Factor out all ordinary object internal methods into OrdinaryXyz()?

[domenic]

HTML needs to specify a couple exotic objects. (Web IDL also needs to do so, if it ever gets updated to ES2015.) In many cases the behavior is "if flag X is set, throw. Otherwise, do what an ordinary object would do."

For a couple internal methods, there are pre-existing abstract operations we can use: OrdinaryGetOwnProperty and OrdinaryDefineOwnProperty. But for all others, there are not.

I see two potential ways we could spec such exotic objects:

1. Pull request ES to have OrdinaryXyz() abstract operation counterparts for all internal methods, and then use them: "If flag X is set, throw a TypeError. Otherwise, return OrdinarySetPrototypeOf(O, V)".
2. Try to come up with some phrasing that is sufficiently precise. E.g.: "If flag X is set, throw a TypeError. Otherwise, return the result of the same algorithm as the [SetOwnProperty] method for ordinary objects, applied to object O with argument V."

Any advice? Is there a chance (1) could clean up parts of the ES spec that are currently duplicated?

/cc @annevk @allenwb

[anba]

You could use the same language as in 9.4.4 Arguments Exotic Objects, for example:

Return the result of calling the default ordinary object [[SetPrototypeOf]] internal method (9.1.2) on O passing V as the argument.

[[Get]], [[Set]] and [[Delete]] for arguments objects use this wording to call the ordinary internal methods.

[anba]

You could use the same language as in 9.4.4 Arguments Exotic Objects, for example:

Return the result of calling the default ordinary object [[SetPrototypeOf]] internal method (9.1.2) on O passing V as the argument.

[[Get]], [[Set]] and [[Delete]] for arguments objects use this wording to call the ordinary internal methods.

[domenic]

I guess that covers it; thanks!

[domenic]

I guess that covers it; thanks!

[annevk]

Is there a reason ECMAScript uses both patterns?

[annevk]

Is there a reason ECMAScript uses both patterns?

[bterlson]

@annevk which patterns are you referring to?

[bterlson]

@annevk which patterns are you referring to?

[annevk]

What @anba mentioned and using OrdinaryInternalMethod abstract operations.

[annevk]

What @anba mentioned and using OrdinaryInternalMethod abstract operations.

[annevk]

Also, if I say use "default ordinary object [[Get]] internal method", does that mean the [[GetOwnProperty]] call it does (and similar ones) are the normal non-overridden variants as well?

[annevk]

Also, if I say use "default ordinary object [[Get]] internal method", does that mean the [[GetOwnProperty]] call it does (and similar ones) are the normal non-overridden variants as well?

[allenwb]

@annevk
Choice of how to do this is mostly a judgement call by the editor. delegating to OrdinaryX abstraction operation adds a level of indirection that make the normal case harder to read/understand. Using ""default ordinary object..." (and note a section reference is always included) only adds complexity at the "call site".

If you say "call the default ordinary object [[Get]] internal method" (and you need to include a section reference) you mean exactly and only that. If you say "call the [[GetOwnProperty internal method of obj" (or just say obj.[GetOwnProperty] ) you are going throw the meta-level dynamic dispatch to the specific [[GetOwnPrperty]] associated with obj.

[allenwb]

@annevk
Choice of how to do this is mostly a judgement call by the editor. delegating to OrdinaryX abstraction operation adds a level of indirection that make the normal case harder to read/understand. Using ""default ordinary object..." (and note a section reference is always included) only adds complexity at the "call site".

If you say "call the default ordinary object [[Get]] internal method" (and you need to include a section reference) you mean exactly and only that. If you say "call the [[GetOwnProperty internal method of obj" (or just say obj.[GetOwnProperty] ) you are going throw the meta-level dynamic dispatch to the specific [[GetOwnPrperty]] associated with obj.

[annevk]

It's still not clear that if you say "call the default ordinary object [[Get]] internal method" that means that the internal methods that that algorithm invokes, are also the default ordinary ones. At least not to me.

[annevk]

It's still not clear that if you say "call the default ordinary object [[Get]] internal method" that means that the internal methods that that algorithm invokes, are also the default ordinary ones. At least not to me.

[allenwb]

@annevk It is just referring to the internal methods specified in 9.1.

Arguably, the word "default" is redundant as any object that does not use the definitions in 9.1 is not an "ordinary object".

[allenwb]

@annevk It is just referring to the internal methods specified in 9.1.

Arguably, the word "default" is redundant as any object that does not use the definitions in 9.1 is not an "ordinary object".