueTask<MarkdownNode> VisitMentionAsync(
+    protected override async ValueTask VisitMentionAsync(MentionNode mention,
-        MentionNode mention,
         CancellationToken cancellationToken = default)
     {
         if (mention.Kind == MentionKind.Everyone)
@@ -82,11 +81,9 @@ internal partial class PlainTextMarkdownVisitor : MarkdownVisitor
 
             _buffer.Append($"@{name}");
         }
-
-        return await base.VisitMentionAsync(mention, cancellationToken);
     }
 
-    protected override async ValueTask<MarkdownNode> VisitTimestampAsync(
+    protected override ValueTask VisitTimestampAsync(
         TimestampNode timestamp,
         CancellationToken cancellationToken = default)
     {
@@ -98,7 +95,7 @@ internal partial class PlainTextMarkdownVisitor : MarkdownVisitor
                 : "Invalid date"
         );
 
-        return await base.VisitTimestampAsync(timestamp, cancellationToken);
+        return default;
     }
 }
 

DiscordChatExporter.Core/Exporting/PreambleTemplate.cshtml

@@ -759,27 +759,21 @@
         }
 
         .chatlog__markdown h1 {
-            margin-block: 0;
+            margin: 1rem 0 0.5rem;
-            margin-top: 1rem;
-            margin-bottom: 0.5rem;
             color: @Themed("#f2f3f5", "#060607");
             font-size: 1.5rem;
             line-height: 1;
         }
 
         .chatlog__markdown h2 {
-            margin-block: 0;
+            margin: 1rem 0 0.5rem;
-            margin-top: 1rem;
-            margin-bottom: 0.5rem;
             color: @Themed("#f2f3f5", "#060607");
             font-size: 1.25rem;
             line-height: 1;
         }
 
         .chatlog__markdown h3 {
-            margin-block: 0;
+            margin: 1rem 0 0.5rem;
-            margin-top: 1rem;
-            margin-bottom: 0.5rem;
             color: @Themed("#f2f3f5", "#060607");
             font-size: 1rem;
             line-height: 1;
@@ -789,6 +783,11 @@
             margin-top: 0.5rem;
         }
 
+        .chatlog__markdown ul, ol {
+            margin: 0 0 0 1rem;
+            padding: 0;
+        }
+
         .chatlog__markdown-preserve {
             white-space: pre-wrap;
         }

DiscordChatExporter.Core/Markdown/ListItemNode.cs

@@ -0,0 +1,5 @@
+using System.Collections.Generic;
+
+namespace DiscordChatExporter.Core.Markdown;
+
+internal record ListItemNode(IReadOnlyList<MarkdownNode> Children) : MarkdownNode, IContainerNode;

DiscordChatExporter.Core/Markdown/ListNode.cs

@@ -0,0 +1,5 @@
+using System.Collections.Generic;
+
+namespace DiscordChatExporter.Core.Markdown;
+
+internal record ListNode(IReadOnlyList<ListItemNode> Items) : MarkdownNode;

DiscordChatExporter.Core/Markdown/Parsing/MarkdownParser.cs

@@ -24,13 +24,13 @@ internal static partial class MarkdownParser
     /* Formatting */
 
     private static readonly IMatcher<MarkdownNode> BoldFormattingNodeMatcher = new RegexMatcher<MarkdownNode>(
-        // Capture any character until the earliest double asterisk not followed by an asterisk.
+        // There must be exactly two closing asterisks.
         new Regex(@"\*\*(.+?)\*\*(?!\*)", DefaultRegexOptions | RegexOptions.Singleline),
         (s, m) => new FormattingNode(FormattingKind.Bold, Parse(s.Relocate(m.Groups[1])))
     );
 
     private static readonly IMatcher<MarkdownNode> ItalicFormattingNodeMatcher = new RegexMatcher<MarkdownNode>(
-        // Capture any character until the earliest single asterisk not preceded or followed by an asterisk.
+        // There must be exactly one closing asterisk.
         // Opening asterisk must not be followed by whitespace.
         // Closing asterisk must not be preceded by whitespace.
         new Regex(@"\*(?!\s)(.+?)(?<!\s|\*)\*(?!\*)", DefaultRegexOptions | RegexOptions.Singleline),
@@ -38,27 +38,26 @@ internal static partial class MarkdownParser
     );
 
