Suggests turbofish in patterns #114300

mu001999 · 2023-07-31T18:04:04Z

Fixes #114112

r? @estebank

compiler/rustc_parse/src/parser/path.rs

compiler/rustc_parse/src/parser/pat.rs

tests/ui/did_you_mean/issue-114112.stderr

mu001999 · 2023-08-01T08:09:02Z

r? @compiler-errors

compiler/rustc_parse/src/parser/path.rs

tests/ui/suggestions/issue-64252-self-type.stderr

estebank

If we can manage to keep the suggestion for wrong arbitrary self types that I highlighted, the current approach should work.

mu001999 · 2023-08-02T16:02:57Z

@estebank The new commit keeps the suggestions for wrong arbitrary self types that you highlighted. Please review again, thanks! ;)

rustbot · 2023-08-02T16:14:04Z

Some changes occurred in src/tools/rustfmt

cc @rust-lang/rustfmt

compiler/rustc_parse/src/parser/pat.rs

estebank · 2023-08-02T17:05:45Z

tests/ui/anon-params/anon-params-denied-2018.stderr

+help: if this is a `self` type, give it a parameter name
+   |
+LL |     fn foo_with_qualified_path(self: <Bar as T>::Baz);
+   |                                +++++


Mmm... Arbitrary self types only support a handful of pointer types (Box, Arc, Rc). General arbitrary self types are unlikely to be supported any time soon, so adding this suggestion would be confusing to users. (I know, I know, but we have to try to minimize confusion to users, the only thing worse than an error without a suggestion is an error with a wrong suggestion.)

As mentioned below (#114300 (comment))

estebank · 2023-08-02T17:07:02Z

tests/ui/parser/issues/issue-22647.rs

@@ -1,5 +1,5 @@
 fn main() {
-    let caller<F> = |f: F|  //~ ERROR expected one of `:`, `;`, `=`, `@`, or `|`, found `<`
+    let caller<F> = |f: F|  //~ ERROR generic args in patterns require the turbofish syntax


Looking at this error, the suggestion we should be giving is to add a type, but don't know how hard it would be to change.

Like function parameters, maybe we can also suggest name: caller<F> or _: caller<F>? I think it may be more general, because caller<F> is more like a type.

Yeah, I think the later is the better suggestion (particularly if the rest can be parsed as a type until ; or = is reached).

estebank · 2023-08-02T17:08:14Z

tests/ui/span/issue-34264.stderr

  --> $DIR/issue-34264.rs:1:14
   |
 LL | fn foo(Option<i32>, String) {}
-   |              ^ expected one of `:`, `@`, or `|`
+   |              ^ expected one of 9 possible tokens
   |
   = note: anonymous parameters are removed in the 2018 edition (see RFC 1685)
 help: if this is a `self` type, give it a parameter name


Oh, I see that we already provide a bad arbitrary self type suggestion :-/

Yes, and I think we can't emit suggestions only for pointer types in the parsing stage, since we can use type alias type P<T> = Box<T>. So I think this is acceptable and the current behaviour extends the old arbitrary self type suggestions.

estebank · 2023-08-02T17:11:47Z

compiler/rustc_parse/src/parser/diagnostics.rs

@@ -1579,7 +1579,7 @@ impl<'a> Parser<'a> {
        self.expect(&token::ModSep)?;

        let mut path = ast::Path { segments: ThinVec::new(), span: DUMMY_SP, tokens: None };
-        self.parse_path_segments(&mut path.segments, T::PATH_STYLE, None)?;
+        self.parse_path_segments(&mut path.segments, T::PATH_STYLE, None, None)?;


I'm not super happy with the proliferation of Nones this causes, but I also don't have much of a better proposal (short of having a *_with_pat_location family of methods).

