[selectors] Add scope-relative selectors to the grammar.

Author: tabatkins

selectors/Overview.html

@@ -329,32 +329,36 @@ <h2 class="no-num no-toc" id=contents>Table of Contents</h2>
      <li><a href="#enableddisabled"><span class=secno>11.1. </span> The
       <code>:enabled</code> and <code>:disabled</code> pseudo-classes</a>
 
-     <li><a href="#checked"><span class=secno>11.2. </span> The
+     <li><a href="#placeholder"><span class=secno>11.2. </span> The
+      placeholder-shown pseudo-class <code>:placeholder-shown</code></a>
+
+     <li><a href="#checked"><span class=secno>11.3. </span> The
       selected-option pseudo-class <code>:checked</code></a>
 
-     <li><a href="#indeterminate"><span class=secno>11.3. </span> The
+     <li><a href="#indeterminate"><span class=secno>11.4. </span> The
       indeterminate-value pseudo-class <code>:indeterminate</code></a>
 
-     <li><a href="#the-default-pseudo"><span class=secno>11.4. </span> The
+     <li><a href="#the-default-pseudo"><span class=secno>11.5. </span> The
       default option pseudo-class <code>:default</code></a>
 
-     <li><a href="#validity-pseudos"><span class=secno>11.5. </span> The
+     <li><a href="#validity-pseudos"><span class=secno>11.6. </span> The
       validity pseudo-classes: <code>:valid</code> and
       <code>:invalid</code></a>
 
-     <li><a href="#range-pseudos"><span class=secno>11.6. </span> The range
+     <li><a href="#range-pseudos"><span class=secno>11.7. </span> The range
       pseudo-classes <code>:in-range</code> and
       <code>:out-of-range</code></a>
 
-     <li><a href="#opt-pseudos"><span class=secno>11.7. </span> The
+     <li><a href="#opt-pseudos"><span class=secno>11.8. </span> The
       optionality pseudo-classes <code>:required</code> and
       <code>:optional</code></a>
 
-     <li><a href="#user-pseudos"><span class=secno>11.8. </span> The
+     <li><a href="#user-pseudos"><span class=secno>11.9. </span> The
       user-interaction pseudo-class <code>:user-error</code></a>
 
-     <li><a href="#rw-pseudos"><span class=secno>11.9. </span> The mutability
-      pseudo-classes <code>:read-only</code> and <code>:read-write</code></a>
+     <li><a href="#rw-pseudos"><span class=secno>11.10. </span> The
+      mutability pseudo-classes <code>:read-only</code> and
+      <code>:read-write</code></a>
     </ul>
 
    <li><a href="#structural-pseudos"><span class=secno>12. </span>
@@ -2821,7 +2825,17 @@ <h3 id=enableddisabled><span class=secno>11.1. </span> The <a
    <code>display</code> and <code>visibility</code> properties have no effect
    on the enabled/disabled state of an element.
 
-  <h3 id=checked><span class=secno>11.2. </span> The selected-option
+  <h3 id=placeholder><span class=secno>11.2. </span> The placeholder-shown
+   pseudo-class <a
+   href="#placeholder-shown-pseudo"><code>:placeholder-shown</code></a></h3>
+
+  <p>Input elements can sometimes show placeholder text as a hint to the user
+   on what to type in. See, for example, the <code>placeholder</code>
+   attribute in <a href="#HTML5" rel=biblioentry>[HTML5]<!--{{HTML5}}--></a>.
+   The <dfn id=placeholder-shown-pseudo>:placeholder-shown</dfn> pseudo-class
+   matches an input element that is showing such placeholder text.
+
+  <h3 id=checked><span class=secno>11.3. </span> The selected-option
    pseudo-class <a href="#checked-pseudo"><code>:checked</code></a></h3>
 
   <p>Radio and checkbox elements can be toggled by the user. Some menu items
@@ -2847,7 +2861,7 @@ <h3 id=checked><span class=secno>11.2. </span> The selected-option
    <pre>:not(:checked)</pre>
   </div>
 
-  <h3 id=indeterminate><span class=secno>11.3. </span> The
+  <h3 id=indeterminate><span class=secno>11.4. </span> The
    indeterminate-value pseudo-class <a
    href="#indetermine-pseudo"><code>:indeterminate</code></a></h3>
 
@@ -2866,7 +2880,7 @@ <h3 id=indeterminate><span class=secno>11.3. </span> The
    href="#indetermine-pseudo"><code>:indeterminate</code></a> even in a
    static display.
 
-  <h3 id=the-default-pseudo><span class=secno>11.4. </span> The default
+  <h3 id=the-default-pseudo><span class=secno>11.5. </span> The default
    option pseudo-class <a href="#default-pseudo"><code>:default</code></a></h3>
 
   <p>The <dfn id=default-pseudo>:default</dfn> pseudo-class applies to the
@@ -2880,7 +2894,7 @@ <h3 id=the-default-pseudo><span class=secno>11.4. </span> The default
    href="#default-pseudo"><code>:default</code></a> elements, like a
    selection of pizza toppings for example.
 
