Editorial: add description to Function Environment Records

[OnlyWick]

No description provided.

[jmdyck]

This resolves an inconsistency in the paragraph (that goes back to ES6), but I wonder if it should have gone the other way (adding "function" to the first occurrence)...

The phrase "the function is [not] an |ArrowFunction|" is technically a category error, since a function is an Object (a language value), whereas an |ArrowFunction| is a Parse Node (a spec value). Saying "an |ArrowFunction| function" avoids the category error, but isn't much clearer, because the spec doesn't define what "an |ArrowFunction| function" is. I imagine it's a function that was created by evaluating an |ArrowFunction| expression. But if we expect readers to fill in that gap, then maybe it's okay to expect them to make sense of the category-error version.

[OnlyWick]

@jmdyck You reminded me that function is an Object, which I didn't initially notice because I instinctively thought of ArrowFunction as a function type. That's why I considered the function word in an |ArrowFunction| function unnecessary. You mentioned that an |ArrowFunction| function can avoid a category error, so indeed, it would be better to include the word 'function' from the beginning, simply treating it as one of many types of functions.

[michaelficarra]

It's not even correct, there's also AsyncArrowFunction now.

[OnlyWick]

@michaelficarra Yeah, you're right. I can update it. :-)

15.3.4 Runtime Semantics: InstantiateArrowFunctionExpression
...
5. Let closure be OrdinaryFunctionCreate(%Function.prototype%, sourceText, ArrowParameters, ConciseBody, lexical-this, env, privateEnv).
...

15.9.4 Runtime Semantics: InstantiateAsyncArrowFunctionExpression
...
6. Let closure be OrdinaryFunctionCreate(%AsyncFunction.prototype, sourceText, parameters, AsyncConciseBody, lexical-this, env, privateEnv).
...

[OnlyWick]

About this sentence: If a function is not an ArrowFunction function and references super, I need some time to explore whether it needs to include AsyncArrowFunction. lol

[OnlyWick]

@michaelficarra And, [[ThisBindingStatus]]: If the value is lexical, this is an ArrowFunction and does not have a local this value. also missing AsyncArrowFunction. I will update it later.

[OnlyWick]

If a function is not an |ArrowFunction| function and references super also missing AsyncArrowFunction.

The super Keyword RS: Evaluation and MakeSuperPropertyReference ( actualThis, propertyKey, strict ) always have below step,

• Let env be GetThisEnvironment().

If use ArrowFunction or AsyncArrowFunction, it need to go through 9.4.3 GetThisEnvironment( ) find correct state.

[OnlyWick]

Already update it, @jmdyck @michaelficarra Can you review it?