Editorial: Define SetTypedArrayFromArrayLike before SetTypedArrayFromTypedArray (#3632)

gibson042 · ljharb · commit 60c4df0b65e1 · 2025-06-30T14:26:05.000-07:00
The new [serendipitously alphabetical] ordering makes more obvious how
SetTypedArrayFromTypedArray is a specialized adaptation of
SetTypedArrayFromArrayLike when viewing the spec in top-to-bottom order.
diff --git a/spec.html b/spec.html
@@ -42181,6 +42181,37 @@ <h1>%TypedArray%.prototype.set ( _source_ [ , _offset_ ] )</h1>
         </emu-alg>
         <p>This method is not generic. The *this* value must be an object with a [[TypedArrayName]] internal slot.</p>
 
+        <emu-clause id="sec-settypedarrayfromarraylike" type="abstract operation" oldids="sec-%typedarray%.prototype.set-array-offset">
+          <h1>
+            SetTypedArrayFromArrayLike (
+              _target_: a TypedArray,
+              _targetOffset_: a non-negative integer or +&infin;,
+              _source_: an ECMAScript language value, but not a TypedArray,
+            ): either a normal completion containing ~unused~ or a throw completion
+          </h1>
+          <dl class="header">
+            <dt>description</dt>
+            <dd>It sets multiple values in _target_, starting at index _targetOffset_, reading the values from _source_.</dd>
+          </dl>
+          <emu-alg>
+            1. Let _targetRecord_ be MakeTypedArrayWithBufferWitnessRecord(_target_, ~seq-cst~).
+            1. If IsTypedArrayOutOfBounds(_targetRecord_) is *true*, throw a *TypeError* exception.
+            1. Let _targetLength_ be TypedArrayLength(_targetRecord_).
+            1. Let _src_ be ? ToObject(_source_).
+            1. Let _srcLength_ be ? LengthOfArrayLike(_src_).
+            1. If _targetOffset_ = +&infin;, throw a *RangeError* exception.
+            1. If _srcLength_ + _targetOffset_ > _targetLength_, throw a *RangeError* exception.
+            1. Let _k_ be 0.
+            1. Repeat, while _k_ &lt; _srcLength_,
+              1. Let _Pk_ be ! ToString(&#120125;(_k_)).
+              1. Let _value_ be ? Get(_src_, _Pk_).
+              1. Let _targetIndex_ be &#120125;(_targetOffset_ + _k_).
+              1. Perform ? TypedArraySetElement(_target_, _targetIndex_, _value_).
+              1. Set _k_ to _k_ + 1.
+            1. Return ~unused~.
+          </emu-alg>
+        </emu-clause>
+
         <emu-clause id="sec-settypedarrayfromtypedarray" type="abstract operation" oldids="sec-%typedarray%.prototype.set-typedarray-offset">
           <h1>
             SetTypedArrayFromTypedArray (
@@ -42236,37 +42267,6 @@ <h1>
             1. Return ~unused~.
           </emu-alg>
         </emu-clause>
-
-        <emu-clause id="sec-settypedarrayfromarraylike" type="abstract operation" oldids="sec-%typedarray%.prototype.set-array-offset">
-          <h1>
-            SetTypedArrayFromArrayLike (
-              _target_: a TypedArray,
-              _targetOffset_: a non-negative integer or +&infin;,
-              _source_: an ECMAScript language value, but not a TypedArray,
-            ): either a normal completion containing ~unused~ or a throw completion
-          </h1>
-          <dl class="header">
-            <dt>description</dt>
-            <dd>It sets multiple values in _target_, starting at index _targetOffset_, reading the values from _source_.</dd>
-          </dl>
-          <emu-alg>
-            1. Let _targetRecord_ be MakeTypedArrayWithBufferWitnessRecord(_target_, ~seq-cst~).
-            1. If IsTypedArrayOutOfBounds(_targetRecord_) is *true*, throw a *TypeError* exception.
-            1. Let _targetLength_ be TypedArrayLength(_targetRecord_).
-            1. Let _src_ be ? ToObject(_source_).
-            1. Let _srcLength_ be ? LengthOfArrayLike(_src_).
-            1. If _targetOffset_ = +&infin;, throw a *RangeError* exception.
-            1. If _srcLength_ + _targetOffset_ > _targetLength_, throw a *RangeError* exception.
-            1. Let _k_ be 0.
-            1. Repeat, while _k_ &lt; _srcLength_,
-              1. Let _Pk_ be ! ToString(&#120125;(_k_)).
-              1. Let _value_ be ? Get(_src_, _Pk_).
-              1. Let _targetIndex_ be &#120125;(_targetOffset_ + _k_).
-              1. Perform ? TypedArraySetElement(_target_, _targetIndex_, _value_).
-              1. Set _k_ to _k_ + 1.
-            1. Return ~unused~.
-          </emu-alg>
-        </emu-clause>
       </emu-clause>
 
       <emu-clause id="sec-%typedarray%.prototype.slice">
