Improve parsing of labeled loop as value expression for break #1531

dtolnay · 2023-11-06T01:11:43Z

Before:

error: unexpected token, expected `;`
 --> dev/main.rs:9:21
  |
9 |         break 'label: loop { break 'label 42; };
  |                     ^

After:

error: parentheses required
 --> dev/main.rs:9:15
  |
9 |         break 'label: loop { break 'label 42; };
  |               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

warning: for loop over a single element --> tests/test_expr.rs:333:5 | 333 | / for stmt in [ 334 | | // Parentheses required. See rust-lang/rust#87026. 335 | | quote! { 336 | | break 'label: loop { break 'label 42; }; ... | 339 | | syn::parse2::<Stmt>(stmt).unwrap_err(); 340 | | } | |_____^ | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_element_loop = note: `-W clippy::single-element-loop` implied by `-W clippy::all` = help: to override `-W clippy::all` add `#[allow(clippy::single_element_loop)]` help: try | 333 ~ { 334 + let stmt = { 335 + let mut _s = $crate::__private::TokenStream::new(); 336 + $crate::quote_each_token!{_s $($tt)*} 337 + _s 338 + }; 339 + syn::parse2::<Stmt>(stmt).unwrap_err(); 340 + } |

dtolnay added 3 commits November 5, 2023 17:08

Add test of ambiguous label parsing in break

32ab979

Improve error on break followed by labeled loop

a876185

dtolnay merged commit 95aeeb5 into master Nov 6, 2023

dtolnay deleted the breaklabel branch November 6, 2023 01:23

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Improve parsing of labeled loop as value expression for break #1531

Improve parsing of labeled loop as value expression for break #1531

dtolnay commented Nov 6, 2023

Improve parsing of labeled loop as value expression for break #1531

Improve parsing of labeled loop as value expression for break #1531

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dtolnay commented Nov 6, 2023