Skip to content

Pretty-print let-else with added parenthesization when needed #125051

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
May 13, 2024
Merged

Pretty-print let-else with added parenthesization when needed #125051

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
68854b7
Add AST pretty-printer tests for let-else
dtolnay May 12, 2024
94cc82c
Pretty-print let-else with added parenthesization when needed
dtolnay May 12, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
6 changes: 5 additions & 1 deletion compiler/rustc_ast_pretty/src/pprust/state.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1238,7 +1238,11 @@ impl<'a> State<'a> {
if let Some((init, els)) = loc.kind.init_else_opt() {
self.nbsp();
self.word_space("=");
self.print_expr(init, FixupContext::default());
self.print_expr_cond_paren(
init,
els.is_some() && classify::expr_trailing_brace(init).is_some(),
FixupContext::default(),
);
if let Some(els) = els {
self.cbox(INDENT_UNIT);
self.ibox(INDENT_UNIT);
Expand Down
15 changes: 15 additions & 0 deletions tests/ui/macros/stringify.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -675,6 +675,11 @@ fn test_stmt() {
"let (a, b): (u32, u32) = (1, 2);",
"let (a, b): (u32, u32) = (1, 2)"
);
c2!(stmt,
[ let _ = f() else { return; } ],
"let _ = f() else { return; };",
"let _ = f() else { return; }",
);
macro_rules! c2_let_expr_minus_one {
([ $expr:expr ], $stmt_expected:expr, $tokens_expected:expr $(,)?) => {
c2!(stmt, [ let _ = $expr - 1 ], $stmt_expected, $tokens_expected);
Expand All @@ -685,6 +690,16 @@ fn test_stmt() {
"let _ = match void {} - 1;",
"let _ = match void {} - 1",
);
macro_rules! c2_let_expr_else_return {
([ $expr:expr ], $stmt_expected:expr, $tokens_expected:expr $(,)?) => {
c2!(stmt, [ let _ = $expr else { return; } ], $stmt_expected, $tokens_expected);
};
}
c2_let_expr_else_return!(
[ f() ],
"let _ = f() else { return; };",
"let _ = f() else { return; }",
);
Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I initially tried testing this with:

    c2_let_expr_else_return!(
        [ loop {} ],
        "let _ = (loop {}) else { return; };",
        "let _ = loop {} else { return; }",
    );

but the curly brace diagnostic actually looks inside of the $expr. I am not sure whether that is intentional. (In my opinion it shouldn't do that.) I added a separate test in tests/ui/unpretty instead.

error: right curly brace `}` before `else` in a `let...else` statement not allowed
  --> tests/ui/macros/stringify.rs:704:17
   |
LL |         [ loop {} ],
   |                 ^
   |
help: wrap the expression in parentheses
   |
LL |         [ (loop {}) ],
   |           +       +


// StmtKind::Item
c1!(stmt, [ struct S; ], "struct S;");
Expand Down
0 tests/ui/unpretty/pretty-let-else.rs → tests/ui/unpretty/let-else-hir.rs
View file
Open in desktop
File renamed without changes.
0 tests/ui/unpretty/pretty-let-else.stdout → tests/ui/unpretty/let-else-hir.stdout
View file
Open in desktop
File renamed without changes.
11 changes: 11 additions & 0 deletions tests/ui/unpretty/let-else.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,11 @@
//@ compile-flags: -Zunpretty=expanded
//@ check-pass

macro_rules! expr {
($e:expr) => { $e };
}

fn main() {
let _ = expr!(1 + 1) else { return; };
let _ = expr!(loop {}) else { return; };
}
15 changes: 15 additions & 0 deletions tests/ui/unpretty/let-else.stdout
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,15 @@
#![feature(prelude_import)]
#![no_std]
#[prelude_import]
use ::std::prelude::rust_2015::*;
#[macro_use]
extern crate std;
//@ compile-flags: -Zunpretty=expanded
//@ check-pass

macro_rules! expr { ($e:expr) => { $e }; }

fn main() {
let _ = 1 + 1 else { return; };
let _ = (loop {}) else { return; };
}