Editorial: String.prototype.matchAll iterators won't return null

[susisu]

Description:

The description of String.prototype.matchAll says:

Each iteration result's value is an Array containing the results of the match, or null if the String did not match.

However, if the string did not match, the iterator returns undefined, not null, as far as you don't use an object with a custom @@matchAll property instead of the standard RegExp.

(Possibly this is because the old reivision of the proposal stated it returns null but the description remains unchanged?)

eshost Output:

$ eshost -s -x "const it = 'A'.matchAll(/B/g); const r = it.next(); print(r.done); print(r.value)"
#### JavaScriptCore, SpiderMonkey, V8, V8 --harmony, XS
true
undefined

[ljharb]

In the case where done is true, the value should be ignored, so i think we just need to tweak the description and remove the last clause.