Make StringPart readonly struct

DiscordChatExporter.Core.Markdown/Internal/Extensions.cs

@@ -1,20 +1,10 @@
 using System;
 using System.Collections.Generic;
-using System.Text.RegularExpressions;
 
 namespace DiscordChatExporter.Core.Markdown.Internal
 {
     internal static class Extensions
     {
-        public static StringPart Shrink(this StringPart stringPart, int newStartIndex, int newLength) =>
-            new StringPart(stringPart.Target, newStartIndex, newLength);
-
-        public static StringPart Shrink(this StringPart stringPart, int newStartIndex) =>
-            stringPart.Shrink(newStartIndex, stringPart.EndIndex - newStartIndex);
-
-        public static StringPart Shrink(this StringPart stringPart, Capture capture) =>
-            stringPart.Shrink(capture.Index, capture.Length);
-
         public static IEnumerable<ParsedMatch<T>> MatchAll<T>(this IMatcher<T> matcher, StringPart stringPart,
             Func<StringPart, T> fallbackTransform)
         {
@@ -23,7 +13,7 @@ namespace DiscordChatExporter.Core.Markdown.Internal
             while (currentIndex < stringPart.EndIndex)
             {
                 // Find a match within this segment
-                var match = matcher.Match(stringPart.Shrink(currentIndex, stringPart.EndIndex - currentIndex));
+                var match = matcher.Match(stringPart.Slice(currentIndex, stringPart.EndIndex - currentIndex));
 
                 // If there's no match - break
                 if (match == null)
@@ -32,7 +22,7 @@ namespace DiscordChatExporter.Core.Markdown.Internal
                 // If this match doesn't start immediately at current index - transform and yield fallback first
                 if (match.StringPart.StartIndex > currentIndex)
                 {
-                    var fallbackPart = stringPart.Shrink(currentIndex, match.StringPart.StartIndex - currentIndex);
+                    var fallbackPart = stringPart.Slice(currentIndex, match.StringPart.StartIndex - currentIndex);
                     yield return new ParsedMatch<T>(fallbackPart, fallbackTransform(fallbackPart));
                 }
 
@@ -46,7 +36,7 @@ namespace DiscordChatExporter.Core.Markdown.Internal
             // If EOL wasn't reached - transform and yield remaining part as fallback
             if (currentIndex < stringPart.EndIndex)
             {
-                var fallbackPart = stringPart.Shrink(currentIndex);
+                var fallbackPart = stringPart.Slice(currentIndex);
                 yield return new ParsedMatch<T>(fallbackPart, fallbackTransform(fallbackPart));
             }
         }

DiscordChatExporter.Core.Markdown/Internal/RegexMatcher.cs

@@ -33,8 +33,8 @@ namespace DiscordChatExporter.Core.Markdown.Internal
             if (!_regex.IsMatch(stringPart.Target.Substring(0, stringPart.EndIndex), stringPart.StartIndex))
                 return null;
 
-            var stringPartShrunk = stringPart.Shrink(match.Index, match.Length);
-            return new ParsedMatch<T>(stringPartShrunk, _transform(stringPartShrunk, match));
+            var stringPartMatch = stringPart.Slice(match.Index, match.Length);
+            return new ParsedMatch<T>(stringPartMatch, _transform(stringPartMatch, match));
         }
     }
 }

DiscordChatExporter.Core.Markdown/Internal/StringMatcher.cs

@@ -26,8 +26,8 @@ namespace DiscordChatExporter.Core.Markdown.Internal
 
             if (index >= 0)
             {
-                var stringPartShrunk = stringPart.Shrink(index, _needle.Length);
-                return new ParsedMatch<T>(stringPartShrunk, _transform(stringPartShrunk));
+                var stringPartMatch = stringPart.Slice(index, _needle.Length);
+                return new ParsedMatch<T>(stringPartMatch, _transform(stringPartMatch));
             }
 
             return null;

DiscordChatExporter.Core.Markdown/Internal/StringPart.cs

@@ -1,6 +1,8 @@
-namespace DiscordChatExporter.Core.Markdown.Internal
+using System.Text.RegularExpressions;
+
+namespace DiscordChatExporter.Core.Markdown.Internal
 {
-    internal class StringPart
+    internal readonly struct StringPart
     {
         public string Target { get; }
 
@@ -23,6 +25,12 @@
         {
         }
 
+        public StringPart Slice(int newStartIndex, int newLength) => new StringPart(Target, newStartIndex, newLength);
+
+        public StringPart Slice(int newStartIndex) => Slice(newStartIndex, EndIndex - newStartIndex);
+
+        public StringPart Slice(Capture capture) => Slice(capture.Index, capture.Length);
+
         public override string ToString() => Target.Substring(StartIndex, Length);
     }
 }

