From 74384a4b38dd82c6db489641494a148ebd9bf0b8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=2E=C2=A0S=2E=20Choi?= <jschoi@jschoi.org>
Date: Mon, 11 Jul 2022 14:52:06 -0400
Subject: [PATCH 1/3] =?UTF-8?q?Revert=20#20=20and=20do=20not=20await=20asy?=
 =?UTF-8?q?nc=20inputs=E2=80=99=20values=20without=20mapping=20=C6=92=20Cl?=
 =?UTF-8?q?oses=20#19.=20See=20<https://github.com/tc39/proposal-array-fro?=
 =?UTF-8?q?m-async/issues/19#issuecomment-1179810964>.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 README.md | 14 +++++++++-----
 spec.html |  6 +++---
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/README.md b/README.md
index 243118e..84bc4c8 100644
--- a/README.md
+++ b/README.md
@@ -219,11 +219,15 @@ const d = await Data.fromAsync(asyncGen(4));
 ### Optional parameters
 Array.fromAsync has two optional parameters: `mapfn` and `thisArg`.
 
-`mapfn` is a mapping callback, which is called on each value yielded from the
-input (and awaited if it came from a synchronous input), along with its index
-integer (starting from 0). Each result of the mapping callback is, in turn,
-awaited then added to the array. By default, the callback is essentially an
-identity function.
+`mapfn` is an optional mapping callback, which is called on each value yielded
+from the input (and awaited if it came from a synchronous input), along with
+its index integer (starting from 0). Each result of the mapping callback is, in
+turn, awaited then added to the array.
+
+(Without the optional mapping callback, each value yielded from asynchronous
+inputs is not awaited, and each value yielded from synchronous inputs is
+awaited only once, before the value is added to the result array. This matches
+the behavior of `for await`.)
 
 `thisArg` is a `this`-binding receiver value for the mapping callback. By
 default, this is undefined. These optional parameters match the behavior of
diff --git a/spec.html b/spec.html
index c0d4008..cfe1e95 100644
--- a/spec.html
+++ b/spec.html
@@ -74,10 +74,10 @@ <h1><ins>Array.fromAsync ( _asyncItems_ [ , _mapfn_ [ , _thisArg_ ] ] )</ins></h
               1. If _mapping_ is *true*, then
                 1. Let _mappedValue_ be Call(_mapfn_, _thisArg_, &laquo; _nextValue_, 𝔽(_k_) &raquo;).
                 1. IfAbruptCloseAsyncIterator(_iteratorRecord_, _mappedValue_).
+                1. Set _mappedValue_ to Await(_mappedValue_).
+                1. IfAbruptCloseAsyncIterator(_iteratorRecord_, _mappedValue_).
+                1. Set _mappedValue_ to _mappedValue_.[[Value]].
               1. Else, let _mappedValue_ be _nextValue_.
-              1. Set _mappedValue_ to Await(_mappedValue_).
-              1. IfAbruptCloseAsyncIterator(_iteratorRecord_, _mappedValue_).
-              1. Set _mappedValue_ to _mappedValue_.[[Value]].
               1. Let _defineStatus_ be CreateDataPropertyOrThrow(_A_, _Pk_, _mappedValue_).
               1. If _defineStatus_ is an abrupt completion, return ? AsyncIteratorClose(_iteratorRecord_, _defineStatus_).
               1. Set _k_ to _k_ + 1.

From b41554da653cc28205293ff681ff4b6c3974ad28 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=2E=C2=A0S=2E=C2=A0Choi?= <jschoi@jschoi.org>
Date: Mon, 11 Jul 2022 23:25:06 -0400
Subject: [PATCH 2/3] spec: Swap IfAbruptCloseAsyncIterator arguments

Co-authored-by: Kevin Gibbons <bakkot@gmail.com>
---
 spec.html | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/spec.html b/spec.html
index cfe1e95..99c511b 100644
--- a/spec.html
+++ b/spec.html
@@ -73,9 +73,9 @@ <h1><ins>Array.fromAsync ( _asyncItems_ [ , _mapfn_ [ , _thisArg_ ] ] )</ins></h
               1. Let _nextValue_ be ? IteratorValue(_next_).
               1. If _mapping_ is *true*, then
                 1. Let _mappedValue_ be Call(_mapfn_, _thisArg_, &laquo; _nextValue_, 𝔽(_k_) &raquo;).
-                1. IfAbruptCloseAsyncIterator(_iteratorRecord_, _mappedValue_).
+                1. IfAbruptCloseAsyncIterator(_mappedValue_, _iteratorRecord_).
                 1. Set _mappedValue_ to Await(_mappedValue_).
-                1. IfAbruptCloseAsyncIterator(_iteratorRecord_, _mappedValue_).
+                1. IfAbruptCloseAsyncIterator(_mappedValue_, _iteratorRecord_).
                 1. Set _mappedValue_ to _mappedValue_.[[Value]].
               1. Else, let _mappedValue_ be _nextValue_.
               1. Let _defineStatus_ be CreateDataPropertyOrThrow(_A_, _Pk_, _mappedValue_).

From 69ac2274fae4f2b13e06bcb2a8a35bc5a28efee2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=2E=C2=A0S=2E=20Choi?= <jschoi@jschoi.org>
Date: Tue, 12 Jul 2022 00:48:38 -0400
Subject: [PATCH 3/3] Remove redundant unwrapping of Completion Record
 IfAbruptCloseIterator already takes care of this.

---
 spec.html | 1 -
 1 file changed, 1 deletion(-)

diff --git a/spec.html b/spec.html
index 99c511b..5a774cd 100644
--- a/spec.html
+++ b/spec.html
@@ -76,7 +76,6 @@ <h1><ins>Array.fromAsync ( _asyncItems_ [ , _mapfn_ [ , _thisArg_ ] ] )</ins></h
                 1. IfAbruptCloseAsyncIterator(_mappedValue_, _iteratorRecord_).
                 1. Set _mappedValue_ to Await(_mappedValue_).
                 1. IfAbruptCloseAsyncIterator(_mappedValue_, _iteratorRecord_).
-                1. Set _mappedValue_ to _mappedValue_.[[Value]].
               1. Else, let _mappedValue_ be _nextValue_.
               1. Let _defineStatus_ be CreateDataPropertyOrThrow(_A_, _Pk_, _mappedValue_).
               1. If _defineStatus_ is an abrupt completion, return ? AsyncIteratorClose(_iteratorRecord_, _defineStatus_).