Specs: fix typos in style2.md, checkin forgotten builtins.md, add guard feature to runloop.md, rena…

sky/specs/builtins.md

Index: sky/specs/builtins.md
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+Built-In Elements
+=================
+
+```dart
+SKY MODULE
+
+<script>
+import 'dart:sky';
+
+class ImportElement extends Element {
+  ImportElement = Element;
+
+  @override
+  Type getLayoutManager() => null; // O(1)
+}
+
+class TemplateElement extends Element {
+  TemplateElement = Element;
+
+  // TODO(ianh): convert <template> to using a token stream instead of a Fragment
+
+  external Fragment get content; // O(1)
+
+  @override
+  Type getLayoutManager() => null; // O(1)
+}
+
+class ScriptElement extends Element {
+  ScriptElement = Element;
+
+  @override
+  Type getLayoutManager() => null; // O(1)
+}
+
+class StyleElement extends Element {
+  StyleElement = Element;
+
+  external List<Rule> getRules(); // O(N) in rules
+
+  @override
+  Type getLayoutManager() => null; // O(1)
+}
+
+class ContentElement extends Element {
+  ContentElement = Element;
+
+  external List<Node> getDistributedNodes(); // O(N) in distributed nodes
+
+  @override
+  Type getLayoutManager() => null; // O(1)
+}
+
+class ImgElement extends Element {
+  ImgElement = Element;
+
+  @override
+  Type getLayoutManager() => ImgElementLayoutManager; // O(1)
+}
+
+class DivElement extends Element {
+  DivElement = Element;
+}
+
+class SpanElement extends Element {
+  SpanElement = Element;
+}
+
+class IframeElement extends Element {
+  IframeElement = Element;
+
+  @override
+  Type getLayoutManager() => IframeElementLayoutManager; // O(1)
+}
+
+class TElement extends Element {
+  TElement = Element;
+}
+
+class AElement extends Element {
+  AElement = Element;
+}
+
+class TitleElement extends Element {
+  TitleElement = Element;
+
+  @override
+  Type getLayoutManager() => null; // O(1)
+}
+
+class _ErrorElement extends Element {
+  _ErrorElement._create();
+
+  @override
+  Type getLayoutManager() => _ErrorElementLayoutManager; // O(1)
+}
+
+void _init(script) {
+  module.registerElement('import', ImportElement);
+  module.registerElement('template', TemplateElement);
+  module.registerElement('script', ScriptElement);
+  module.registerElement('style', StyleElement);
+  module.registerElement('content', ContentElement);
+  module.registerElement('img', ImgElement);
+  module.registerElement('div', DivElement);
+  module.registerElement('span', SpanElement);
+  module.registerElement('iframe', IframeElement);
+  module.registerElement('t', TElement);
+  module.registerElement('a', AElement);
+  module.registerElement('title', TitleElement);
+}
+</script>
+```