design: add explicit Proto declaration to every type

This is groundwork for eventually removing the _proto: *X` field from some
types (in order to save 8 bytes per, e.g. Node). For now, all `_proto: *X`
fields are untouched, BUT, all compile-time chain walking now happens against
this new declaration.

src/browser/Factory.zig

@@ -380,10 +380,7 @@ fn svgPrototypeTypes(comptime Child: type) []const type {
         var T = Child;
 
         while (T != EventTarget) {
-            if (!@hasField(T, "_proto")) {
-                @compileError(@typeName(T) ++ " does not lead to EventTarget through _proto");
-            }
-            T = reflect.Struct(@FieldType(T, "_proto"));
+            T = reflect.Proto(T) orelse @compileError(@typeName(T) ++ " does not lead to EventTarget through Proto");
             types = &[_]type{T} ++ types;
         }
 
@@ -425,7 +422,7 @@ pub fn destroy(self: *Factory, value: anytype) void {
         }
     }
 
-    if (comptime @hasField(S, "_proto")) {
+    if (comptime reflect.Proto(S) != null) {
         self.destroyChain(value, 0, std.mem.Alignment.@"1");
     } else {
         self.destroyStandalone(value);
@@ -451,7 +448,7 @@ fn destroyChain(
     const new_size = current_size + @sizeOf(S);
     const new_align = std.mem.Alignment.max(old_align, std.mem.Alignment.of(S));
 
-    if (@hasField(S, "_proto")) {
+    if (comptime reflect.Proto(S) != null) {
         self.destroyChain(value._proto, new_size, new_align);
     } else {
         // no proto so this is the head of the chain.

src/browser/js/Caller.zig

@@ -22,6 +22,7 @@ const string = @import("../../string.zig");
 
 const Page = @import("../Page.zig");
 const Frame = @import("../Frame.zig");
+const reflect = @import("../reflect.zig");
 
 const js = @import("js.zig");
 const Local = @import("Local.zig");
@@ -547,15 +548,14 @@ fn errorLocal(comptime T: type, local: *const Local, info: anytype) Local {
     };
 }
 
-// Upcast a Node-descendant instance to *Node by walking the _proto chain.
+// Upcast a Node-descendant instance to *Node by walking the Proto chain.
 // Not every node type defines an asNode() helper (e.g. Comment, Text), but
 // inheritsOrIs guarantees Node is in the chain
 fn protoNode(comptime T: type, instance: *T) *@import("../webapi/Node.zig") {
     if (T == @import("../webapi/Node.zig")) {
         return instance;
     }
-    const Proto = @typeInfo(std.meta.fieldInfo(T, ._proto).type).pointer.child;
-    return protoNode(Proto, instance._proto);
+    return protoNode(reflect.Proto(T).?, instance._proto);
 }
 
 fn handleError(comptime T: type, comptime F: type, local: *const Local, err: anyerror, info: anytype) void {

src/browser/js/Local.zig

@@ -25,6 +25,7 @@ const Page = @import("../Page.zig");
 
 const js = @import("js.zig");
 const bridge = @import("bridge.zig");
+const reflect = @import("../reflect.zig");
 const Caller = @import("Caller.zig");
 const Context = @import("Context.zig");
 const Isolate = @import("Isolate.zig");
@@ -1380,12 +1381,7 @@ fn findFinalizerType(comptime T: type) ?type {
     if (@hasDecl(S, "acquireRef")) {
         return S;
     }
-    if (@hasField(S, "_proto")) {
-        const ProtoPtr = std.meta.fieldInfo(S, ._proto).type;
-        const ProtoChild = @typeInfo(ProtoPtr).pointer.child;
-        return findFinalizerType(ProtoChild);
-    }
-    return null;
+    return findFinalizerType(reflect.Proto(S) orelse return null);
 }
 
 // Generate a function that follows the _proto pointer chain to get to the finalizer type
@@ -1398,10 +1394,8 @@ fn finalizerPtrGetter(comptime T: type, comptime FT: type) *const fn (*T) *FT {
             }
         }.get;
     }
-    if (@hasField(S, "_proto")) {
-        const ProtoPtr = std.meta.fieldInfo(S, ._proto).type;
-        const ProtoChild = @typeInfo(ProtoPtr).pointer.child;
-        const childGetter = comptime finalizerPtrGetter(ProtoChild, FT);
+    if (reflect.Proto(S)) |P| {
+        const childGetter = comptime finalizerPtrGetter(P, FT);
         return struct {
             fn get(v: *T) *FT {
                 return childGetter(v._proto);

src/browser/js/Snapshot.zig

@@ -21,6 +21,7 @@ const lp = @import("lightpanda");
 
 const js = @import("js.zig");
 const bridge = @import("bridge.zig");
+const reflect = @import("../reflect.zig");
 
