Use TAG recommendations for returning promises

Manishearth · toji · commit f32c11ba10ab · 2019-06-14T13:23:35.000-07:00
diff --git a/index.bs b/index.bs
@@ -275,12 +275,15 @@ The <dfn attribute for="XR">ondevicechange</dfn> attribute is an [=Event handler
 
 <div class="algorithm" data-algorithm="supports-session">
 
-When the <dfn method for="XR">supportsSession(|mode|)</dfn> method is invoked, it MUST return [=a new Promise=] |promise| and run the following steps [=in parallel=]:
+When the <dfn method for="XR">supportsSession(|mode|)</dfn> method is invoked, it MUST run the following steps:
 
-  1. [=ensures an XR device is selected|Ensure an XR device is selected=].
-  1. If the [=XR/XR device=] is null, [=reject=] |promise| with a "{{NotSupportedError}}" {{DOMException}} and abort these steps.
-  1. If the [=XR/XR device=]'s [=list of supported modes=] does not [=list/contain=] |mode|, [=reject=] |promise| with a "{{NotSupportedError}}" {{DOMException}} and abort these steps.
-  1. [=/Resolve=] |promise|.
+  1. Let |promise| be [=a new Promise=]
+  1. Run the following steps [=in parallel=]:
+    1. [=ensures an XR device is selected|Ensure an XR device is selected=].
+    1. If the [=XR/XR device=] is null, [=reject=] |promise| with a "{{NotSupportedError}}" {{DOMException}} and abort these steps.
+    1. If the [=XR/XR device=]'s [=list of supported modes=] does not [=list/contain=] |mode|, [=reject=] |promise| with a "{{NotSupportedError}}" {{DOMException}} and abort these steps.
+    1. [=/Resolve=] |promise|.
+  1. Return |promise|.
 
 </div>
 
@@ -301,36 +304,39 @@ The {{XR}} object has a <dfn>pending immersive session</dfn> boolean, which MUST
 
 <div class="algorithm" data-algorithm="request-session">
 
-When the <dfn method for="XR">requestSession(|mode|)</dfn> method is invoked, the user agent MUST return [=a new Promise=] |promise| and run the following steps [=in parallel=]:
-
-  1. Let |immersive| be <code>true</code> if |mode| is {{XRSessionMode/"immersive-vr"}} or {{XRSessionMode/"immersive-ar"}}, and <code>false</code> otherwise.
-  1. If |immersive| is <code>true</code>: 
-    1. If the algorithm is not [=triggered by user activation=], [=reject=] |promise| with a "{{SecurityError}}" {{DOMException}} and abort these steps.
-    1. If [=pending immersive session=] is <code>true</code> or [=active immersive session=] is not <code>null</code>, [=reject=] |promise| with an "{{InvalidStateError}}" {{DOMException}} and abort these steps.
-    1. Set [=pending immersive session=] to be <code>true</code>.
-  1. [=ensures an XR device is selected|Ensure an XR device is selected=].
-  1. Follow the steps for the first matching conditions:
-      <dl class="switch">
-      <dt> If the [=XR/XR device=] is <code>null</code>
-      <dd> [=Reject=] |promise| with <code>null</code>.
-      <dt> If the [=XR/XR device=]'s [=list of supported modes=] does not [=list/contain=] |mode|
-      <dd> [=Reject=] |promise| with a "{{NotSupportedError}}" {{DOMException}}.
-      <dt> Otherwise
-      <dd> Continue to the next step.
-    </dl>
-  1. If |promise| was [=rejected=]:
-    1. If |immersive| is <code>true</code>, set [=pending immersive session=] to <code>false</code>.
-    1. Abort these steps.
-  1. Let |session| be a new {{XRSession}} object.
-  1. [=Initialize the session=] with |session| and |mode|.
-  1. Potentially set the [=active immersive session=] based on the following:
-    <dl class="switch">
-      <dt> If |immersive| is <code>true</code>
-      <dd> Set the [=active immersive session=] to |session|, and set [=pending immersive session=] to <code>false</code>.
-      <dt> Otherwise
-      <dd> Append |session| to the [=list of inline sessions=].
-    </dl>
-  1. [=/Resolve=] |promise| with |session|.
+When the <dfn method for="XR">requestSession(|mode|)</dfn> method is invoked, the user agent MUST run the following steps:
+
+  1. Let |promise| be [=a new Promise=].
+  1. Run the following steps [=in parallel=]:
+    1. Let |immersive| be <code>true</code> if |mode| is {{XRSessionMode/"immersive-vr"}} or {{XRSessionMode/"immersive-ar"}}, and <code>false</code> otherwise.
+    1. If |immersive| is <code>true</code>: 
+      1. If the algorithm is not [=triggered by user activation=], [=reject=] |promise| with a "{{SecurityError}}" {{DOMException}} and abort these steps.
+      1. If [=pending immersive session=] is <code>true</code> or [=active immersive session=] is not <code>null</code>, [=reject=] |promise| with an "{{InvalidStateError}}" {{DOMException}} and abort these steps.
+      1. Set [=pending immersive session=] to be <code>true</code>.
+    1. [=ensures an XR device is selected|Ensure an XR device is selected=].
+    1. Follow the steps for the first matching conditions:
+        <dl class="switch">
+          <dt> If the [=XR/XR device=] is <code>null</code>
+          <dd> [=Reject=] |promise| with <code>null</code>.
+          <dt> If the [=XR/XR device=]'s [=list of supported modes=] does not [=list/contain=] |mode|
+          <dd> [=Reject=] |promise| with a "{{NotSupportedError}}" {{DOMException}}.
+          <dt> Otherwise
+          <dd> Continue to the next step.
+        </dl>
+    1. If |promise| was [=rejected=]:
+      1. If |immersive| is <code>true</code>, set [=pending immersive session=] to <code>false</code>.
+      1. Abort these steps.
+    1. Let |session| be a new {{XRSession}} object.
+    1. [=Initialize the session=] with |session| and |mode|.
+    1. Potentially set the [=active immersive session=] based on the following:
+        <dl class="switch">
+          <dt> If |immersive| is <code>true</code>
+          <dd> Set the [=active immersive session=] to |session|, and set [=pending immersive session=] to <code>false</code>.
+          <dt> Otherwise
+          <dd> Append |session| to the [=list of inline sessions=].
+        </dl>
+    1. [=/Resolve=] |promise| with |session|.
+  1. Return |promise|.
 
