Remove redundant ReturnIfAbrupt shorthands

[saschanaz]

See #1224

• At least two implementers are interested (and none opposed):
  • …
  • …
• Tests are written and can be reviewed and commented upon at:
  • …
• Implementation bugs are filed:
  • Chrome: …
  • Firefox: …
  • Safari: …
  • Deno: …
  • Node.js: …

(See WHATWG Working Mode: Changes for more details.)

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[saschanaz]

I'm doing this since I guess this shouldn't collide with #1224 (comment):

Or, we could try to further harmonize with the rest of the web spec ecosystem, and stop doing completion records entirely. (Except where necessary to interface with ECMAScript.) I think I'd kind of prefer that.

Just want to make sure this is in the right direction since I'm not super familiar with ReturnIfAbrupt. Especially:

Also, everything has a header saying what it returns.

Is this needed to do this cleanup?

@domenic

[domenic]

Yes, I think this is in in the right direction. Basically:

• Find all never-fail operations in the streams spec, and remove all !s from calls to them.

• Remove all !s from calls to ECMAScript operations that do not return abstract completions anymore. I believe the following list is comprehensive: CopyDataBlockBytes, CreateArrayFromList, CreateBuiltinFunction, IsDetachedBuffer, IsIntegralNumber (we need to update we're using IsInteger), OrdinaryObjectCreate, SameValue, Type.

I think we should be sure to do all of these at once, as otherwise it's a bit confusing.

Also, everything has a header saying what it returns.

Is this needed to do this cleanup?

I'm not sure; I welcome your input or that of the other editors.

Without the header, the situation is a bit confusing, because you can only know whether an abstract op returns a completion or a bare value by inspecting the call sites. (I.e., if all call sites use ?/!, it's a completion. If all do not, it's a bare value. If it's a mix, that's a spec bug.) It seems relatively easy to get confused.

However, it might be worth thinking about the world post-#1224, to avoid wasted effort. I'll comment over there with some ideas.