diff --git a/src/doc/style-guide/src/editions.md b/src/doc/style-guide/src/editions.md index 19e62c4867c99..b9a89c20cee40 100644 --- a/src/doc/style-guide/src/editions.md +++ b/src/doc/style-guide/src/editions.md @@ -36,6 +36,10 @@ For a full history of changes in the Rust 2024 style edition, see the git history of the style guide. Notable changes in the Rust 2024 style edition include: +- [#114764](https://github.com/rust-lang/rust/pull/114764) As the last member + of a delimited expression, delimited expressions are generally combinable, + regardless of the number of members. Previously only applied with exactly + one member (except for closures with explicit blocks). - Miscellaneous `rustfmt` bugfixes. - Use version-sort (sort `x8`, `x16`, `x32`, `x64`, `x128` in that order). - Change "ASCIIbetical" sort to Unicode-aware "non-lowercase before lowercase". diff --git a/src/doc/style-guide/src/expressions.md b/src/doc/style-guide/src/expressions.md index 12037b5992ec0..171a24cd89d73 100644 --- a/src/doc/style-guide/src/expressions.md +++ b/src/doc/style-guide/src/expressions.md @@ -818,11 +818,11 @@ E.g., `&&Some(foo)` matches, `Foo(4, Bar)` does not. ## Combinable expressions -Where a function call has a single argument, and that argument is formatted -across multiple-lines, format the outer call as if it were a single-line call, +When the last argument in a function call is formatted across +multiple-lines, format the outer call as if it were a single-line call, if the result fits. Apply the same combining behaviour to any similar expressions which have multi-line, block-indented lists of sub-expressions -delimited by parentheses (e.g., macros or tuple struct literals). E.g., +delimited by parentheses, brackets, or braces. E.g., ```rust foo(bar( @@ -848,20 +848,61 @@ let arr = [combinable( an_expr, another_expr, )]; + +let x = Thing(an_expr, another_expr, match cond { + A => 1, + B => 2, +}); + +let x = format!("Stuff: {}", [ + an_expr, + another_expr, +]); + +let x = func(an_expr, another_expr, SomeStruct { + field: this_is_long, + another_field: 123, +}); ``` Apply this behavior recursively. -For a function with multiple arguments, if the last argument is a multi-line -closure with an explicit block, there are no other closure arguments, and all -the arguments and the first line of the closure fit on the first line, use the -same combining behavior: +If the last argument is a multi-line closure with an explicit block, +only apply the combining behavior if there are no other closure arguments. ```rust +// Combinable foo(first_arg, x, |param| { action(); foo(param) }) +// Not combinable, because the closure is not the last argument +foo( + first_arg, + |param| { + action(); + foo(param) + }, + whatever, +) +// Not combinable, because the first line of the closure does not fit +foo( + first_arg, + x, + move |very_long_param_causing_line_to_overflow| -> Bar { + action(); + foo(param) + }, +) +// Not combinable, because there is more than one closure argument +foo( + first_arg, + |x| x.bar(), + |param| { + action(); + foo(param) + }, +) ``` ## Ranges