 </div>
 
@@ -503,11 +509,14 @@ When requested, the {{XRSession}} MUST <dfn>apply pending render states</dfn> by
 
 <div class="algorithm" data-algorithm="request-reference-space">
 
-When the <dfn method for="XRSession">requestReferenceSpace(|type|)</dfn> method is invoked, the user agent MUST return [=a new Promise=] |promise| and run the following steps [=in parallel=]:
+When the <dfn method for="XRSession">requestReferenceSpace(|type|)</dfn> method is invoked, the user agent MUST run the following steps:
 
-  1. [=Create a reference space=], |referenceSpace|, with the {{XRReferenceSpaceType}} |type|.
-  1. If |referenceSpace| is <code>null</code>, [=reject=] |promise| with a {{NotSupportedError}} and abort these steps.
-  1. [=/Resolve=] |promise| with |referenceSpace|.
+  1. Let |promise| be [=a new Promise=].
+  1. Run the following steps [=in parallel=]:
+    1. [=Create a reference space=], |referenceSpace|, with the {{XRReferenceSpaceType}} |type|.
+    1. If |referenceSpace| is <code>null</code>, [=reject=] |promise| with a {{NotSupportedError}} and abort these steps.
+    1. [=/Resolve=] |promise| with |referenceSpace|.
+  1. Return |promise|.
 
 </div>
 
@@ -1754,20 +1763,23 @@ To set the [=XR compatible=] boolean after the context has been created, the {{m
 
 <div class="algorithm" data-algorithm="make-xr-compatible">
 
-When the <dfn method for="WebGLRenderingContextBase">makeXRCompatible()</dfn> method is invoked, the user agent MUST return [=a new Promise=] |promise| and run the following steps [=in parallel=]:
+When the <dfn method for="WebGLRenderingContextBase">makeXRCompatible()</dfn> method is invoked, the user agent MUST run the following steps:
 
-  1. Let |context| be the target {{WebGLRenderingContextBase}} object.
-  1. If |context|'s [=WebGL context lost flag=] is set, [=reject=] |promise| with an {{InvalidStateError}} and abort these abort these steps.
-  1. If |context|'s [=XR compatible=] boolean is <code>true</code>, [=/resolve=] |promise| and abort these steps.
-  1. If |context| was created on a [=compatible graphics adapter=] for the [=XR/XR device=]:
-      1. Set |context|'s [=XR compatible=] boolean to <code>true</code>.
-      1. [=/Resolve=] |promise| and abort these steps.
-  1. [=Queue a task=] to perform the following steps:
-      1. Force |context| to be lost and [=handle the context loss=] as described by the WebGL specification.
-      1. If the [=canceled flag=] of the "webglcontextlost" event fired in the previous step was not set, [=reject=] |promise| with an {{AbortError}} and abort these steps.
-      1. [=Restore the context=] on a [=compatible graphics adapter=] for the [=XR/XR device=].
-      1. Set |context|'s [=XR compatible=] boolean to <code>true</code>.
-      1. [=/Resolve=] |promise|.
+  1. Let |promise| be [=a new Promise=].
+    1. Run the following steps [=in parallel=]:
+    1. Let |context| be the target {{WebGLRenderingContextBase}} object.
+    1. If |context|'s [=WebGL context lost flag=] is set, [=reject=] |promise| with an {{InvalidStateError}} and abort these abort these steps.
+    1. If |context|'s [=XR compatible=] boolean is <code>true</code>, [=/resolve=] |promise| and abort these steps.
+    1. If |context| was created on a [=compatible graphics adapter=] for the [=XR/XR device=]:
+        1. Set |context|'s [=XR compatible=] boolean to <code>true</code>.
+        1. [=/Resolve=] |promise| and abort these steps.
+    1. [=Queue a task=] to perform the following steps:
+        1. Force |context| to be lost and [=handle the context loss=] as described by the WebGL specification.
+        1. If the [=canceled flag=] of the "webglcontextlost" event fired in the previous step was not set, [=reject=] |promise| with an {{AbortError}} and abort these steps.
+        1. [=Restore the context=] on a [=compatible graphics adapter=] for the [=XR/XR device=].
+        1. Set |context|'s [=XR compatible=] boolean to <code>true</code>.
+        1. [=/Resolve=] |promise|.
+  1. Return |promise|.
 
 </div>
 
