Editorial: add parse and serialize a URL

This is the first step towards making parse a URL always return a URL record rather than a somewhat awkward tuple.

source

@@ -7070,19 +7070,19 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
   match that of the document or environment settings object for legacy reasons. When that is not the
   case the <span>URL parser</span> can be used directly.</p>
 
-  <p id="resolve-a-url">To <dfn>parse a URL</dfn> <var>url</var>, relative to either a
-  <var>document</var> or <var>environment settings object</var>, the user agent must use the
-  following steps. Parsing a URL either results in failure or a <span>resulting URL string</span>
-  and <span>resulting URL record</span>.</p>
+  <p id="resolve-a-url">To <dfn>parse a URL</dfn> <var>url</var>, relative to a
+  <code>Document</code> object or <span>environment settings object</span> <var>environment</var>,
+  run these steps. They return failure or a <span>resulting URL string</span> and <span>resulting
+  URL record</span>.</p>
 
   <ol>
-   <li><p>Let <var>encoding</var> be <var>document</var>'s <span data-x="document's character
-   encoding">character encoding</span>, if <var>document</var> was given, and <var>environment
-   settings object</var>'s <span>API URL character encoding</span> otherwise.</p></li>
+   <li><p>Let <var>encoding</var> be <var>environment</var>'s <span data-x="document's character
+   encoding">character encoding</span>, if <var>environment</var> is a <code>Document</code> object;
+   otherwise <var>environment</var>'s <span>API URL character encoding</span>.</p></li>
 
-   <li><p>Let <var>baseURL</var> be <var>document</var>'s <span data-x="document base URL">base
-   URL</span>, if <var>document</var> was given, and <var>environment settings object</var>'s
-   <span>API base URL</span> otherwise.</p></li>
+   <li><p>Let <var>baseURL</var> be <var>environment</var>'s <span data-x="document base URL">base
+   URL</span>, if <var>environment</var> is a <code>Document</code> object; otherwise
+   <var>environment</var>'s <span>API base URL</span> otherwise.</p></li>
 
    <li><p>Let <var>urlRecord</var> be the result of applying the <span>URL parser</span> to
    <var>url</var>, with <var>baseURL</var> and <var>encoding</var>.</p></li>
@@ -7096,6 +7096,17 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
    <var>urlRecord</var> as the <dfn>resulting URL record</dfn>.</p></li>
   </ol>
 
+  <p>To <dfn data-x="parsing and serializing a URL">parse and serialize a URL</dfn> <var>url</var>,
+  relative to a <code>Document</code> object or <span>environment settings object</span>
+  <var>environment</var>, run these steps. They return failure or a string.</p>
+
+  <ol>
+   <li><p><span>Parse a URL</span> <var>url</var>, relative to <var>environment</var>. If that
+   returns failure, then return failure.</p></li>
+
+   <li><p>Return the <span>resulting URL string</span>.</p></li>
+  </ol>
+
   </div>
 
 
@@ -7999,11 +8010,11 @@ a.setAttribute('href', 'https://example.com/'); // change the content attribute
       <ol>
        <li><p>If <var>contentAttributeValue</var> is null, then return the empty string.</p></li>
 
-       <li><p><span data-x="parse a url">Parse</span> <var>contentAttributeValue</var> relative to
-       the element's <span>node document</span>.</p></li>
+       <li><p>Let <var>urlString</var> be the result of <span>parsing and serializing a URL</span>
+       given <var>contentAttributeValue</var>, relative to <var>element</var>'s <span>node
+       document</span>.</p></li>
 
-       <li><p>If that does not return failure, then return the <span>resulting URL
-       string</span>.</p></li>
+       <li><p>If <var>urlString</var> is not failure, then return <var>urlString</var>.</p></li>
       </ol>
      </li>
 
@@ -25158,18 +25169,14 @@ document.body.appendChild(wbr);</code></pre>
 
    <li><p>If <var>targetNavigable</var> is null, then return.</p></li>
 
-   <li><p><span>Parse a URL</span> given <var>subject</var>'s <code
-   data-x="attr-hyperlink-href">href</code> attribute, relative to <var>subject</var>'s <span>node
-   document</span>.</p></li>
-
-   <li>
-    <p>If that is successful, let <var>url</var> be the <span>resulting URL string</span>.</p>
+   <li><p>Let <var>urlString</var> be the result of <span>parsing and serializing a URL</span> given
+   <var>subject</var>'s <code data-x="attr-hyperlink-href">href</code> attribute value, relative to
+   <var>subject</var>'s <span>node document</span>.</p></li>
 
-    <p>Otherwise, if <span data-x="parse a url">parsing</span> the <span>URL</span> failed, then
-    return.</p>
-   </li>
+   <li><p>If <var>urlString</var> is failure, then return.</p></li>
 