DiscordChatExporter.Core.Markdown/MarkdownParser.cs

@@ -16,57 +16,57 @@ namespace DiscordChatExporter.Core.Markdown
         // Capture any character until the earliest double asterisk not followed by an asterisk
         private static readonly IMatcher<Node> BoldFormattedNodeMatcher = new RegexMatcher<Node>(
             new Regex("\\*\\*(.+?)\\*\\*(?!\\*)", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Bold, Parse(p.Shrink(m.Groups[1]))));
+            (p, m) => new FormattedNode(TextFormatting.Bold, Parse(p.Slice(m.Groups[1]))));
 
         // Capture any character until the earliest single asterisk not preceded or followed by an asterisk
         // Opening asterisk must not be followed by whitespace
         // Closing asterisk must not be preceded by whitespace
         private static readonly IMatcher<Node> ItalicFormattedNodeMatcher = new RegexMatcher<Node>(
             new Regex("\\*(?!\\s)(.+?)(?<!\\s|\\*)\\*(?!\\*)", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Italic, Parse(p.Shrink(m.Groups[1]))));
+            (p, m) => new FormattedNode(TextFormatting.Italic, Parse(p.Slice(m.Groups[1]))));
 
         // Capture any character until the earliest triple asterisk not followed by an asterisk
         private static readonly IMatcher<Node> ItalicBoldFormattedNodeMatcher = new RegexMatcher<Node>(
             new Regex("\\*(\\*\\*.+?\\*\\*)\\*(?!\\*)", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Italic, Parse(p.Shrink(m.Groups[1]), BoldFormattedNodeMatcher)));
+            (p, m) => new FormattedNode(TextFormatting.Italic, Parse(p.Slice(m.Groups[1]), BoldFormattedNodeMatcher)));
 
         // Capture any character except underscore until an underscore
         // Closing underscore must not be followed by a word character
         private static readonly IMatcher<Node> ItalicAltFormattedNodeMatcher = new RegexMatcher<Node>(
             new Regex("_([^_]+)_(?!\\w)", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Italic, Parse(p.Shrink(m.Groups[1]))));
+            (p, m) => new FormattedNode(TextFormatting.Italic, Parse(p.Slice(m.Groups[1]))));
 
         // Capture any character until the earliest double underscore not followed by an underscore
         private static readonly IMatcher<Node> UnderlineFormattedNodeMatcher = new RegexMatcher<Node>(
             new Regex("__(.+?)__(?!_)", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Underline, Parse(p.Shrink(m.Groups[1]))));
+            (p, m) => new FormattedNode(TextFormatting.Underline, Parse(p.Slice(m.Groups[1]))));
 
         // Capture any character until the earliest triple underscore not followed by an underscore
         private static readonly IMatcher<Node> ItalicUnderlineFormattedNodeMatcher = new RegexMatcher<Node>(
             new Regex("_(__.+?__)_(?!_)", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Italic, Parse(p.Shrink(m.Groups[1]), UnderlineFormattedNodeMatcher)));
+            (p, m) => new FormattedNode(TextFormatting.Italic, Parse(p.Slice(m.Groups[1]), UnderlineFormattedNodeMatcher)));
 
         // Capture any character until the earliest double tilde
         private static readonly IMatcher<Node> StrikethroughFormattedNodeMatcher = new RegexMatcher<Node>(
             new Regex("~~(.+?)~~", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Strikethrough, Parse(p.Shrink(m.Groups[1]))));
+            (p, m) => new FormattedNode(TextFormatting.Strikethrough, Parse(p.Slice(m.Groups[1]))));
 
         // Capture any character until the earliest double pipe
         private static readonly IMatcher<Node> SpoilerFormattedNodeMatcher = new RegexMatcher<Node>(
             new Regex("\\|\\|(.+?)\\|\\|", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Spoiler, Parse(p.Shrink(m.Groups[1]))));
+            (p, m) => new FormattedNode(TextFormatting.Spoiler, Parse(p.Slice(m.Groups[1]))));
 
         // Capture any character until the end of the line
         // Opening 'greater than' character must be followed by whitespace
         private static readonly IMatcher<Node> SingleLineQuoteNodeMatcher = new RegexMatcher<Node>(
             new Regex("^>\\s(.+)\r?\n?", DefaultRegexOptions),
-            (p, m) => new FormattedNode(TextFormatting.Quote, Parse(p.Shrink(m.Groups[1]))));
+            (p, m) => new FormattedNode(TextFormatting.Quote, Parse(p.Slice(m.Groups[1]))));
 
         // Capture any character until the end of the input
         // Opening 'greater than' characters must be followed by whitespace
         private static readonly IMatcher<Node> MultiLineQuoteNodeMatcher = new RegexMatcher<Node>(
             new Regex("^>>>\\s(.+)", DefaultRegexOptions | RegexOptions.Singleline),
-            (p, m) => new FormattedNode(TextFormatting.Quote, Parse(p.Shrink(m.Groups[1]))));
+            (p, m) => new FormattedNode(TextFormatting.Quote, Parse(p.Slice(m.Groups[1]))));
 
         /* Code blocks */