feat: Implement thin-arrow completion in fn return position by A4-Tacks · Pull Request #21012 · rust-lang/rust-analyzer

A4-Tacks · 2025-11-10T12:46:03Z

Very cool feature that can quickly complete simple return types

Close #20885

Example

fn foo() u$0

Before this PR

kw where

After this PR

bt u32 (adds ->) u32
kw where
...

fn foo() -> u32

A4-Tacks · 2025-12-15T13:04:18Z

r? @ChayimFriedman2

ChayimFriedman2 · 2026-04-06T06:18:38Z

+        match ret_type.ty() {
+            Some(ast::Type::PathType(path_ty)) => {
+                path_ty.path().is_some_and(|path| path.as_single_name_ref().is_some())
+            }
+            Some(_) => false,
+            None => true,
+        }


Why is this? Is there a problem completing an arrow on e.g. fn foo() bar::baz| {}?

Usually, arrows are completed when input bar

Moreover, when completing foo::bar, the range is bar instead of foo::bar, so adding arrows before requires TextEdit, which is a bit troublesome

You can add the arrow after the ).

So this requires TextEdit, but using TextEdit seems to be a good solution as well

ChayimFriedman2 · 2026-04-06T06:22:56Z

+fn x() u$0
+"#,
+        expect![[r#"
+            en Enum                    Enum


IMO we should visibly render the -> in the label.

This is difficult to complete, the editor needs to make the matching skip the arrow

Did you mean to comment on my other comment?

No

fo foo ^^

Better than this:

fo -> foo ^^

Some editors do not even support such completion

The label can be whatever we want.

But the editor will use the current input to match the label, and the strange prefix makes it difficult to match

CompletionItem::lookup can control the filtering.

Another question, if the label has an arrow, it can sometimes be strange:

mod foo {} fn bar() foo::bar$0 {}

Outputs label -> bar, but complete bar, this is a bit counterintuitive

Perhaps you can refer to auto import, outputs label bar(adds ->)

Right, that's better.

Very cool feature that can quickly complete simple return types Example --- ```rust fn foo() u$0 ``` **Before this PR** ```text kw where ``` **After this PR** ```text bt u32 (adds ->) u32 kw where ... ``` ```rust fn foo() -> u32 ```

rustbot · 2026-04-06T11:08:16Z

This PR was rebased onto a different master 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.

rustbot added the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Nov 10, 2025

A4-Tacks force-pushed the comp-ret-type-arrow branch from 75387d9 to e7bc867 Compare November 10, 2025 13:24

A4-Tacks requested a review from ChayimFriedman2 November 11, 2025 11:17

marcoieni force-pushed the master branch from 2efc800 to c826519 Compare November 18, 2025 11:05

A4-Tacks mentioned this pull request Nov 19, 2025

Request to review some old PRs #21067

Closed

41 tasks

rustbot assigned ChayimFriedman2 Dec 15, 2025

A4-Tacks force-pushed the comp-ret-type-arrow branch from e7bc867 to 3f1b4ba Compare December 30, 2025 02:04

A4-Tacks mentioned this pull request Dec 30, 2025

Complete thin-arrow on function return position #20885

Closed

A4-Tacks force-pushed the comp-ret-type-arrow branch from 3f1b4ba to fdc2bee Compare January 29, 2026 14:37

ChayimFriedman2 reviewed Apr 6, 2026

View reviewed changes

A4-Tacks changed the title ~~Implement thin-arrow completion in fn return position~~ feat: Implement thin-arrow completion in fn return position Apr 6, 2026

A4-Tacks added 4 commits April 6, 2026 19:05

Add optional thin-arrow ret-type for fn-item

541ac32

Add adds_text to completion item builder

437b0ce

Implement thin-arrow completion in fn return position

c4898ee

Very cool feature that can quickly complete simple return types Example --- ```rust fn foo() u$0 ``` **Before this PR** ```text kw where ``` **After this PR** ```text bt u32 (adds ->) u32 kw where ... ``` ```rust fn foo() -> u32 ```

Remove a ide-typing test

1569397

A4-Tacks force-pushed the comp-ret-type-arrow branch from fdc2bee to 1569397 Compare April 6, 2026 11:08

A4-Tacks requested a review from ChayimFriedman2 April 6, 2026 11:23

ChayimFriedman2 approved these changes Apr 6, 2026

View reviewed changes

ChayimFriedman2 added this pull request to the merge queue Apr 6, 2026

Merged via the queue into rust-lang:master with commit 09ae159 Apr 6, 2026
17 checks passed

rustbot removed the S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. label Apr 6, 2026

A4-Tacks deleted the comp-ret-type-arrow branch April 7, 2026 06:33

A4-Tacks mentioned this pull request Apr 7, 2026

minor: Fix self kw is snippet in type location #21982

Merged

A4-Tacks mentioned this pull request Apr 23, 2026

fix: no complete where kw after qualified path #22154

Merged

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A4-Tacks commented Nov 10, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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A4-Tacks commented Dec 15, 2025

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rustbot commented Apr 6, 2026

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A4-Tacks commented Nov 10, 2025 •

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