-   <li><p>If <var>hyperlinkSuffix</var> is non-null, then append it to <var>url</var>.</p></li>
+   <li><p>If <var>hyperlinkSuffix</var> is non-null, then append it to
+   <var>urlString</var>.</p></li>
 
    <li><p>Let <var>referrerPolicy</var> be the current state of <var>subject</var>'s <code
    data-x="">referrerpolicy</code> content attribute.</p></li>
@@ -25179,8 +25186,8 @@ document.body.appendChild(wbr);</code></pre>
    <var>referrerPolicy</var> to "<code data-x="">no-referrer</code>".</p></li>
 
    <li>
-    <p><span>Navigate</span><!--DONAV hyperlink--> <var>targetNavigable</var> to <var>url</var>
-    using <var>subject</var>'s <span>node document</span>, with <i
+    <p><span>Navigate</span><!--DONAV hyperlink--> <var>targetNavigable</var> to
+    <var>urlString</var> using <var>subject</var>'s <span>node document</span>, with <i
     data-x="navigation-referrer-policy">referrerPolicy</i> set to <var>referrerPolicy</var> and <i
     data-x="navigation-user-involvement">userInvolvement</i> set to <var>userInvolvement</var>.</p>
 
@@ -25234,15 +25241,14 @@ document.body.appendChild(wbr);</code></pre>
    sandboxing flag set</span> has the <span>sandboxed downloads browsing context flag</span> set,
    then return.</p></li>
 
-   <li><p><span>Parse a URL</span> given <var>subject</var>'s <code
-   data-x="attr-hyperlink-href">href</code> attribute, relative to <var>subject</var>'s <span>node
-   document</span>.</p></li>
+   <li><p>Let <var>urlString</var> be the result of <span>parsing and serializing a URL</span> given
+   <var>subject</var>'s <code data-x="attr-hyperlink-href">href</code> attribute value, relative to
+   <var>subject</var>'s <span>node document</span>.</p></li>
 
-   <li><p>If <span data-x="parse a url">parsing the URL</span> fails, then return.</p>
+   <li><p>If <var>urlString</var> is failure, then return.</p></li>
 
-   <li><p>Otherwise, let <var>url</var> be the <span>resulting URL string</span>.</p></li>
-
-   <li><p>If <var>hyperlinkSuffix</var> is non-null, then append it to <var>url</var>.</p></li>
+   <li><p>If <var>hyperlinkSuffix</var> is non-null, then append it to
+   <var>urlString</var>.</p></li>
 
    <li>
     <p>If <var>userInvolvement</var> is not "<code data-x="uni-browser-ui">browser UI</code>",
@@ -25261,9 +25267,10 @@ document.body.appendChild(wbr);</code></pre>
      <li><p>Let <var>continue</var> be the result of <span data-x="fire a download request navigate
      event">firing a download request <code data-x="event-navigate">navigate</code> event</span> at
      <var>navigation</var> with <i data-x="fire-navigate-download-destinationURL">destinationURL</i>
-     set to <var>url</var>, <i data-x="fire-navigate-download-userInvolvement">userInvolvement</i>
-     set to <var>userInvolvement</var>, and <i data-x="fire-navigate-download-filename">filename</i>
-     set to <var>filename</var>.</p></li>
+     set to <var>urlString</var>, <i
+     data-x="fire-navigate-download-userInvolvement">userInvolvement</i> set to
+     <var>userInvolvement</var>, and <i data-x="fire-navigate-download-filename">filename</i> set to
+     <var>filename</var>.</p></li>
 
      <li><p>If <var>continue</var> is false, then return.</p></li>
     </ol>
@@ -25277,10 +25284,10 @@ document.body.appendChild(wbr);</code></pre>
      safeguard the user from a potentially hostile download.</p></li>
 
      <li><p>Let <var>request</var> be a new <span data-x="concept-request">request</span> whose
-     <span data-x="concept-request-url">URL</span> is <var>url</var>,
-     <span data-x="concept-request-client">client</span> is <span>entry settings object</span>,
-     <span data-x="concept-request-initiator">initiator</span> is "<code data-x="">download</code>",
-     <span data-x="concept-request-destination">destination</span> is the empty string, and whose
+     <span data-x="concept-request-url">URL</span> is <var>urlString</var>, <span
+     data-x="concept-request-client">client</span> is <span>entry settings object</span>, <span
+     data-x="concept-request-initiator">initiator</span> is "<code data-x="">download</code>", <span
+     data-x="concept-request-destination">destination</span> is the empty string, and whose
      <span>synchronous flag</span> and <span>use-URL-credentials flag</span> are set.</p></li>
 
      <!--FETCH--><li><p>Handle the result of <span data-x="concept-fetch">fetching</span>
@@ -25485,9 +25492,9 @@ document.body.appendChild(wbr);</code></pre>
    data-x="">ping</code>".</p></li>
 
