Editorial: Consistify summaries for instrinsic functions

[jmdyck]

(This recent comment from @michaelficarra reminded me of this old comment from me. It didn't get any discussion at the time (it wasn't crucial to the PR), so I'm raising it again in a dedicated issue.)

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There's an inconsistency in the prose for intrinsic functions that might have been within the scope of PR #2592, but I didn't do anything about it there because I wasn't sure how to resolve it. When a function definition includes a prose summary, it's sometimes a <p>, and sometimes an <emu-note>. The ones that are Notes are mainly in String.prototype.* and Array.prototype.*.

For example,

• String.p.charCodeAt has a summary-in-a-Note,
• String.p.matchAll has a summary-in-a-p.
• Array.prototype.copyWithin has a summary-in-a-Note (actually 2 Notes),
• Array.prototype.concat has a summary-in-a-p.

It looks like the summaries-as-Notes arose in ES6. The old ecmascript.org wiki says:

We generally within the specification try to minimize tutorial material (eg examples) and redundancy between normative prose descriptions and normative algorithms. Redundant descriptions has historically resulted in internal inconsistencies. We have also seen cases where implementors follow incomplete prose descriptions without referring to the more complete algorithm. For these reasons, much of the redundant prose from previous editions is being converted into non-normative notes.

My guess is that this was written by @allenwb, and refers to the summaries-as-notes we see in String.p.* and Array.p.*.

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Here are some possible actions:

• Leave it as is. (Maybe resolve it later.)
• Change all the <emu-note> summaries to <p> summaries.
• Change all the <p> summaries to <emu-note> summaries.
• Change all summaries to something different. (e.g., <p class="summary"> or <div class="summary">. It could get some distinctive styling and we could explain its status in the frontmatter.)
• Delete all summaries.

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There's a related oddity that sometimes a summary-as-Note appears after the <emu-alg>.
E.g.

• String.p.endsWith
• String.p.includes

We could easily move these up, but it's maybe not worth it until we have a solution to the Note-vs-p problem.

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Personally, I think we should mark summaries with something like class="summary", style them differently, and say (probably in 18 "ECMAScript Standard Built-in Objects") that they're imprecise, incomplete, and non-normative.