The new changes reduce the Nones, but there are still some (seemingly unavoidable at the moment)

estebank · 2023-08-02T17:13:14Z

tests/ui/span/issue-34264.stderr

@@ -1,8 +1,8 @@
-error: expected one of `:`, `@`, or `|`, found `<`
+error: expected one of `!`, `(`, `...`, `..=`, `..`, `::`, `:`, `{`, or `|`, found `<`


If we can, I'd like to revert whatever causes this message change, as I feel the previous one did a good job leading people towards the problem of a missing :

This is reverted now! ;)

estebank · 2023-08-03T12:47:57Z

@bors r+

bors · 2023-08-03T12:47:59Z

📌 Commit dce7e87 has been approved by estebank

It is now in the queue for this repository.

…bank Suggests turbofish in patterns Fixes rust-lang#114112 r? `@estebank`

…bank Suggests turbofish in patterns Fixes rust-lang#114112 r? ``@estebank``

…iaskrgr Rollup of 8 pull requests Successful merges: - rust-lang#113657 (Expand, rename and improve `incorrect_fn_null_checks` lint) - rust-lang#114237 (parser: more friendly hints for handling `async move` in the 2015 edition) - rust-lang#114300 (Suggests turbofish in patterns) - rust-lang#114372 (const validation: point at where we found a pointer but expected an integer) - rust-lang#114395 ([rustc_span][perf] Hoist lookup sorted by words out of the loop.) - rust-lang#114403 (fix the span in the suggestion of remove question mark) - rust-lang#114408 (Temporary remove myself from review rotation) - rust-lang#114415 (Skip checking of `rustc_codegen_gcc` with vendoring enabled) r? `@ghost` `@rustbot` modify labels: rollup

…bank Suggests turbofish in patterns Fixes rust-lang#114112 r? ```@estebank```

rustbot assigned estebank Jul 31, 2023

rustbot added S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. T-compiler Relevant to the compiler team, which will review and decide on the PR/issue. labels Jul 31, 2023

This comment has been minimized.

Sign in to view

compiler-errors reviewed Jul 31, 2023

View reviewed changes

compiler/rustc_parse/src/parser/path.rs Outdated Show resolved Hide resolved

compiler/rustc_parse/src/parser/pat.rs Outdated Show resolved Hide resolved

tests/ui/did_you_mean/issue-114112.stderr Outdated Show resolved Hide resolved

mu001999 force-pushed the fix/turbofish-pat branch 2 times, most recently from b60f7bb to 7146f92 Compare August 1, 2023 08:08

rustbot assigned compiler-errors and unassigned estebank Aug 1, 2023

This comment has been minimized.

Sign in to view

mu001999 force-pushed the fix/turbofish-pat branch from 7146f92 to 326e61a Compare August 1, 2023 12:43

estebank reviewed Aug 1, 2023

View reviewed changes

compiler/rustc_parse/src/parser/path.rs Outdated Show resolved Hide resolved

Suggests turbofish in patterns

049c728

mu001999 force-pushed the fix/turbofish-pat branch from 326e61a to 049c728 Compare August 1, 2023 15:30

mu001999 requested review from estebank and compiler-errors August 1, 2023 15:46

estebank reviewed Aug 2, 2023

View reviewed changes

tests/ui/suggestions/issue-64252-self-type.stderr Outdated Show resolved Hide resolved

estebank approved these changes Aug 2, 2023

View reviewed changes

Keep the suggestion for wrong arbitrary self types

89b2fe7

mu001999 requested a review from estebank August 2, 2023 16:01

This comment has been minimized.