 // Not ideal, but its children have special constructor rules (can be extended
 // can't be instantiated). And rather than coming up with a generic definition
@@ -693,11 +694,7 @@ fn protoIndexLookup(comptime JsApi: type) ?u16 {
     @setEvalBranchQuota(100_000);
     comptime {
         const T = JsApi.bridge.type;
-        if (!@hasField(T, "_proto")) {
-            return null;
-        }
-        const Ptr = std.meta.fieldInfo(T, ._proto).type;
-        const F = @typeInfo(Ptr).pointer.child;
+        const F = reflect.Proto(T) orelse return null;
         // Look up in the provided API list
         for (JsApis, 0..) |Api, i| {
             if (Api == F.JsApi) {

src/browser/js/bridge.zig

@@ -20,6 +20,7 @@ const std = @import("std");
 const lp = @import("lightpanda");
 
 const Frame = @import("../Frame.zig");
+const reflect = @import("../reflect.zig");
 
 const js = @import("js.zig");
 const Caller = @import("Caller.zig");
@@ -805,10 +806,7 @@ fn prototypeChainLength(comptime T: type) usize {
 
 // Given a Type, gets its prototype Type (if any)
 fn PrototypeType(comptime T: type) ?type {
-    if (!@hasField(T, "_proto")) {
-        return null;
-    }
-    return Struct(std.meta.fieldInfo(T, ._proto).type);
+    return reflect.Proto(T);
 }
 
 fn flattenTypes(comptime Types: []const type) [countFlattenedTypes(Types)]type {
@@ -1305,7 +1303,7 @@ pub const JsApis = blk: {
     break :blk base ++ [_]type{@import("../webapi/WebDriver.zig").JsApi};
 };
 
-// Whether Child is Ancestor or inherits from it, following the _proto chain.
+// Whether Child is Ancestor or inherits from it, following the Proto chain.
 pub fn inheritsOrIs(comptime Child: type, comptime Ancestor: type) bool {
     comptime {
         const target = Ancestor.bridge.type;
@@ -1314,10 +1312,7 @@ pub fn inheritsOrIs(comptime Child: type, comptime Ancestor: type) bool {
             if (T == target) {
                 return true;
             }
-            if (!@hasField(T, "_proto")) {
-                return false;
-            }
-            T = @typeInfo(std.meta.fieldInfo(T, ._proto).type).pointer.child;
+            T = reflect.Proto(T) orelse return false;
         }
     }
 }

src/browser/reflect.zig

@@ -16,6 +16,19 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+// The prototype ("parent") type of T, as declared by its `pub const Proto`.
+// This decl is the single source of truth for prototype-chain discovery;
+// a `_proto` field, where one exists, is only storage and must agree.
+pub fn Proto(comptime T: type) ?type {
+    if (!@hasDecl(T, "Proto")) {
+        return null;
+    }
+    if (@hasField(T, "_proto") and @FieldType(T, "_proto") != *T.Proto) {
+        @compileError(@typeName(T) ++ ": _proto field and Proto decl disagree");
+    }
+    return T.Proto;
+}
+
 // Gets the Parent of child.
 // HtmlElement.of(script) -> *HTMLElement
 pub fn Struct(comptime T: type) type {

src/browser/webapi/AbortSignal.zig

@@ -31,6 +31,8 @@ const Execution = js.Execution;
 
 const AbortSignal = @This();
 
+pub const Proto = EventTarget;
+
 const Dependend = union(enum) {
     signal: *AbortSignal,
     model_context_tool: *ModelContextTool,

src/browser/webapi/BroadcastChannel.zig

@@ -29,6 +29,8 @@ const Execution = js.Execution;
 
 const BroadcastChannel = @This();
 
+pub const Proto = EventTarget;
+
 _proto: *EventTarget,
 _exec: *Execution,
 _name: lp.String,

src/browser/webapi/CData.zig

@@ -32,10 +32,21 @@ const String = lp.String;
 
 const CData = @This();
 
+pub const Proto = Node;
+
 _type: Type,
 _proto: *Node,
 _data: String = .empty,
 