     private static readonly IMatcher<MarkdownNode> ItalicBoldFormattingNodeMatcher = new RegexMatcher<MarkdownNode>(
-        // Capture any character until the earliest triple asterisk not followed by an asterisk.
+        // There must be exactly three closing asterisks.
         new Regex(@"\*(\*\*.+?\*\*)\*(?!\*)", DefaultRegexOptions | RegexOptions.Singleline),
         (s, m) => new FormattingNode(FormattingKind.Italic, Parse(s.Relocate(m.Groups[1]), BoldFormattingNodeMatcher))
     );
 
     private static readonly IMatcher<MarkdownNode> ItalicAltFormattingNodeMatcher = new RegexMatcher<MarkdownNode>(
-        // Capture any character except underscore until an underscore.
         // Closing underscore must not be followed by a word character.
-        new Regex(@"_([^_]+)_(?!\w)", DefaultRegexOptions | RegexOptions.Singleline),
+        new Regex(@"_(.+?)_(?!\w)", DefaultRegexOptions | RegexOptions.Singleline),
         (s, m) => new FormattingNode(FormattingKind.Italic, Parse(s.Relocate(m.Groups[1])))
     );
 
     private static readonly IMatcher<MarkdownNode> UnderlineFormattingNodeMatcher = new RegexMatcher<MarkdownNode>(
-        // Capture any character until the earliest double underscore not followed by an underscore.
+        // There must be exactly two closing underscores.
         new Regex(@"__(.+?)__(?!_)", DefaultRegexOptions | RegexOptions.Singleline),
         (s, m) => new FormattingNode(FormattingKind.Underline, Parse(s.Relocate(m.Groups[1])))
     );
 
     private static readonly IMatcher<MarkdownNode> ItalicUnderlineFormattingNodeMatcher =
         new RegexMatcher<MarkdownNode>(
-            // Capture any character until the earliest triple underscore not followed by an underscore.
+            // There must be exactly three closing underscores.
             new Regex(@"_(__.+?__)_(?!_)", DefaultRegexOptions | RegexOptions.Singleline),
             (s, m) => new FormattingNode(
                 FormattingKind.Italic,
@@ -67,68 +66,61 @@ internal static partial class MarkdownParser
         );
 
     private static readonly IMatcher<MarkdownNode> StrikethroughFormattingNodeMatcher = new RegexMatcher<MarkdownNode>(
-        // Capture any character until the earliest double tilde.
         new Regex(@"~~(.+?)~~", DefaultRegexOptions | RegexOptions.Singleline),
         (s, m) => new FormattingNode(FormattingKind.Strikethrough, Parse(s.Relocate(m.Groups[1])))
     );
 
     private static readonly IMatcher<MarkdownNode> SpoilerFormattingNodeMatcher = new RegexMatcher<MarkdownNode>(
-        // Capture any character until the earliest double pipe.
         new Regex(@"\|\|(.+?)\|\|", DefaultRegexOptions | RegexOptions.Singleline),
         (s, m) => new FormattingNode(FormattingKind.Spoiler, Parse(s.Relocate(m.Groups[1])))
     );
 
     private static readonly IMatcher<MarkdownNode> SingleLineQuoteNodeMatcher = new RegexMatcher<MarkdownNode>(
-        // Capture any character until the end of the line.
+        // Include the linebreak in the content so that the lines are preserved in quotes.
-        // Opening 'greater than' character must be followed by whitespace.
-        // Consume the newline character so that it's not included in the content.
         new Regex(@"^>\s(.+\n?)", DefaultRegexOptions),
         (s, m) => new FormattingNode(FormattingKind.Quote, Parse(s.Relocate(m.Groups[1])))
     );
 
     private static readonly IMatcher<MarkdownNode> RepeatedSingleLineQuoteNodeMatcher = new RegexMatcher<MarkdownNode>(
-        // Repeatedly capture any character until the end of the line.
+        // Include the linebreaks in the content, so that the lines are preserved in quotes.
-        // Consume the newline character so that it's not included in the content.
         new Regex(@"(?:^>\s(.+\n?)){2,}", DefaultRegexOptions),
-        (_, m) => new FormattingNode(
+        (s, m) => new FormattingNode(
             FormattingKind.Quote,
-            Parse(
+            m.Groups[1].Captures.SelectMany(c => Parse(s.Relocate(c))).ToArray()
-                // Combine all captures into a single string
-                string.Concat(m.Groups[1].Captures.Select(c => c.Value))
-            )
         )
     );
 