    <li>
-    <p>Let <var>target URL</var> be the <span>resulting URL string</span> obtained from <span
-    data-x="parse a url">parsing</span> the value of the element's <code
-    data-x="attr-hyperlink-href">href</code> attribute and then:</p>
+    <p>Let <var>target URL</var> be the result of <span>parsing and serializing a URL</span> given
+    the element's <code data-x="attr-hyperlink-href">href</code> attribute value, relative to the
+    element's <span>node document</span>, and then:</p>
 
     <dl class="switch">
      <dt>If the <span data-x="concept-document-url">URL</span> of the <code>Document</code> object
@@ -30464,11 +30471,13 @@ was an English &lt;a href="/wiki/Music_hall">music hall&lt;/a> singer, ...</code
     <p>If <var>selected source</var> is not null, then:</p>
 
     <ol>
-     <li><p><span data-x="parse a url">Parse</span> <var>selected source</var>, relative to the
-     element's <span>node document</span>. If that is not successful, then abort this inner set of
-     steps. Otherwise, let <var>urlString</var> be the <span>resulting URL string</span>.</p></li>
+     <li><p>Let <var>urlString</var> be the result of <span>parsing and serializing a URL</span>
+     given <var>selected source</var>, relative to the element's <span>node
+     document</span>.</p></li>
      <!-- This does not change currentSrc -->
 
+     <li><p>If <var>urlString</var> is failure, then abort this inner set of steps.</p></li>
+
      <li><p>Let <var>key</var> be a tuple consisting of <var>urlString</var>, the <code>img</code>
      element's <code data-x="attr-img-crossorigin">crossorigin</code> attribute's mode, and, if that
      mode is not <span data-x="attr-crossorigin-none">No CORS</span>, the <span>node
@@ -30576,10 +30585,11 @@ was an English &lt;a href="/wiki/Music_hall">music hall&lt;/a> singer, ...</code
     </ol>
    </li>
 
+   <li><p>Let <var>urlString</var> be the result of <span>parsing and serializing a URL</span> given
+   <var>selected source</var>, relative to the element's <span>node document</span>.</p></li>
+
    <li>
-    <p><span data-x="parse a url">Parse</span> <var>selected source</var>, relative to the element's
-    <span>node document</span>, and let <var>urlString</var> be the <span>resulting URL
-    string</span>. If that is not successful, then:</p>
+    <p>If <var>urlString</var> is failure, then:</p>
 
     <ol>
      <li><p><span>Abort the image request</span> for the <span>current request</span> and the
@@ -31530,9 +31540,11 @@ was an English &lt;a href="/wiki/Music_hall">music hall&lt;/a> singer, ...</code
    base URL resolution, so changing the base URL doesn't trigger an update if nothing else changed
    -->
 
-   <li><p>&#x231B; <span data-x="parse a url">Parse</span> <var>selected source</var>, relative to
-   the element's <span>node document</span>, and let <var>urlString</var> be the <span>resulting URL
-   string</span>. If that is not successful, then return.</p></li>
+   <li><p>&#x231B; Let <var>urlString</var> be the result of <span>parsing and serializing a
+   URL</span> given <var>selected source</var>, relative to the element's <span>node
+   document</span>.</p></li>
+
+   <li><p>&#x231B; If <var>urlString</var> is failure, then return.</p></li>
 
    <li><p>&#x231B; Let <var>corsAttributeState</var> be the state of the element's <code
    data-x="attr-img-crossorigin">crossorigin</code> content attribute.</p></li>
@@ -34904,11 +34916,23 @@ interface <dfn interface>HTMLTrackElement</dfn> : <span>HTMLElement</span> {
 
   <div w-nodev>
 
-  <p>If the element has a <code data-x="attr-track-src">src</code> attribute whose value is not the
-  empty string and whose value, when the attribute was set, could be successfully <span
-  data-x="parse a url">parsed</span> relative to the element's <span>node document</span>, then the
-  element's <dfn>track URL</dfn> is the <span>resulting URL string</span>. Otherwise, the element's
-  <span>track URL</span> is the empty string.</p>
+  <p>The element has an associated <dfn>track URL</dfn> (a string), initially the empty string.</p>
+
+  <p>When the element's <code data-x="attr-track-src">src</code> attribute is set, run these steps:
+
+  <ol>
+   <li><p>Let <var>trackURL</var> be failure.</p></li>
+
+   <li><p>Let <var>value</var> be the element's <code data-x="attr-track-src">src</code> attribute
+   value.</p></li>
+
+   <li><p>If <var>value</var> is not the empty string, then set <var>trackURL</var> to the result of
+   <span>parsing and serializing a URL</span> given <var>value</var>, relative to the element's
+   <span>node document</span>.</p></li>
+
+   <li><p>Set the element's <span>track URL</span> to <var>trackURL</var> if it is not failure;
+   otherwise to the empty string.</p></li>
+  </ol>
 
