Improve parsers

Emby.Naming/Video/CleanStringParser.cs

@@ -1,6 +1,8 @@
 #pragma warning disable CS1591
 #pragma warning disable SA1600
+#nullable enable
 
+using System;
 using System.Collections.Generic;
 using System.Text.RegularExpressions;
 
@@ -11,42 +13,33 @@ namespace Emby.Naming.Video
     /// </summary>
     public static class CleanStringParser
     {
-        public static CleanStringResult Clean(string name, IEnumerable<Regex> expressions)
+        public static bool TryClean(string name, IReadOnlyList<Regex> expressions, out ReadOnlySpan<char> newName)
         {
-            var hasChanged = false;
-
-            foreach (var exp in expressions)
+            var len = expressions.Count;
+            for (int i = 0; i < len; i++)
             {
-                var result = Clean(name, exp);
-
-                if (!string.IsNullOrEmpty(result.Name))
+                if (TryClean(name, expressions[i], out newName))
                 {
-                    name = result.Name;
-                    hasChanged = hasChanged || result.HasChanged;
+                    return true;
                 }
             }
 
-            return new CleanStringResult
-            {
-                Name = name,
-                HasChanged = hasChanged
-            };
+            newName = ReadOnlySpan<char>.Empty;
+            return false;
         }
 
-        private static CleanStringResult Clean(string name, Regex expression)
+        private static bool TryClean(string name, Regex expression, out ReadOnlySpan<char> newName)
         {
-            var result = new CleanStringResult();
-
             var match = expression.Match(name);
-
-            if (match.Success)
+            int index = match.Index;
+            if (match.Success && index != 0)
             {
-                result.HasChanged = true;
-                name = name.Substring(0, match.Index);
+                newName = name.AsSpan().Slice(0, match.Index);
+                return true;
             }
 
-            result.Name = name;
-            return result;
+            newName = string.Empty;
+            return false;
         }
     }
 }