Define regexp().

Author: dbaron

css3-conditional/Overview.html

@@ -685,7 +685,8 @@ <h2 id=at-document><span class=secno>6. </span>Document queries: the
   <p class=issue>Given that this @-rule is intended primarily for user style
    sheets, what should this specification say about its use in author style
    sheets? Should it be forbidden? Should use instead be discouraged? Or
-   should this specification remain neutral on the topic?
+   should this specification remain neutral on the topic, since there are
+   valid uses in author style sheets?
 
   <p>The &lsquo;<code class=css>@document</code>&rsquo; rule's condition is
    written as a comma-separated list of <dfn id=url-matching-functions>URL
@@ -772,14 +773,42 @@ <h2 id=at-document><span class=secno>6. </span>Document queries: the
    <dt>regexp(&lt;string&gt;)
 
    <dd>
-    <p class=issue>Write me</p>
+    <p>The contents of the &lt;string&gt; argument <strong>must</strong>
+     match the JavaScript <code>Pattern</code> production. However, failing
+     to do so is not a CSS syntax error and does not trigger any error
+     handling for CSS syntax errors.</p>
+
+    <p>The &lsquo;<code class=css>regexp()</code>&rsquo; function evaluates
+     to true whenever the string argument compiled as a JavaScript regular
+     expression with the <code>global</code>, <code>ignoreCase</code> and
+     <code>multiline</code> flags <em>disabled</em> (see <a href="#ECMA-262"
+     rel=biblioentry>[ECMA-262]<!--{{!ECMA-262}}--></a> Edition 5, sections
+     15.10.7.2 through 15.10.7.4) compiles successfully and the resulting
+     regular expression matches the entirety of the URL of the page.</p>
+
+    <p class=note>Note that regular expression must match the entire URL, not
+     just a part of it.</p>
 
     <p class=note>This definition intentionally matches the behavior of the
      <a
      href="http://dev.w3.org/html5/spec/common-input-element-attributes.html#attr-input-pattern"><code
      class=html>pattern</code> attribute</a> on the <code
      class=html>input</code> element in <a href="#HTML5"
      rel=biblioentry>[HTML5]<!--{{HTML5}}--></a>.</p>
+
+    <div class=example>
+     <p>For example, this rule:</p>
+
+     <pre>@document regexp("http://www.w3.org/TR/\\d{4}/[^/]*-CSS2-\\d{8}/") {
+  body { font-size: 20px ! important }
+}</pre>
+
+     <p>changes the font size of the body element for pages such as
+      <code>http://www.w3.org/TR/2011/PR-CSS2-20110412/</code>.</p>
+
+     <p class=note>Note that the backslashes in the regular expression
+      require CSS escaping as &lsquo;<code class=css>\\</code>&rsquo;.</p>
+    </div>
   </dl>
 
   <p class=issue>What form of normalization is done on URLs and domains
@@ -996,6 +1025,15 @@ <h3 class=no-num id=normative-references>Normative references</h3>
     </dd>
    <!---->
 
+   <dt id=ECMA-262>[ECMA-262]
+
+   <dd><a
+    href="http://www.ecma-international.org/publications/standards/Ecma-262.htm"><cite>ECMAScript
+    Language Specification, Third Edition.</cite></a> December 1999. URL: <a
+    href="http://www.ecma-international.org/publications/standards/Ecma-262.htm">http://www.ecma-international.org/publications/standards/Ecma-262.htm</a>
+    </dd>
+   <!---->
+
    <dt id=MEDIAQ>[MEDIAQ]
 
    <dd>H&#229;kon Wium Lie; et al. <a

css3-conditional/Overview.src.html

@@ -495,7 +495,7 @@ <h2 id="at-document">Document queries: the '@document' rule</h2>
 style sheets, what should this specification say about its use in author
 style sheets?  Should it be forbidden?  Should use instead be
 discouraged?  Or should this specification remain neutral on the
-topic?</p>
+topic, since there are valid uses in author style sheets?</p>
 
 <p>The '@document' rule's condition is written as a
 comma-separated list of <dfn>URL matching functions</dfn>, and the
@@ -577,13 +577,38 @@ <h2 id="at-document">Document queries: the '@document' rule</h2>
   <dt>regexp(&lt;string&gt;)</dt>
 
   <dd>
-    <p class="issue">Write me</p>
+    <p>The contents of the &lt;string&gt; argument <strong>must</strong>
+    match the JavaScript <code>Pattern</code> production.  However,
+    failing to do so is not a CSS syntax error and does not trigger any
+    error handling for CSS syntax errors.</p>
+
+    <p>The ''regexp()'' function evaluates to true whenever the string
+    argument compiled as a JavaScript regular expression with the
+    <code>global</code>, <code>ignoreCase</code> and
+    <code>multiline</code> flags <em>disabled</em>
+    (see [[!ECMA-262]] Edition 5, sections 15.10.7.2 through 15.10.7.4)
+    compiles successfully and the resulting regular expression matches
+    the entirety of the URL of the page.</p>
+
+    <p class="note">Note that regular expression must match the entire
+    URL, not just a part of it.</p>
 
     <p class="note">This definition intentionally matches the behavior
     of the <a
     href="http://dev.w3.org/html5/spec/common-input-element-attributes.html#attr-input-pattern"><code class="html">pattern</code>
     attribute</a> on the <code class="html">input</code> element
     in [[HTML5]].</p>
+
+    <div class="example">
+      <p>For example, this rule:</p>
+<pre>@document regexp("http://www.w3.org/TR/\\d{4}/[^/]*-CSS2-\\d{8}/") {
+  body { font-size: 20px ! important }
+}</pre>
+      <p>changes the font size of the body element for pages such as
+      <code>http://www.w3.org/TR/2011/PR-CSS2-20110412/</code>.</p>
+      <p class="note">Note that the backslashes in the regular
+      expression require CSS escaping as ''\\''.</p>
+    </div>
   </dd>
 
 </dl>