+pub const Type = union(enum) {
+    text: Text,
+    comment: Comment,
+    // This should be under Text, but that would require storing a _type union
+    // in text, which would add 8 bytes to every text node.
+    cdata_section: CDATASection,
+    processing_instruction: *ProcessingInstruction,
+};
+
 /// Count UTF-16 code units in a UTF-8 string.
 /// 4-byte UTF-8 sequences (codepoints >= U+10000) produce 2 UTF-16 code units (surrogate pair),
 /// everything else produces 1.
@@ -180,15 +191,6 @@ fn utf16RangeToUtf8(data: []const u8, utf16_start: usize, utf16_end: usize) !str
     return .{ .start = start, .end = i };
 }
 
-pub const Type = union(enum) {
-    text: Text,
-    comment: Comment,
-    // This should be under Text, but that would require storing a _type union
-    // in text, which would add 8 bytes to every text node.
-    cdata_section: CDATASection,
-    processing_instruction: *ProcessingInstruction,
-};
-
 pub fn asNode(self: *CData) *Node {
     return self._proto;
 }

src/browser/webapi/DOMMatrix.zig

@@ -24,6 +24,8 @@ const RO = @import("DOMMatrixReadOnly.zig");
 
 const DOMMatrix = @This();
 
+pub const Proto = RO;
+
 _proto: *RO,
 
 pub fn init(init_: ?js.Value, exec: *const js.Execution) !*DOMMatrix {

src/browser/webapi/DOMPoint.zig

@@ -22,6 +22,8 @@ const RO = @import("DOMPointReadOnly.zig");
 
 const DOMPoint = @This();
 
+pub const Proto = RO;
+
 _proto: *RO,
 
 pub fn init(x_: ?f64, y_: ?f64, z_: ?f64, w_: ?f64, exec: *const js.Execution) !*DOMPoint {

src/browser/webapi/DOMRect.zig

@@ -26,6 +26,8 @@ pub const Data = RO.Data;
 
 const DOMRect = @This();
 
+pub const Proto = RO;
+
 _proto: *RO,
 
 pub fn init(x_: ?f64, y_: ?f64, width_: ?f64, height_: ?f64, exec: *const js.Execution) !*DOMRect {

src/browser/webapi/DedicatedWorkerGlobalScope.zig

@@ -37,6 +37,8 @@ const Allocator = std.mem.Allocator;
 
 const DedicatedWorkerGlobalScope = @This();
 
+pub const Proto = WorkerGlobalScope;
+
 _proto: *WorkerGlobalScope,
 _worker: *Worker,
 _closed: bool = false,

src/browser/webapi/Document.zig

@@ -50,6 +50,8 @@ const IS_DEBUG = @import("builtin").mode == .Debug;
 
 const Document = @This();
 
+pub const Proto = Node;
+
 _type: Type,
 _proto: *Node,
 _frame: ?*Frame = null,

src/browser/webapi/DocumentFragment.zig

@@ -28,6 +28,8 @@ const Selector = @import("selector/Selector.zig");
 
 const DocumentFragment = @This();
 
+pub const Proto = Node;
+
 _type: Type,
 _proto: *Node,
 

src/browser/webapi/DocumentType.zig

@@ -25,6 +25,8 @@ const Node = @import("Node.zig");
 
 const DocumentType = @This();
 
+pub const Proto = Node;
+
 _proto: *Node,
 _name: []const u8,
 _public_id: []const u8,

src/browser/webapi/Element.zig

@@ -46,6 +46,8 @@ const String = lp.String;
 
 const Element = @This();
 
+pub const Proto = Node;
+
 pub const DatasetLookup = std.AutoHashMapUnmanaged(*Element, *DOMStringMap);
 pub const StyleLookup = std.AutoHashMapUnmanaged(*Element, *CSSStyleProperties);
 pub const ClassListLookup = std.AutoHashMapUnmanaged(*Element, *collections.DOMTokenList);

src/browser/webapi/File.zig

@@ -26,6 +26,8 @@ const Blob = @import("Blob.zig");
 
 const File = @This();
 
+pub const Proto = Blob;
+
 _proto: *Blob,
 _name: []const u8,
 _last_modified: i64,

src/browser/webapi/FileReader.zig

@@ -33,6 +33,8 @@ const Allocator = std.mem.Allocator;
 /// https://developer.mozilla.org/en-US/docs/Web/API/FileReader
 const FileReader = @This();
 
