perf: parse uri when xaml compiled

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlCompiler.cs

@@ -30,7 +30,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
 
 
             // Before everything else
-            
+
             Transformers.Insert(0, new XNameTransformer());
             Transformers.Insert(1, new IgnoredDirectivesTransformer());
             Transformers.Insert(2, _designTransformer = new AvaloniaXamlIlDesignPropertiesTransformer());
@@ -49,7 +49,7 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
             InsertBefore<ContentConvertTransformer>(
                 new AvaloniaXamlIlControlThemeTransformer(),
                 new AvaloniaXamlIlSelectorTransformer(),
-                new AvaloniaXamlIlControlTemplateTargetTypeMetadataTransformer(),                 
+                new AvaloniaXamlIlControlTemplateTargetTypeMetadataTransformer(),
                 new AvaloniaXamlIlBindingPathParser(),
                 new AvaloniaXamlIlPropertyPathTransformer(),
                 new AvaloniaXamlIlSetterTargetTypeMetadataTransformer(),

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/AvaloniaXamlIlLanguageParseIntrinsics.cs

@@ -270,6 +270,27 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions
                 }
             }
 
+            if (type.Equals(types.Uri))
+            {
+                var uriText = text.Trim();
+
+                var kind = ((!uriText?.StartsWith("/") == true) ? UriKind.Absolute : UriKind.Relative);
+
+                if (string.IsNullOrWhiteSpace(uriText) || !Uri.TryCreate(uriText, kind, out var _))
+                {
+                        throw new XamlX.XamlLoadException($"Unable to parse text {uriText} as a {kind} uri.", node);
+                }
+                result = new XamlAstNewClrObjectNode(node
+                    , new(node, types.Uri, false)
+                    , types.UriConstructor
+                    , new List<IXamlAstValueNode>()
+                    {
+                        new XamlConstantNode(node, types.String, uriText),
+                        new XamlConstantNode(node, types.UriKind, (int)kind),
+                    });
+                return true;
+            }
+
             result = null;
             return false;
         }

src/Markup/Avalonia.Markup.Xaml.Loader/CompilerExtensions/Transformers/AvaloniaXamlIlWellKnownTypes.cs

@@ -101,6 +101,9 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
         public IXamlType IResourceDictionary { get; }
         public IXamlType ResourceDictionary { get; }
         public IXamlMethod ResourceDictionaryDeferredAdd { get; }
+        public IXamlType String { get; }
+        public IXamlType UriKind { get; }
+        public IXamlConstructor UriConstructor { get; }
 
         public AvaloniaXamlIlWellKnownTypes(TransformerConfiguration cfg)
         {
@@ -227,6 +230,9 @@ namespace Avalonia.Markup.Xaml.XamlIl.CompilerExtensions.Transformers
                 cfg.TypeSystem.GetType("System.Func`2").MakeGenericType(
                     cfg.TypeSystem.GetType("System.IServiceProvider"),
                     XamlIlTypes.Object));
+            String = cfg.TypeSystem.GetType("System.String");
+            UriKind = cfg.TypeSystem.GetType("System.UriKind");
+            UriConstructor = Uri.GetConstructor(new List<IXamlType>() { String, UriKind });
         }
     }