Editorial: "a function object" -> "an ECMAScript function object" #3144
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…c39#3144) ... in the declared type of parameters, returns, and record fields, where appropriate.
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…c39#3144) ... in the declared type of parameters, returns, and record fields, where appropriate.
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This PR narrows "a function object" to "an ECMAScript function object" where appropriate.
(This is an expansion of #3138 (comment).)
I've split it into 2 commits to make it a bit easier to follow the propagation of narrowing, but they can probably be squashed for merging.
commit 1: Creating an ECMAScript function object
OrdinaryFunctionCreate returns an ECMAScript function object (EFO).
(1)
So, every operation that returns the result of OrdinaryFunctionCreate (i.e., every operation that creates a function for a FunctionBody or similar) also returns an EFO:
and, going one further level up,
(2)
A Record field that only ever holds the result of OrdinaryFunctionCreate holds an EFO:
commit 2: Calling an ECMAScript function object
By definition, 10.2.1 [[Call]] and 10.2.2 [[Construct]] only operate on EFOs.
From this, we know the following are only invoked on EFOs:
And, from the last,
And from that,
And from those,
Downstream specs: The only downstream reference to any of these things is HTML's use of
OrdinaryFunctionCreate, and it doesn't care that we're narrowing the declared return type.