+pub const Proto = EventTarget;
+
 _rc: lp.RC = .{},
 _exec: *Execution,
 _proto: *EventTarget,

src/browser/webapi/HTMLDocument.zig

@@ -28,6 +28,8 @@ const collections = @import("collections.zig");
 
 const HTMLDocument = @This();
 
+pub const Proto = Document;
+
 _proto: *Document,
 _document_type: ?*DocumentType = null,
 

src/browser/webapi/MessagePort.zig

@@ -29,6 +29,8 @@ const Execution = js.Execution;
 
 const MessagePort = @This();
 
+pub const Proto = EventTarget;
+
 _proto: *EventTarget,
 
 // The context this port lives in. The two ends of an entangled pair can be in

src/browser/webapi/Node.zig

@@ -42,6 +42,8 @@ pub const AssignedSlotLookup = std.AutoHashMapUnmanaged(*Node, *Element.Html.Slo
 
 const Node = @This();
 
+pub const Proto = EventTarget;
+
 _type: Type,
 _proto: *EventTarget,
 _parent: ?*Node = null,

src/browser/webapi/Notification.zig

@@ -29,6 +29,8 @@ const Allocator = std.mem.Allocator;
 
 const Notification = @This();
 
+pub const Proto = EventTarget;
+
 _rc: lp.RC = .{},
 _arena: Allocator,
 _proto: *EventTarget,

src/browser/webapi/Performance.zig

@@ -444,6 +444,8 @@ pub const Entry = struct {
 };
 
 pub const Mark = struct {
+    pub const Proto = Entry;
+
     _proto: *Entry,
     _detail: ?js.Value.Global,
 
@@ -489,6 +491,8 @@ pub const Mark = struct {
 };
 
 pub const Measure = struct {
+    pub const Proto = Entry;
+
     _proto: *Entry,
     _detail: ?js.Value.Global,
 

src/browser/webapi/Range.zig

@@ -31,6 +31,8 @@ const String = lp.String;
 
 const Range = @This();
 
+pub const Proto = AbstractRange;
+
 _proto: *AbstractRange,
 
 pub fn init(frame: *Frame) !*Range {

src/browser/webapi/Screen.zig

@@ -29,6 +29,8 @@ pub fn registerTypes() []const type {
 
 const Screen = @This();
 
+pub const Proto = EventTarget;
+
 _proto: *EventTarget,
 _orientation: ?*Orientation = null,
 
@@ -72,6 +74,8 @@ pub const JsApi = struct {
 };
 
 pub const Orientation = struct {
+    pub const Proto = EventTarget;
+
     _proto: *EventTarget,
 
     pub fn init(frame: *Frame) !*Orientation {

src/browser/webapi/ShadowRoot.zig

@@ -26,6 +26,8 @@ const Element = @import("Element.zig");
 
 const ShadowRoot = @This();
 
+pub const Proto = DocumentFragment;
+
 pub const Mode = enum {
     open,
     closed,

src/browser/webapi/SharedWorker.zig

@@ -45,6 +45,8 @@ const log = lp.log;
 
 const SharedWorker = @This();
 
+pub const Proto = EventTarget;
+
 _proto: *EventTarget,
 _port: *MessagePort,
 _on_error: ?js.Function.Global = null,

src/browser/webapi/SharedWorkerGlobalScope.zig

@@ -36,6 +36,8 @@ const IS_DEBUG = @import("builtin").mode == .Debug;
 
 const SharedWorkerGlobalScope = @This();
 
+pub const Proto = WorkerGlobalScope;
+
 _proto: *WorkerGlobalScope,
 _arena: Allocator,
 

src/browser/webapi/StaticRange.zig

@@ -24,6 +24,8 @@ const AbstractRange = @import("AbstractRange.zig");
 
 const StaticRange = @This();
 
+pub const Proto = AbstractRange;
+
 // The boundary points and `collapsed` accessor live on the shared AbstractRange
 // prototype. Unlike Range, a StaticRange is *static*: the factory keeps it out
 // of the frame's live-range list, so DOM mutations never move its boundaries.

src/browser/webapi/VisualViewport.zig

@@ -22,6 +22,8 @@ const EventTarget = @import("EventTarget.zig");
 
 const VisualViewport = @This();
 
+pub const Proto = EventTarget;
+
 _proto: *EventTarget,
 
 pub fn asEventTarget(self: *VisualViewport) *EventTarget {

src/browser/webapi/Window.zig

@@ -64,6 +64,8 @@ pub fn registerTypes() []const type {
 
 const Window = @This();
 