-  <h3 id=validity-pseudos><span class=secno>11.5. </span> The validity
+  <h3 id=validity-pseudos><span class=secno>11.6. </span> The validity
    pseudo-classes: <a href="#valid-pseudo"><code>:valid</code></a> and <a
    href="#invalid-pseudo"><code>:invalid</code></a></h3>
 
@@ -2904,7 +2918,7 @@ <h3 id=validity-pseudos><span class=secno>11.5. </span> The validity
    <code>&lt;p></code> element has no validity semantics at all, and so it
    never matches either of these pseudo-classes.
 
-  <h3 id=range-pseudos><span class=secno>11.6. </span> The range
+  <h3 id=range-pseudos><span class=secno>11.7. </span> The range
    pseudo-classes <a href="#in-range-psuedo"><code>:in-range</code></a> and
    <a href="#out-of-range-pseudo"><code>:out-of-range</code></a></h3>
 
@@ -2923,7 +2937,7 @@ <h3 id=range-pseudos><span class=secno>11.6. </span> The range
    menu element with a value of "E" that happens to be presented in a popup
    menu that only has choices "A", "B" and "C".
 
-  <h3 id=opt-pseudos><span class=secno>11.7. </span> The optionality
+  <h3 id=opt-pseudos><span class=secno>11.8. </span> The optionality
    pseudo-classes <a href="#required-pseudo"><code>:required</code></a> and
    <a href="#optional-pseudo"><code>:optional</code></a></h3>
 
@@ -2933,7 +2947,7 @@ <h3 id=opt-pseudos><span class=secno>11.7. </span> The optionality
    submitted. Elements that are not form elements are neither required nor
    optional.
 
-  <h3 id=user-pseudos><span class=secno>11.8. </span> The user-interaction
+  <h3 id=user-pseudos><span class=secno>11.9. </span> The user-interaction
    pseudo-class <a href="#user-error-pseudo"><code>:user-error</code></a></h3>
 
   <p> The <dfn id=user-error-pseudo>:user-error</dfn> pseudo-class represents
@@ -2983,7 +2997,7 @@ <h3 id=user-pseudos><span class=secno>11.8. </span> The user-interaction
     <code>:user-invalid</code> and <code>:user-omitted</code> could be used.
 -->
 
-  <h3 id=rw-pseudos><span class=secno>11.9. </span> The mutability
+  <h3 id=rw-pseudos><span class=secno>11.10. </span> The mutability
    pseudo-classes <a href="#read-only-pseudo"><code>:read-only</code></a> and
    <a href="#read-write-pseudo"><code>:read-write</code></a></h3>
 
@@ -3850,6 +3864,13 @@ <h3 id=grammar><span class=secno>16.1. </span> Grammar</h3>
       : complex_selector [ COMMA S* complex_selector ]*
       ;
 
+    scope_relative_selector_list
+      : scope_relative_selector [ COMMA s* scope_relative_selector ]*
+
+    scope_relative_selector
+      : combinator? complex_selector
+      ;
+
     complex_selector
       : compound_selector [ combinator compound_selector ]* S*
       ;
@@ -3921,6 +3942,26 @@ <h3 id=grammar><span class=secno>16.1. </span> Grammar</h3>
       : FUNCTION S* value ')'
       ;</pre>
 
+  <p> To aid with the authoring of property grammars, the following CSS
+   grammar productions are defined:
+
+  <dl>
+   <dt><dfn id=ltselector><var>&lt;selector></var></dfn>
+
+   <dd> A <code>complex_selector_list</code>.
+
+   <dt><dfn id=ltrelative-selector><var>&lt;relative-selector></var></dfn>
+
+   <dd> A <code>scope_relative_selector_list</code>.
+
+   <dt><dfn id=ltcompound-selector><var>&lt;compound-selector></var></dfn>
+
+   <dd> A <code>compound_selector_list</code>.
+
+   <dt><dfn id=ltid-selector><var>&lt;id-selector></var></dfn> An
+    <code>id</code>.
+  </dl>
+
   <h2 id=profiling><span class=secno>17. </span> Profiles</h2>
 
   <p>Each specification using Selectors must define the subset of Selectors

selectors/Overview.src.html

@@ -2816,6 +2816,13 @@ <h3 id="grammar">
       : complex_selector [ COMMA S* complex_selector ]*
       ;
 
+    scope_relative_selector_list
+      : scope_relative_selector [ COMMA s* scope_relative_selector ]*
+
+    scope_relative_selector
+      : combinator? complex_selector
+      ;
+
     complex_selector
       : compound_selector [ combinator compound_selector ]* S*
       ;
@@ -2887,6 +2894,27 @@ <h3 id="grammar">
       : FUNCTION S* value ')'
       ;</pre>
 
+  <p>
+    To aid with the authoring of property grammars,
+    the following CSS grammar productions are defined:
+
+  <dl>
+    <dt><dfn><var>&lt;selector></var></dfn>
+    <dd>
+      A <code>complex_selector_list</code>.
+
+    <dt><dfn><var>&lt;relative-selector></var></dfn>
+    <dd>
+      A <code>scope_relative_selector_list</code>.
+
+    <dt><dfn><var>&lt;compound-selector></var></dfn>
+    <dd>
+      A <code>compound_selector_list</code>.
+
+    <dt><dfn><var>&lt;id-selector></var></dfn>
+      An <code>id</code>.
+  </dl>
+
 
 
 <h2 id="profiling">