Sign in to view

Fix rustfmt dep

f5243d2

estebank reviewed Aug 2, 2023

View reviewed changes

mu001999 added 3 commits August 3, 2023 05:18

Apply suggestions

41e85c3

Avoid too many expected symbols and reduce Nones

8c8af6c

Reduce arbitrary self type suggestions

dce7e87

mu001999 force-pushed the fix/turbofish-pat branch from 25264ee to dce7e87 Compare August 3, 2023 10:35

mu001999 requested a review from estebank August 3, 2023 10:41

bors added S-waiting-on-bors Status: Waiting on bors to run and complete tests. Bors will change the label on completion. and removed S-waiting-on-review Status: Awaiting review from the assignee but also interested parties. labels Aug 3, 2023

matthiaskrgr added a commit to matthiaskrgr/rust that referenced this pull request Aug 3, 2023

Rollup merge of rust-lang#114300 - MU001999:fix/turbofish-pat, r=este…

09a086e

…bank Suggests turbofish in patterns Fixes rust-lang#114112 r? `@estebank`

matthiaskrgr mentioned this pull request Aug 3, 2023

Rollup of 7 pull requests #114419

Closed

matthiaskrgr added a commit to matthiaskrgr/rust that referenced this pull request Aug 3, 2023

Rollup merge of rust-lang#114300 - MU001999:fix/turbofish-pat, r=este…

17e9111

…bank Suggests turbofish in patterns Fixes rust-lang#114112 r? ``@estebank``

This was referenced Aug 3, 2023

Rollup of 8 pull requests #114421

Closed

Rollup of 8 pull requests #114424

Merged

bors merged commit 51d1dac into rust-lang:master Aug 3, 2023
11 checks passed

rustbot added this to the 1.73.0 milestone Aug 3, 2023

mu001999 deleted the fix/turbofish-pat branch August 4, 2023 02:27

This was referenced Sep 12, 2023

regression: generic args in patterns require the turbofish syntax #115780

Closed

Only suggest turbofish in patterns if we may recover #115785

Merged

calebcartwright pushed a commit to calebcartwright/rust that referenced this pull request Oct 23, 2023

Rollup merge of rust-lang#114300 - MU001999:fix/turbofish-pat, r=este…

2c8cc96

…bank Suggests turbofish in patterns Fixes rust-lang#114112 r? ```@estebank```

calebcartwright pushed a commit to calebcartwright/rust that referenced this pull request Jun 22, 2024

Rollup merge of rust-lang#114300 - MU001999:fix/turbofish-pat, r=este…

4cc22af

…bank Suggests turbofish in patterns Fixes rust-lang#114112 r? ```@estebank```

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Suggests turbofish in patterns #114300

Suggests turbofish in patterns #114300

mu001999 commented Jul 31, 2023

This comment has been minimized.

mu001999 commented Aug 1, 2023

This comment has been minimized.

estebank left a comment

mu001999 commented Aug 2, 2023 •

edited

Loading

This comment has been minimized.

rustbot commented Aug 2, 2023

estebank Aug 2, 2023

mu001999 Aug 3, 2023

estebank Aug 2, 2023

mu001999 Aug 3, 2023

estebank Aug 3, 2023

estebank Aug 2, 2023

mu001999 Aug 3, 2023 •

edited

Loading

estebank Aug 2, 2023

mu001999 Aug 3, 2023

estebank Aug 2, 2023

mu001999 Aug 3, 2023

estebank commented Aug 3, 2023

bors commented Aug 3, 2023

		@@ -1,8 +1,8 @@
		error: expected one of `:`, `@`, or `\|`, found `<`
		error: expected one of `!`, `(`, `...`, `..=`, `..`, `::`, `:`, `{`, or `\|`, found `<`

Suggests turbofish in patterns #114300

Suggests turbofish in patterns #114300

Conversation

mu001999 commented Jul 31, 2023

This comment has been minimized.

mu001999 commented Aug 1, 2023

This comment has been minimized.

estebank left a comment

Choose a reason for hiding this comment

mu001999 commented Aug 2, 2023 • edited Loading

This comment has been minimized.

rustbot commented Aug 2, 2023

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

mu001999 Aug 3, 2023 • edited Loading

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

Choose a reason for hiding this comment

estebank commented Aug 3, 2023

bors commented Aug 3, 2023

mu001999 commented Aug 2, 2023 •

edited

Loading

mu001999 Aug 3, 2023 •

edited

Loading