+pub const Proto = EventTarget;
+
 _proto: *EventTarget,
 _frame: *Frame,
 _document: *Document,

src/browser/webapi/Worker.zig

@@ -36,6 +36,8 @@ const IS_DEBUG = @import("builtin").mode == .Debug;
 
 const Worker = @This();
 
+pub const Proto = EventTarget;
+
 pub const WorkerType = enum {
     classic,
     module,

src/browser/webapi/WorkerGlobalScope.zig

@@ -57,6 +57,8 @@ const Allocator = std.mem.Allocator;
 
 const WorkerGlobalScope = @This();
 
+pub const Proto = EventTarget;
+
 _type: Type,
 _frame: *Frame,
 _is_module: bool,

src/browser/webapi/XMLDocument.zig

@@ -23,6 +23,8 @@ const Node = @import("Node.zig");
 
 const XMLDocument = @This();
 
+pub const Proto = Document;
+
 _proto: *Document,
 
 pub fn asDocument(self: *XMLDocument) *Document {

src/browser/webapi/cdata/CDATASection.zig

@@ -22,6 +22,8 @@ const Text = @import("Text.zig");
 
 const CDATASection = @This();
 
+pub const Proto = Text;
+
 _proto: *Text,
 
 pub const JsApi = struct {

src/browser/webapi/cdata/Comment.zig

@@ -23,6 +23,8 @@ const CData = @import("../CData.zig");
 
 const Comment = @This();
 
+pub const Proto = CData;
+
 _proto: *CData,
 
 pub fn init(str: ?js.NullableString, frame: *Frame) !*Comment {

src/browser/webapi/cdata/ProcessingInstruction.zig

@@ -22,6 +22,8 @@ const CData = @import("../CData.zig");
 
 const ProcessingInstruction = @This();
 
+pub const Proto = CData;
+
 _proto: *CData,
 _target: []const u8,
 

src/browser/webapi/cdata/Text.zig

@@ -27,6 +27,8 @@ const slotting = @import("../element/slotting.zig");
 
 const Text = @This();
 
+pub const Proto = CData;
+
 _proto: *CData,
 
 pub fn init(str: ?js.NullableString, frame: *Frame) !*Text {

src/browser/webapi/collections/HTMLFormControlsCollection.zig

@@ -30,6 +30,8 @@ const IS_DEBUG = @import("builtin").mode == .Debug;
 
 const HTMLFormControlsCollection = @This();
 
+pub const Proto = HTMLCollection;
+
 _proto: *HTMLCollection,
 
 // The refcount lives on the proto, but anchoring the finalizer here lets

src/browser/webapi/collections/HTMLOptionsCollection.zig

@@ -25,6 +25,8 @@ const HTMLCollection = @import("HTMLCollection.zig");
 
 const HTMLOptionsCollection = @This();
 
+pub const Proto = HTMLCollection;
+
 _proto: *HTMLCollection,
 _select: *@import("../element/html/Select.zig"),
 

src/browser/webapi/collections/RadioNodeList.zig

@@ -29,6 +29,8 @@ const HTMLFormControlsCollection = @import("HTMLFormControlsCollection.zig");
 
 const RadioNodeList = @This();
 
+pub const Proto = NodeList;
+
 _proto: *NodeList,
 _name: []const u8,
 _form_collection: *HTMLFormControlsCollection,

src/browser/webapi/css/CSSStyleProperties.zig

@@ -25,6 +25,8 @@ const CSSStyleDeclaration = @import("CSSStyleDeclaration.zig");
 
 const CSSStyleProperties = @This();
 
+pub const Proto = CSSStyleDeclaration;
+
 _proto: *CSSStyleDeclaration,
 
 pub fn init(element: ?*Element, is_computed: bool, frame: *Frame) !*CSSStyleProperties {

src/browser/webapi/css/CSSStyleRule.zig

@@ -6,6 +6,8 @@ const CSSStyleProperties = @import("CSSStyleProperties.zig");
 
 const CSSStyleRule = @This();
 
+pub const Proto = CSSRule;
+
 _proto: *CSSRule,
 _selector_text: []const u8 = "",
 _style: ?*CSSStyleProperties = null,

src/browser/webapi/css/FontFaceSet.zig

@@ -32,6 +32,8 @@ const Allocator = std.mem.Allocator;
 
 const FontFaceSet = @This();
 