   </div>
 
@@ -74199,33 +74223,30 @@ Demos:
    <code>img</code>, <code>source</code>, <code>track</code>, or <code>video</code> element</dt>
 
    <dd>
-    <p>The value is the <span>resulting URL string</span> that results from <span data-x="parse a
-    url">parsing</span> the value of the element's <code data-x="">src</code> attribute relative to
-    the <span>node document</span> of the element at the time the attribute is set, or the empty
-    string if there is no such attribute or if <span data-x="parse a url">parsing</span> it results
-    in an error.</p>
+    <p>The value is the result of <span>parsing and serializing a URL</span> given the element's
+    <code data-x="">src</code> attribute value, relative to the element's <span>node
+    document</span>, at the time the attribute is set, or the empty string if there is no such
+    attribute or the result is failure.</p>
    </dd>
 
 
    <dt>If the element is an <code>a</code>, <code>area</code>, or <code>link</code> element</dt>
 
    <dd>
-    <p>The value is the <span>resulting URL string</span> that results from <span data-x="parse a
-    url">parsing</span> the value of the element's <code data-x="">href</code> attribute relative to
-    the <span>node document</span> of the element at the time the attribute is set, or the empty
-    string if there is no such attribute or if <span data-x="parse a url">parsing</span> it results
-    in an error.</p>
+    <p>The value is the result of <span>parsing and serializing a URL</span> given the element's
+    <code data-x="">href</code> attribute value, relative to the element's <span>node
+    document</span>, at the time the attribute is set, or the empty string if there is no such
+    attribute or the result is failure.</p>
    </dd>
 
 
    <dt>If the element is an <code>object</code> element</dt>
 
    <dd>
-    <p>The value is the <span>resulting URL string</span> that results from <span data-x="parse a
-    url">parsing</span> the value of the element's <code data-x="">data</code> attribute relative to
-    the <span>node document</span> of the element at the time the attribute is set, or the empty
-    string if there is no such attribute or if <span data-x="parse a url">parsing</span> it results
-    in an error.</p>
+    <p>The value is the result of <span>parsing and serializing a URL</span> given the element's
+    <code data-x="">data</code> attribute value, relative to the element's <span>node
+    document</span>, at the time the attribute is set, or the empty string if there is no such
+    attribute or the result is failure.</p>
    </dd>
 
 
@@ -128717,11 +128738,11 @@ html, body { display: block; }</code></pre>
   <hr>
 
   <p>When a <code>body</code> element has a <code data-x="attr-background">background</code>
-  attribute set to a non-empty value, the new value is expected to be <span data-x="parse a
-  url">parsed</span> relative to the element's <span>node document</span>, and if this is
-  successful, the user agent is expected to treat the attribute as a <span data-x="presentational
-  hints">presentational hint</span> setting the element's <span>'background-image'</span> property
-  to the <span>resulting URL string</span>.</p>
+  attribute set to a non-empty value, the new value is expected to be <span data-x="parsing and
+  serializing a URL">parsed and serialized</span> relative to the element's <span>node
+  document</span>, and if that does not return failure, the user agent is expected to treat the
+  attribute as a <span data-x="presentational hints">presentational hint</span> setting the
+  element's <span>'background-image'</span> property to the return value.</p>
 
   <p>When a <code>body</code> element has a <code data-x="attr-body-bgcolor">bgcolor</code>
   attribute set, the new value is expected to be parsed using the <span>rules for parsing a legacy
@@ -129563,10 +129584,11 @@ table {
   <p>When a <code>table</code>, <code>thead</code>, <code>tbody</code>, <code>tfoot</code>,
   <code>tr</code>, <code>td</code>, or <code>th</code> element has a <code
   data-x="attr-background">background</code> attribute set to a non-empty value, the new value is
-  expected to be <span data-x="parse a url">parsed</span> relative to the element's <span>node
-  document</span>, and if this is successful, the user agent is expected to treat the attribute as a
-  <span data-x="presentational hints">presentational hint</span> setting the element's
-  <span>'background-image'</span> property to the <span>resulting URL string</span>.</p>
+  expected to be <span data-x="parsing and serializing a URL">parsed and serialized</span> relative
+  to the element's <span>node document</span>, and if that does not return failure, the user agent
+  is expected to treat the attribute as a <span data-x="presentational hints">presentational
+  hint</span> setting the element's <span>'background-image'</span> property to the return
+  value.</p>
 
   <p>When a <code>table</code>, <code>thead</code>, <code>tbody</code>, <code>tfoot</code>,
   <code>tr</code>, <code>td</code>, or <code>th</code> element has a <code data-x="">bgcolor</code>