     private static readonly IMatcher<MarkdownNode> MultiLineQuoteNodeMatcher = new RegexMatcher<MarkdownNode>(
-        // Capture any character until the end of the input.
-        // Opening 'greater than' characters must be followed by whitespace.
         new Regex(@"^>>>\s(.+)", DefaultRegexOptions | RegexOptions.Singleline),
         (s, m) => new FormattingNode(FormattingKind.Quote, Parse(s.Relocate(m.Groups[1])))
     );
 
-    /* Headers */
-
     private static readonly IMatcher<MarkdownNode> HeaderNodeMatcher = new RegexMatcher<MarkdownNode>(
-        // Capture any character until the end of the line.
+        // Consume the linebreak so that it's not attached to following nodes.
-        // Opening 'hash' character(s) must be followed by whitespace.
+        new Regex(@"^(\#{1,3})\s(.+)\n", DefaultRegexOptions),
-        // Consume the newline character so that it's not included in the content.
-        new Regex(@"^(\#{1,3})\s(.+\n?)", DefaultRegexOptions),
         (s, m) => new HeaderNode(m.Groups[1].Length, Parse(s.Relocate(m.Groups[2])))
     );
 
+    private static readonly IMatcher<MarkdownNode> ListNodeMatcher = new RegexMatcher<MarkdownNode>(
+        // Can be preceded by whitespace, which specifies the list's nesting level.
+        // Following lines that start with (level+1) whitespace are considered part of the list item.
+        // Consume the linebreak so that it's not attached to following nodes.
+        new Regex(@"^(\s*)(?:[\-\*]\s(.+(?:\n\s\1.*)*)?\n?)+", DefaultRegexOptions),
+        (s, m) => new ListNode(
+            m.Groups[2].Captures.Select(c => new ListItemNode(Parse(s.Relocate(c)))).ToArray()
+        )
+    );
+
     /* Code blocks */
 
     private static readonly IMatcher<MarkdownNode> InlineCodeBlockNodeMatcher = new RegexMatcher<MarkdownNode>(
-        // Capture any character except backtick until a backtick.
+        // One or two backticks are allowed, but they must match on both sides.
-        // Blank lines at the beginning and at the end of content are trimmed.
-        // There can be either one or two backticks, but equal number on both sides.
         new Regex(@"(`{1,2})([^`]+)\1", DefaultRegexOptions | RegexOptions.Singleline),
-        (_, m) => new InlineCodeBlockNode(m.Groups[2].Value.Trim('\r', '\n'))
+        (_, m) => new InlineCodeBlockNode(m.Groups[2].Value)
     );
 
     private static readonly IMatcher<MarkdownNode> MultiLineCodeBlockNodeMatcher = new RegexMatcher<MarkdownNode>(
-        // Capture language identifier and then any character until the earliest triple backtick.
+        // Language identifier is one word immediately after opening backticks, followed immediately by a linebreak.
-        // Language identifier is one word immediately after opening backticks, followed immediately by newline.
         // Blank lines at the beginning and at the end of content are trimmed.
         new Regex(@"```(?:(\w*)\n)?(.+?)```", DefaultRegexOptions | RegexOptions.Singleline),
         (_, m) => new MultiLineCodeBlockNode(m.Groups[1].Value, m.Groups[2].Value.Trim('\r', '\n'))
@@ -215,7 +207,7 @@ internal static partial class MarkdownParser
     );
 
     private static readonly IMatcher<MarkdownNode> CodedStandardEmojiNodeMatcher = new RegexMatcher<MarkdownNode>(
-        // Capture :thinking: for known emoji codes
+        // Capture :thinking:
         new Regex(@":([\w_]+):", DefaultRegexOptions),
         (_, m) => EmojiIndex.TryGetName(m.Groups[1].Value)?.Pipe(n => new EmojiNode(n))
     );
@@ -233,8 +225,8 @@ internal static partial class MarkdownParser
     /* Links */
 