+pub const Proto = EventTarget;
+
 _rc: lp.RC = .{},
 _proto: *EventTarget,
 _arena: Allocator,

src/browser/webapi/css/MediaQueryList.zig

@@ -24,6 +24,8 @@ const MediaQuery = @import("../../css/MediaQuery.zig");
 
 const MediaQueryList = @This();
 
+pub const Proto = EventTarget;
+
 _proto: *EventTarget,
 _media: []const u8,
 

src/browser/webapi/element/Attribute.zig

@@ -41,6 +41,8 @@ pub fn registerTypes() []const type {
 
 pub const Attribute = @This();
 
+pub const Proto = Node;
+
 _proto: *Node,
 _name: String,
 _value: String,

src/browser/webapi/element/Html.zig

@@ -103,6 +103,8 @@ const IS_DEBUG = @import("builtin").mode == .Debug;
 
 const HtmlElement = @This();
 
+pub const Proto = Element;
+
 _type: Type,
 _proto: *Element,
 

src/browser/webapi/element/Svg.zig

@@ -41,6 +41,8 @@ pub const Stop = @import("svg/Stop.zig");
 const String = lp.String;
 
 const Svg = @This();
+
+pub const Proto = Element;
 _type: Type,
 _proto: *Element,
 _tag_name: String, // Svg elements are case-preserving

src/browser/webapi/element/html/Anchor.zig

@@ -26,6 +26,8 @@ const Element = @import("../../Element.zig");
 const HtmlElement = @import("../Html.zig");
 
 const Anchor = @This();
+
+pub const Proto = HtmlElement;
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Anchor) *Element {

src/browser/webapi/element/html/Area.zig

@@ -26,6 +26,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Area = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Area) *Element {

src/browser/webapi/element/html/Audio.zig

@@ -29,6 +29,8 @@ const String = lp.String;
 
 const Audio = @This();
 
+pub const Proto = Media;
+
 _proto: *Media,
 
 pub fn constructor(maybe_url: ?String, frame: *Frame) !*Media {

src/browser/webapi/element/html/BR.zig

@@ -5,6 +5,8 @@ const HtmlElement = @import("../Html.zig");
 
 const BR = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *BR) *Element {

src/browser/webapi/element/html/Base.zig

@@ -8,6 +8,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Base = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Base) *Element {

src/browser/webapi/element/html/Body.zig

@@ -29,6 +29,8 @@ const String = lp.String;
 
 const Body = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Body) *Element {

src/browser/webapi/element/html/Button.zig

@@ -32,6 +32,8 @@ const popover = @import("../popover.zig");
 
 const Button = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 _custom_validity: ?[]const u8 = null,
 _validity: ?*ValidityState = null,

src/browser/webapi/element/html/Canvas.zig

@@ -30,6 +30,8 @@ const OffscreenCanvas = @import("../../canvas/OffscreenCanvas.zig");
 const Execution = js.Execution;
 
 const Canvas = @This();
+
+pub const Proto = HtmlElement;
 _proto: *HtmlElement,
 _cached: ?DrawingContext = null,
 

src/browser/webapi/element/html/Custom.zig

@@ -33,6 +33,8 @@ const log = lp.log;
 const String = lp.String;
 
 const Custom = @This();
+
+pub const Proto = HtmlElement;
 _proto: *HtmlElement,
 _tag_name: String,
 _definition: ?*CustomElementDefinition,

src/browser/webapi/element/html/DList.zig

@@ -22,6 +22,8 @@ const Element = @import("../../Element.zig");
 const HtmlElement = @import("../Html.zig");
 
 const DList = @This();
+
+pub const Proto = HtmlElement;
 _proto: *HtmlElement,
 
 pub fn asElement(self: *DList) *Element {

src/browser/webapi/element/html/Data.zig

@@ -25,6 +25,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Data = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Data) *Element {

src/browser/webapi/element/html/DataList.zig

@@ -5,6 +5,8 @@ const HtmlElement = @import("../Html.zig");
 
 const DataList = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *DataList) *Element {

src/browser/webapi/element/html/Details.zig

@@ -7,6 +7,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Details = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Details) *Element {

src/browser/webapi/element/html/Dialog.zig

@@ -8,6 +8,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Dialog = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Dialog) *Element {

src/browser/webapi/element/html/Directory.zig

@@ -6,6 +6,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Directory = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Directory) *Element {

