Initial sync

Nbt/Util/QuotedWriter.cs

@@ -0,0 +1,128 @@
+using System.Text;
+
+namespace Nbt;
+
+public sealed class QuotedWriter(TextWriter baseWriter, char quoteChar, char escapeChar, bool leaveOpen = false) : TextWriter
+{
+    private readonly TextWriter baseWriter = baseWriter;
+    private readonly char quoteChar = quoteChar;
+    private readonly char escapeChar = escapeChar;
+    private readonly bool leaveOpen = leaveOpen;
+    private bool hasWrittenOneChar = false;
+
+    public QuotedWriter(StringBuilder sb, char quoteChar, char escapeChar) : this(new StringWriter(sb), quoteChar, escapeChar) { }
+
+    public override Encoding Encoding => baseWriter.Encoding;
+
+    public override void Write(char value)
+    {
+        if (!hasWrittenOneChar)
+        {
+            baseWriter.Write(quoteChar);
+            hasWrittenOneChar = true;
+        }
+
+        foreach (var c in Escape(value))
+        {
+            baseWriter.Write(c);
+        }
+    }
+
+    public override async Task WriteAsync(char value)
+    {
+        if (!hasWrittenOneChar)
+        {
+            await baseWriter.WriteAsync(quoteChar);
+            hasWrittenOneChar = true;
+        }
+
+        foreach (var c in Escape(value))
+        {
+            await baseWriter.WriteAsync(c);
+        }
+    }
+
+    private IEnumerable<char> Escape(char c)
+    {
+        var escape = false;
+
+        switch (c)
+        {
+            case '\t':
+                escape = true;
+                c = 't';
+                break;
+
+            case '\r':
+                escape = true;
+                c = 'r';
+                break;
+
+            case '\n':
+                escape = true;
+                c = 'n';
+                break;
+
+            default:
+                if (c == quoteChar || c == escapeChar)
+                {
+                    escape = true;
+                }
+                break;
+        }
+
+        if (escape)
+        {
+            yield return escapeChar;
+        }
+
+        yield return c;
+    }
+
+    protected override void Dispose(bool disposing)
+    {
+        try
+        {
+            if (disposing)
+            {
+                if (!hasWrittenOneChar)
+                {
+                    baseWriter.Write(quoteChar);
+                }
+
+                baseWriter.Write(quoteChar);
+
+                if (!leaveOpen)
+                {
+                    baseWriter.Dispose();
+                }
+            }
+        }
+        finally
+        {
+            base.Dispose(disposing);
+        }
+    }
+
+    public override async ValueTask DisposeAsync()
+    {
+        try
+        {
+            if (!hasWrittenOneChar)
+            {
+                await baseWriter.WriteAsync(quoteChar);
+            }
+
+            await baseWriter.WriteAsync(quoteChar);
+
+            if (!leaveOpen)
+            {
+                await baseWriter.DisposeAsync();
+            }
+        }
+        finally
+        {
+            await base.DisposeAsync();
+        }
+    }
+}