     private static readonly IMatcher<MarkdownNode> AutoLinkNodeMatcher = new RegexMatcher<MarkdownNode>(
-        // Capture any non-whitespace character after http:// or https://
+        // Any non-whitespace character after http:// or https://
-        // until the last punctuation character or whitespace
+        // until the last punctuation character or whitespace.
         new Regex(@"(https?://\S*[^\.,:;""'\s])", DefaultRegexOptions),
         (_, m) => new LinkNode(m.Groups[1].Value)
     );
@@ -318,8 +310,7 @@ internal static partial class MarkdownParser
         }
     );
 
-    // Combine all matchers into one.
+    // Matchers that have similar patterns are ordered from most specific to least specific
-    // Matchers that have similar patterns are ordered from most specific to least specific.
     private static readonly IMatcher<MarkdownNode> NodeMatcher = new AggregateMatcher<MarkdownNode>(
         // Escaped text
         ShrugTextNodeMatcher,
@@ -339,9 +330,8 @@ internal static partial class MarkdownParser
         MultiLineQuoteNodeMatcher,
         RepeatedSingleLineQuoteNodeMatcher,
         SingleLineQuoteNodeMatcher,
-
-        // Headers
         HeaderNodeMatcher,
+        ListNodeMatcher,
 
         // Code blocks
         MultiLineCodeBlockNodeMatcher,

DiscordChatExporter.Core/Markdown/Parsing/MarkdownVisitor.cs

@@ -7,93 +7,127 @@ namespace DiscordChatExporter.Core.Markdown.Parsing;
 
 internal abstract class MarkdownVisitor
 {
-    protected virtual ValueTask<MarkdownNode> VisitTextAsync(
+    protected virtual ValueTask VisitTextAsync(
         TextNode text,
-        CancellationToken cancellationToken = default) =>
+        CancellationToken cancellationToken = default) => default;
-        new(text);
 
-    protected virtual async ValueTask<MarkdownNode> VisitFormattingAsync(
+    protected virtual async ValueTask VisitFormattingAsync(
         FormattingNode formatting,
-        CancellationToken cancellationToken = default)
+        CancellationToken cancellationToken = default) =>
-    {
         await VisitAsync(formatting.Children, cancellationToken);
-        return formatting;
-    }
 
-    protected virtual async ValueTask<MarkdownNode> VisitHeaderAsync(
+    protected virtual async ValueTask VisitHeaderAsync(
         HeaderNode header,
-        CancellationToken cancellationToken = default)
+        CancellationToken cancellationToken = default) =>
-    {
         await VisitAsync(header.Children, cancellationToken);
-        return header;
-    }
 
-    protected virtual ValueTask<MarkdownNode> VisitInlineCodeBlockAsync(
+    protected virtual async ValueTask VisitListAsync(
+        ListNode list,
+        CancellationToken cancellationToken = default) =>
+        await VisitAsync(list.Items, cancellationToken);
+
+    protected virtual async ValueTask VisitListItemAsync(
+        ListItemNode listItem,
+        CancellationToken cancellationToken = default) =>
+        await VisitAsync(listItem.Children, cancellationToken);
+
+    protected virtual ValueTask VisitInlineCodeBlockAsync(
         InlineCodeBlockNode inlineCodeBlock,
-        CancellationToken cancellationToken = default) =>
+        CancellationToken cancellationToken = default) => default;
-        new(inlineCodeBlock);
 
-    protected virtual ValueTask<MarkdownNode> VisitMultiLineCodeBlockAsync(
+    protected virtual ValueTask VisitMultiLineCodeBlockAsync(
         MultiLineCodeBlockNode multiLineCodeBlock,
-        CancellationToken cancellationToken = default) =>
+        CancellationToken cancellationToken = default) => default;
-        new(multiLineCodeBlock);
 