src/browser/webapi/element/html/Div.zig

@@ -22,6 +22,8 @@ const Element = @import("../../Element.zig");
 const HtmlElement = @import("../Html.zig");
 
 const Div = @This();
+
+pub const Proto = HtmlElement;
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Div) *Element {

src/browser/webapi/element/html/Embed.zig

@@ -23,6 +23,8 @@ const Element = @import("../../Element.zig");
 const HtmlElement = @import("../Html.zig");
 
 const Embed = @This();
+
+pub const Proto = HtmlElement;
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Embed) *Element {

src/browser/webapi/element/html/FieldSet.zig

@@ -6,6 +6,8 @@ const HtmlElement = @import("../Html.zig");
 
 const FieldSet = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *FieldSet) *Element {

src/browser/webapi/element/html/Font.zig

@@ -6,6 +6,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Font = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Font) *Element {

src/browser/webapi/element/html/Form.zig

@@ -31,6 +31,8 @@ pub const Select = @import("Select.zig");
 pub const TextArea = @import("TextArea.zig");
 
 const Form = @This();
+
+pub const Proto = HtmlElement;
 _proto: *HtmlElement,
 
 // Prevents submission of the form while we're in the process of submitting

src/browser/webapi/element/html/FrameSet.zig

@@ -11,6 +11,8 @@ const String = lp.String;
 
 const FrameSet = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *FrameSet) *Element {

src/browser/webapi/element/html/Generic.zig

@@ -27,6 +27,8 @@ const HtmlElement = @import("../Html.zig");
 const String = lp.String;
 
 const Generic = @This();
+
+pub const Proto = HtmlElement;
 _tag_name: String,
 _tag: Element.Tag,
 _proto: *HtmlElement,

src/browser/webapi/element/html/HR.zig

@@ -22,6 +22,8 @@ const Element = @import("../../Element.zig");
 const HtmlElement = @import("../Html.zig");
 
 const HR = @This();
+
+pub const Proto = HtmlElement;
 _proto: *HtmlElement,
 
 pub fn asElement(self: *HR) *Element {

src/browser/webapi/element/html/Head.zig

@@ -22,6 +22,8 @@ const Element = @import("../../Element.zig");
 const HtmlElement = @import("../Html.zig");
 
 const Head = @This();
+
+pub const Proto = HtmlElement;
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Head) *Element {

src/browser/webapi/element/html/Heading.zig

@@ -27,6 +27,8 @@ const HtmlElement = @import("../Html.zig");
 const String = lp.String;
 
 const Heading = @This();
+
+pub const Proto = HtmlElement;
 _proto: *HtmlElement,
 _tag_name: String,
 _tag: Element.Tag,

src/browser/webapi/element/html/Html.zig

@@ -22,6 +22,8 @@ const Element = @import("../../Element.zig");
 const HtmlElement = @import("../Html.zig");
 
 const Html = @This();
+
+pub const Proto = HtmlElement;
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Html) *Element {

src/browser/webapi/element/html/IFrame.zig

@@ -30,6 +30,8 @@ const DOMTokenList = @import("../../collections.zig").DOMTokenList;
 const HtmlElement = @import("../Html.zig");
 
 const IFrame = @This();
+
+pub const Proto = HtmlElement;
 _proto: *HtmlElement,
 _src: []const u8 = "",
 _executed: bool = false,

src/browser/webapi/element/html/Image.zig

@@ -6,6 +6,8 @@ const Element = @import("../../Element.zig");
 const HtmlElement = @import("../Html.zig");
 
 const Image = @This();
+
+pub const Proto = HtmlElement;
 _proto: *HtmlElement,
 
 pub fn constructor(w_: ?u32, h_: ?u32, frame: *Frame) !*Image {

src/browser/webapi/element/html/Input.zig

@@ -38,6 +38,8 @@ const String = lp.String;
 
 const Input = @This();
 
