Update framing algorithm to use embedded flag in _framing state_, defaulting to false, and set to true when recursing into node objects. Add tests to not add node at top level if embedded is false and it has already been serialized, and also use the check on @embed: @never to make that happen only when in an embedded node object.

Update test g010 to not use `@type` in framing.

For #27.

Author: gkellogg

common/algorithm-terms.html

@@ -13,11 +13,13 @@
     A flag specifying that for <a>properties</a> to be included in the output,
     they MUST be explicitly declared in the matching <a>frame</a>.</dd>
   <dt><dfn data-cite="JSON-LD11-FRAMING#dfn-framing-state">framing state</dfn></dt><dd>
-    A <a>map</a> containing values for the
-    <a>object embed flag</a>, the
-    <a>require all flag</a>, the
-    <a>explicit inclusion flag</a>, and the
-    <a>omit default flag</a>.</dd>
+    A <a>map</a> containing values for
+    the <a>object embed flag</a>,
+    the <a>require all flag</a>,
+    <span class="changed">the <a>embedded flag</a>,
+    used internally to help determine if object embedding is appropriate,</span>
+    the <a>explicit inclusion flag</a>,
+    and the <a>omit default flag</a>.</dd>
   <dt><dfn data-cite="JSON-LD11-FRAMING#dfn-input-frame">input frame</dfn></dt><dd>
     The initial <a>Frame</a> provided to the framing algorithm.</dd>
   <dt><dfn data-cite="JSON-LD11-API#dfn-json-ld-input">JSON-LD input</dfn></dt><dd>

index.html

@@ -1500,6 +1500,7 @@ <h3>Framing Algorithm</h3>
 <p>The recursive algorithm operates with a <a>framing state</a> (<var>state</var>),
   created initially using
   the <a>object embed flag</a> set to <code>@once</code>,
+  <span class="changed">the <dfn>embedded flag</dfn>, set to `false`,</span>
   the <a>explicit inclusion flag</a> set to <code>false</code>,
   the <a>require all flag</a> set to <code>true</code>,
   the <a>omit default flag</a> set to <code>false</code>,
@@ -1542,12 +1543,19 @@ <h3>Framing Algorithm</h3>
     <span class="changed">if the optional <a data-link-for="JsonLdOptions">ordered</a> flag is <code>true</code></span>:
     <ol>
       <li>Initialize <var>output</var> to a new <a>map</a> with <code>@id</code> and <var>id</var>.</li>
-      <li>Otherwise, if <var>embed</var> is <code>@never</code> or if a
+      <li class="changed">If the <a>embedded flag</a> in <var>state</var> is `false`
+        and there is an existing embedded node in <var>parent</var> associated with
+        <var>graph name</var> and <var>id</var> in <var>state</var>,
+        do not perform additional processing for this <var>node</var>.
+      </li>
+      <li class="changed">Otherwise, if the <a>embedded flag</a> in <var>state</var> is `true`
+        and either <var>embed</var> is <code>@never</code> or if a
         circular reference would be created by an embed,
         add <var>output</var> to <var>parent</var>
         and do not perform additional processing for this <var>node</var>.</li>
-      <li class="changed">Otherwise, if <var>embed</var> is <code>@once</code>
-        and parent has an existing embedded node in <var>parent</var> associated with
+      <li class="changed">Otherwise, if the <a>embedded flag</a> in <var>state</var> is `true`,
+        <var>embed</var> is <code>@once</code>,
+        and there is an existing embedded node in <var>parent</var> associated with
         <var>graph name</var> and <var>id</var> in <var>state</var>,
         add <var>output</var> to <var>parent</var>
         and do not perform additional processing for this <var>node</var>.</li>
@@ -1565,19 +1573,24 @@ <h3>Framing Algorithm</h3>
               <li>Push <var>graph name</var> from <var>state</var> onto <var>graph stack</var>
               in <var>state</var>.</li>
               <li>Set the value of <var>graph name</var> in <var>state</var> to <var>id</var>.</li>
-              <li>Invoke the recursive algorithm using <var>state</var>,
+              <li>Set the value of <a>embedded flag</a> in <var>state</var> to `false`.</li>
+              <li>Invoke the recursive algorithm
+                using a copy of <var>state</var>
+                with the value of <var>graph name</var> set to <var>id</var>
+                and the value of <a>embedded flag</a> set to `false`,
                 the keys from the <var>graph map</var> in <var>state</var> associated with id as <var>subjects</var>,
                 <var>subframe</var> as <var>frame</var>,
                 <var>output</var> as <var>parent</var>, and <code>@graph</code> as <var>active property</var>.
-              <li>Pop the value from <var>graph stack</var> in <var>state</var> and set <var>graph name</var> in <var>state</var>
-                back to that value.</li>
+              <li>Pop the value from <var>graph stack</var> in <var>state</var>.</li>
             </ol>
           </li>
         </ol>
       </li>
       <li class="changed">
         If <var>frame</var> has an `@included` <a>entry</a>,
-        invoke the recursive algorithm using <var>state</var>, <var>subjects</var>, <var>frame</var>,
+        invoke the recursive algorithm
+        using a copy of <var>state</var> with the value of <a>embedded flag</a> set to `true`,
+        <var>subjects</var>, <var>frame</var>,
         <var>output</var> as <var>parent</var>, and `@included` as <var>active property</var>.
       </li>
       <li>For each <var>property</var> and <var>objects</var> in <var>node</var>, ordered lexicographically by <var>property</var>
@@ -1595,7 +1608,8 @@ <h3>Framing Algorithm</h3>
                 in output:
                 <ol>
                   <li>If <var>listitem</var> is a <a>node reference</a>,
-                    invoke the recursive algorithm using <var>state</var>,
+                    invoke the recursive algorithm
+                    <span class="changed">using a copy of <var>state</var> with the value of <a>embedded flag</a> set to `true`</span>,
                     the value of <code>@id</code> from <var>listitem</var>
                     as the sole item in a new <var>subjects</var> <a>array</a>,
                     the first value from <code>@list</code> in <var>frame</var> as <var>frame</var>,
@@ -1608,7 +1622,8 @@ <h3>Framing Algorithm</h3>
                 </ol>
               </li>
               <li>If <var>item</var> is a <a>node reference</a>,
-                invoke the recursive algorithm using <var>state</var>,
+                invoke the recursive algorithm
+                <span class="changed">using a copy of <var>state</var> with the value of <a>embedded flag</a> set to `true`</span>,
                 the value of <code>@id</code> from <var>item</var>
                 as the sole item in a new <var>subjects</var> <a>array</a>,
                 the first value from <var>property</var> in <var>frame</var> as <var>frame</var>,
@@ -1646,7 +1661,8 @@ <h3>Framing Algorithm</h3>
                 <var>reverse property</var> containing a <a>node reference</a> with an <code>@id</code> of <var>id</var>:
                 <ol>
                   <li>Add <var>reverse property</var> to <var>reverse dict</var> with a new empty <a>array</a> as its value.</li>
-                  <li>Invoke the recursive algorithm using <var>state</var>,
+                  <li>Invoke the recursive algorithm
+                    <span class="changed">using a copy of <var>state</var> with the value of <a>embedded flag</a> set to `true`</span>,
                     the <var>reverse id</var>
                     as the sole item in a new <var>subjects</var> <a>array</a>,
                     <var>sub frame</var> as <var>frame</var>,

tests/frame/g010-frame.jsonld

@@ -5,8 +5,6 @@
   },
   "@graph": {
     "subject": {},
-    "proof": {
-      "@type": "ex:Proof"
-    }
+    "proof": {}
   }
 }