-    protected virtual async ValueTask<MarkdownNode> VisitLinkAsync(
+    protected virtual async ValueTask VisitLinkAsync(
         LinkNode link,
+        CancellationToken cancellationToken = default) =>
+        await VisitAsync(link.Children, cancellationToken);
+
+    protected virtual ValueTask VisitEmojiAsync(
+        EmojiNode emoji,
+        CancellationToken cancellationToken = default) => default;
+
+    protected virtual ValueTask VisitMentionAsync(
+        MentionNode mention,
+        CancellationToken cancellationToken = default) => default;
+
+    protected virtual ValueTask VisitTimestampAsync(
+        TimestampNode timestamp,
+        CancellationToken cancellationToken = default) => default;
+
+    public async ValueTask VisitAsync(
+        MarkdownNode node,
         CancellationToken cancellationToken = default)
     {
-        await VisitAsync(link.Children, cancellationToken);
+        if (node is TextNode text)
-        return link;
-    }
-
-    protected virtual ValueTask<MarkdownNode> VisitEmojiAsync(
-        EmojiNode emoji,
-        CancellationToken cancellationToken = default) =>
-        new(emoji);
-
-    protected virtual ValueTask<MarkdownNode> VisitMentionAsync(
-        MentionNode mention,
-        CancellationToken cancellationToken = default) =>
-        new(mention);
-
-    protected virtual ValueTask<MarkdownNode> VisitTimestampAsync(
-        TimestampNode timestamp,
-        CancellationToken cancellationToken = default) =>
-        new(timestamp);
-
-    public async ValueTask<MarkdownNode> VisitAsync(
-        MarkdownNode node,
-        CancellationToken cancellationToken = default) => node switch
         {
-            TextNode text =>
+            await VisitTextAsync(text, cancellationToken);
-                await VisitTextAsync(text, cancellationToken),
+            return;
+        }
 
-            FormattingNode formatting =>
+        if (node is FormattingNode formatting)
-                await VisitFormattingAsync(formatting, cancellationToken),
+        {
+            await VisitFormattingAsync(formatting, cancellationToken);
+            return;
+        }
 
-            HeaderNode header =>
+        if (node is HeaderNode header)
-                await VisitHeaderAsync(header, cancellationToken),
+        {
+            await VisitHeaderAsync(header, cancellationToken);
+            return;
+        }
 
-            InlineCodeBlockNode inlineCodeBlock =>
+        if (node is ListNode list)
-                await VisitInlineCodeBlockAsync(inlineCodeBlock, cancellationToken),
+        {
+            await VisitListAsync(list, cancellationToken);
+            return;
+        }
 
-            MultiLineCodeBlockNode multiLineCodeBlock =>
+        if (node is ListItemNode listItem)
-                await VisitMultiLineCodeBlockAsync(multiLineCodeBlock, cancellationToken),
+        {
+            await VisitListItemAsync(listItem, cancellationToken);
+            return;
+        }
 
-            LinkNode link =>
+        if (node is InlineCodeBlockNode inlineCodeBlock)
-                await VisitLinkAsync(link, cancellationToken),
+        {
+            await VisitInlineCodeBlockAsync(inlineCodeBlock, cancellationToken);
+            return;
+        }
 
-            EmojiNode emoji =>
+        if (node is MultiLineCodeBlockNode multiLineCodeBlock)
-                await VisitEmojiAsync(emoji, cancellationToken),
+        {
+            await VisitMultiLineCodeBlockAsync(multiLineCodeBlock, cancellationToken);
+            return;
+        }
 
-            MentionNode mention =>
+        if (node is LinkNode link)
-                await VisitMentionAsync(mention, cancellationToken),
+        {
+            await VisitLinkAsync(link, cancellationToken);
+            return;
+        }
 
-            TimestampNode timestamp =>
+        if (node is EmojiNode emoji)
-                await VisitTimestampAsync(timestamp, cancellationToken),
+        {
+            await VisitEmojiAsync(emoji, cancellationToken);
+            return;
+        }
 
-            _ => throw new ArgumentOutOfRangeException(nameof(node))
+        if (node is MentionNode mention)
-        };
+        {
+            await VisitMentionAsync(mention, cancellationToken);
+            return;
+        }
+
+        if (node is TimestampNode timestamp)
+        {
+            await VisitTimestampAsync(timestamp, cancellationToken);
+            return;
+        }
+
+        throw new ArgumentOutOfRangeException(nameof(node));
+    }
 
     public async ValueTask VisitAsync(
         IEnumerable<MarkdownNode> nodes,