+pub const Proto = HtmlElement;
+
 pub const Type = enum {
     text,
     password,

src/browser/webapi/element/html/LI.zig

@@ -24,6 +24,8 @@ const Element = @import("../../Element.zig");
 const HtmlElement = @import("../Html.zig");
 
 const LI = @This();
+
+pub const Proto = HtmlElement;
 _proto: *HtmlElement,
 
 pub fn asElement(self: *LI) *Element {

src/browser/webapi/element/html/Label.zig

@@ -8,6 +8,8 @@ const TreeWalker = @import("../../TreeWalker.zig");
 
 const Label = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Label) *Element {

src/browser/webapi/element/html/Legend.zig

@@ -5,6 +5,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Legend = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Legend) *Element {

src/browser/webapi/element/html/Link.zig

@@ -27,6 +27,8 @@ const DOMTokenList = @import("../../collections.zig").DOMTokenList;
 const HtmlElement = @import("../Html.zig");
 
 const Link = @This();
+
+pub const Proto = HtmlElement;
 _proto: *HtmlElement,
 // Cached CSSStyleSheet for an external `rel=stylesheet` once
 // `Frame.loadExternalStylesheet` has registered it. Re-fetches (href

src/browser/webapi/element/html/Map.zig

@@ -5,6 +5,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Map = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Map) *Element {

src/browser/webapi/element/html/Marquee.zig

@@ -8,6 +8,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Marquee = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Marquee) *Element {

src/browser/webapi/element/html/Media.zig

@@ -30,6 +30,8 @@ const MediaError = @import("../../media/MediaError.zig");
 
 const Media = @This();
 
+pub const Proto = HtmlElement;
+
 pub const ReadyState = enum(u16) {
     HAVE_NOTHING = 0,
     HAVE_METADATA = 1,

src/browser/webapi/element/html/Meta.zig

@@ -23,6 +23,8 @@ const Element = @import("../../Element.zig");
 const HtmlElement = @import("../Html.zig");
 
 const Meta = @This();
+
+pub const Proto = HtmlElement;
 // Because we have a JsApi.Meta, "Meta" can be ambiguous in some scopes.
 // Create a different alias we can use when in such ambiguous cases.
 const MetaElement = Meta;

src/browser/webapi/element/html/Meter.zig

@@ -6,6 +6,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Meter = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Meter) *Element {

src/browser/webapi/element/html/Mod.zig

@@ -9,6 +9,8 @@ const String = lp.String;
 
 const Mod = @This();
 
+pub const Proto = HtmlElement;
+
 _tag_name: String,
 _tag: Element.Tag,
 _proto: *HtmlElement,

src/browser/webapi/element/html/OL.zig

@@ -24,6 +24,8 @@ const Element = @import("../../Element.zig");
 const HtmlElement = @import("../Html.zig");
 
 const OL = @This();
+
+pub const Proto = HtmlElement;
 _proto: *HtmlElement,
 
 pub fn asElement(self: *OL) *Element {

src/browser/webapi/element/html/Object.zig

@@ -5,6 +5,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Object = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Object) *Element {

src/browser/webapi/element/html/OptGroup.zig

@@ -6,6 +6,8 @@ const HtmlElement = @import("../Html.zig");
 
 const OptGroup = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *OptGroup) *Element {

src/browser/webapi/element/html/Option.zig

@@ -30,6 +30,8 @@ const String = lp.String;
 
 const Option = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 _value: ?[]const u8 = null,
 _selected: bool = false,

src/browser/webapi/element/html/Output.zig

@@ -27,6 +27,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Output = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Output) *Element {

src/browser/webapi/element/html/Paragraph.zig

@@ -22,6 +22,8 @@ const Element = @import("../../Element.zig");
 const HtmlElement = @import("../Html.zig");
 
 const Paragraph = @This();
+
+pub const Proto = HtmlElement;
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Paragraph) *Element {

src/browser/webapi/element/html/Param.zig

@@ -6,6 +6,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Param = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Param) *Element {

src/browser/webapi/element/html/Picture.zig

@@ -5,6 +5,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Picture = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Picture) *Element {

src/browser/webapi/element/html/Pre.zig

@@ -5,6 +5,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Pre = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Pre) *Element {

src/browser/webapi/element/html/Progress.zig

@@ -6,6 +6,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Progress = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 
 pub fn asElement(self: *Progress) *Element {

src/browser/webapi/element/html/Quote.zig

@@ -10,6 +10,8 @@ const String = lp.String;
 
 const Quote = @This();
 
+pub const Proto = HtmlElement;
+
 _tag_name: String,
 _tag: Element.Tag,
 _proto: *HtmlElement,

src/browser/webapi/element/html/Script.zig

@@ -26,6 +26,8 @@ const HtmlElement = @import("../Html.zig");
 
 const Script = @This();
 
+pub const Proto = HtmlElement;
+
 _proto: *HtmlElement,
 _src: []const u8 = "",
 _executed: bool = false,