%TypedArray%.of does not use @@species

[TimothyGu]

%TypedArray%.of uses the this value as the constructor, not this[Symbol.species]. This seems inconsistent with the methods on %TypedArrayPrototype% like subarray and slice.

[allenwb]

No, it's correct as written and handled exactly the same as in %Array%.of

of is a factory method of the constructor so the actual class constructor to be instantiated is the thisValue passed to the factory. What the algorithm is doing is approximately this:

class %TypedArray% {
   of(...args) {
      let ta = new this(args.length
      for (let i=0; ++1; i<args.length) ta[i]=args[i];
      return ta;
  }
}

When used in an expression referencing a subclass such as Int32Array.of(1,2,3) the value of this within the inherited method will be %Int32Array%. Essentially the expression is explicitly naming the kind of typed array it wants to instantiate.

@@species is primarily for use in instance methods that create derived collections whose class isn't explicit stated at the usage site.