rustdoc: notable trait badge and popover enhancements by notriddle · Pull Request #160370 · rust-lang/rust

notriddle · 2026-08-02T06:54:02Z

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Part of #45040

Preview

https://notriddle.com/rustdoc-html-demo-13/gui-tests/lib2/notable_trait_colors/struct.NotableTraitColors.html

Screenshots

rustbot · 2026-08-02T06:54:06Z

Some changes occurred in GUI tests.

cc @GuillaumeGomez

Some changes occurred in HTML/CSS/JS.

cc @GuillaumeGomez, @lolbinarycat

Some changes occurred in compiler/rustc_attr_parsing

cc @jdonszelmann, @JonathanBrouwer

Some changes occurred in compiler/rustc_hir/src/attrs

cc @jdonszelmann, @JonathanBrouwer

rustbot · 2026-08-02T06:54:07Z

r? @petrochenkov

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GuillaumeGomez · 2026-08-02T10:33:43Z

-	--notable-badge-pink: oklch(0.88 0.21 0);
-	--notable-badge-red: oklch(0.88 0.21 40);
-	--notable-badge-orange: oklch(0.88 0.21 70);
+	--notable-badge-grey: oklch(0.88 0 0);


We're now switching to 8 colors?

View changes since the review

I can’t find it in the meeting minutes, but I remember mentioning the possibility of using the ANSI 3-bit color pallet, because it makes both directions of interop easier:

terminal apps like rusty-man can display these colors without requiring their own bespoke color theming system

anyone adding new themes to rustdoc-html can easily use a terminal color theme as a starting point

Fine by me!

GuillaumeGomez · 2026-08-02T11:34:44Z

+    border-color: #0f1419;
+  }
+  /* https://github.com/rust-lang/rust/pull/91480 */
+  .notabletrait-badge.light.grey {


I'm really not sure it's worth it to show people how to add their own colors.

View changes since the review

I kept the list, but got rid of the examples.

GuillaumeGomez · 2026-08-02T11:36:59Z

-	--notable-badge-violet: oklch(0.88 0.21 300);
+	--notable-badge-magenta: oklch(0.88 0.21 320);
+	--notable-badge-cyan: oklch(0.88 0.21 180);
+	--notable-badge-transparent: white;


I don't think having text floating around is a good idea, especially when it's a color picked by rustdoc automatically...

View changes since the review

petrochenkov · 2026-08-02T11:45:11Z

r? @GuillaumeGomez

Co-authored-by: Guillaume Gomez <contact@guillaume-gomez.fr>

rustbot · 2026-09-19T02:42:07Z

Some changes occurred in compiler/rustc_attr_ir

cc @jdonszelmann, @JonathanBrouwer

rustbot · 2026-09-19T02:42:09Z

This PR was rebased onto a different main commit. Here's a range-diff highlighting what actually changed.

Rebasing is a normal part of keeping PRs up to date, so no action is needed—this note is just to help reviewers.

Add test cases, and the same detailed info block that you get for return position notable traits.

notriddle · 2026-09-19T02:51:00Z

@GuillaumeGomez @ThierryBerger

I've done some tweaks to take into account feedback from these discussions, plus a few things I noticed while looking around the standard library:

The popover is now part of the notable traits row. If the notable trait is only implemented for certain generics, or if it has an associated type, you can see it in there. Also, it says "Notable traits" inside the popup, so there's at least something that tells you where this list comes from.
The padding and border radius is returned to what the original version used. The left edge of the notable trait badges are aligned with the left edge of the top-doc.
The "transparent" color badges now have a border, so they aren't just floating text with nothing around them.
The colored badges aren't in the docs any more. Just a list of color names.
Formatting fixes: added missing indent to the template, use From instead of Into for the conversion, and using "badge" consistently.

This still produces the feature gate error, so it's fine, but it also produces the "trait attribute" warning

GuillaumeGomez · 2026-09-19T20:47:49Z

+                return;
+            };
+            let Some(notable_trait_color) = notable_trait_color.value_as_str() else {
+                cx.emit_lint(INVALID_DOC_ATTRIBUTES, InvalidNotableTraitAttr, span);


Would be nice to give some extra info because they all emit the same lint with the same span. Or was it on purpose while waiting for team's approval?

View changes since the review

I figured that sort of thing could be handled in a follow-up, after we decide on the syntax we want at all.

Then add a fixme comment and open an issue.

GuillaumeGomez · 2026-09-19T20:53:24Z

When we hover the i, it gets underline decoration:

Also, not sure if I like it or not. I think we'll need to discuss with the rest of the team too (at least front-end).

GuillaumeGomez · 2026-09-20T08:52:54Z

Looks good to me, thanks! Let's ping the rest of the front-end members.

cc @rust-lang/rustdoc-frontend. This is making some changes to he display of notable traits. In particular, it adds the i alongside the badges and I'm not sure it's a good idea so I'd like everyone's opinion.

lolbinarycat · 2026-09-20T16:14:19Z

+    fn from(color: NotableTraitColor) -> &'static str {
+        use NotableTraitColor::*;
+        match color {
+            Grey => "grey",


do we want to support both spellings of gray/grey? if not, i believe "gray" is the more common in US english, which is what rustdoc uses (otherwise this would be colour)

View changes since the review

I thought gray was only a name until now. I'd been in favour of only using grey, as for foreigners, it's how we learn the color name (or colour :p).

lolbinarycat · 2026-09-20T16:16:55Z

This is an implementation of the earlier idea proposed by the bevy people that integrates more tightly with notable_trait instead of being its own thing, right? i'm definitely in favor of the notable_trait integration, if we are going to do this.

GuillaumeGomez · 2026-09-20T16:54:32Z

An extension. Can be compared with the existing: https://doc.rust-lang.org/nightly/std/fs/struct.File.html

rustbot assigned petrochenkov Aug 2, 2026

notriddle removed T-rustdoc Relevant to the rustdoc team, which will review and decide on the PR/issue. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. T-libs Relevant to the library team, which will review and decide on the PR/issue. labels Aug 2, 2026