1377979 - Terminology: consider renaming fixed/reserved slots

Status: NEW

(Core :: JavaScript Engine, enhancement, P3)

Description

[Steve Fink [:sfink] [:s:]]

It is a longstanding nuisance to me that I am completely incapable of remembering what "fixed slots" and "reserved slots" mean. I *just* realized that "fixed" is so named because they live at a fixed offset from the JSObject pointer. Which feels to me like an implication of the main point, which is that they're allocated inline. And "reserved" always made me wonder "reserved for whom?" The JS engine? The embedding?

After discussing on IRC, my current leaning would be

  fixed -> inline
  reserved -> internal

I know we use "inline" for a number of different things, but I think it always means the same thing.

"internal" doesn't necessarily answer the engine vs embedding question (in fact, it implies that the embedding can *not* use them, if anything), but at least you know that the embedding gets to pass JSCLASS_HAS_INTERNAL_SLOTS(n) and that the distinction between these slots and other slots is whether they're internal or not. (As opposed to whether they are "reserved" or not, which means... something?)

Alternative possibilies for reserved: hidden/unnamed/nameless/anonymous

Sorry for the bikeshed, but I think this has slowed me down an uncomfortable amount over the years.