Skip to content
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

Allow any identifier as format arg name #66847

Merged
merged 1 commit into from
Nov 30, 2019
Merged

Allow any identifier as format arg name #66847

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
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
33 changes: 17 additions & 16 deletions src/libfmt_macros/lib.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -442,20 +442,9 @@ impl<'a> Parser<'a> {
Some(ArgumentIs(i))
} else {
match self.cur.peek() {
Some(&(_, c)) if c.is_alphabetic() => {
Some(&(_, c)) if rustc_lexer::is_id_start(c) => {
Some(ArgumentNamed(Symbol::intern(self.word())))
}
Some(&(pos, c)) if c == '_' => {
let invalid_name = self.string(pos);
self.err_with_note(format!("invalid argument name `{}`", invalid_name),
"invalid argument name",
"argument names cannot start with an underscore",
self.to_span_index(pos).to(
self.to_span_index(pos + invalid_name.len())
),
);
Some(ArgumentNamed(Symbol::intern(invalid_name)))
},

// This is an `ArgumentNext`.
// Record the fact and do the resolution after parsing the
Expand Down Expand Up @@ -611,22 +600,34 @@ impl<'a> Parser<'a> {
/// Rust identifier, except that it can't start with `_` character.
fn word(&mut self) -> &'a str {
let start = match self.cur.peek() {
Some(&(pos, c)) if c != '_' && rustc_lexer::is_id_start(c) => {
Some(&(pos, c)) if rustc_lexer::is_id_start(c) => {
self.cur.next();
pos
}
_ => {
return &self.input[..0];
return "";
}
};
let mut end = None;
while let Some(&(pos, c)) = self.cur.peek() {
if rustc_lexer::is_id_continue(c) {
self.cur.next();
} else {
return &self.input[start..pos];
end = Some(pos);
break;
Copy link
Member Author

Choose a reason for hiding this comment

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

break-with-value in while-loops when?

}
}
&self.input[start..self.input.len()]
let end = end.unwrap_or(self.input.len());
let word = &self.input[start..end];
if word == "_" {
self.err_with_note(
"invalid argument name `_`",
"invalid argument name",
"argument name cannot be a single underscore",
self.to_span_index(start).to(self.to_span_index(end)),
);
}
word
}

/// Optionally parses an integer at the current position. This doesn't deal
Expand Down
6 changes: 4 additions & 2 deletions src/test/ui/fmt/format-string-error.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,10 +6,12 @@ fn main() {
println!("{{}}");
println!("}");
//~^ ERROR invalid format string: unmatched `}` found
let _ = format!("{_foo}", _foo = 6usize);
//~^ ERROR invalid format string: invalid argument name `_foo`
let _ = format!("{_}", _ = 6usize);
//~^ ERROR invalid format string: invalid argument name `_`
let _ = format!("{a:_}", a = "", _ = 0);
//~^ ERROR invalid format string: invalid argument name `_`
let _ = format!("{a:._$}", a = "", _ = 0);
//~^ ERROR invalid format string: invalid argument name `_`
let _ = format!("{");
//~^ ERROR invalid format string: expected `'}'` but string was terminated
let _ = format!("}");
Expand Down
44 changes: 26 additions & 18 deletions src/test/ui/fmt/format-string-error.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -16,24 +16,32 @@ LL | println!("}");
|
= note: if you intended to print `}`, you can escape it using `}}`

error: invalid format string: invalid argument name `_foo`
error: invalid format string: invalid argument name `_`
--> $DIR/format-string-error.rs:9:23
|
LL | let _ = format!("{_foo}", _foo = 6usize);
| ^^^^ invalid argument name in format string
LL | let _ = format!("{_}", _ = 6usize);
| ^ invalid argument name in format string
|
= note: argument names cannot start with an underscore
= note: argument name cannot be a single underscore

error: invalid format string: invalid argument name `_`
--> $DIR/format-string-error.rs:11:23
--> $DIR/format-string-error.rs:11:25
|
LL | let _ = format!("{_}", _ = 6usize);
| ^ invalid argument name in format string
LL | let _ = format!("{a:_}", a = "", _ = 0);
| ^ invalid argument name in format string
|
= note: argument name cannot be a single underscore

error: invalid format string: invalid argument name `_`
--> $DIR/format-string-error.rs:13:26
|
LL | let _ = format!("{a:._$}", a = "", _ = 0);
| ^ invalid argument name in format string
|
= note: argument names cannot start with an underscore
= note: argument name cannot be a single underscore

error: invalid format string: expected `'}'` but string was terminated
--> $DIR/format-string-error.rs:13:23
--> $DIR/format-string-error.rs:15:23
|
LL | let _ = format!("{");
| -^ expected `'}'` in format string
Expand All @@ -43,15 +51,15 @@ LL | let _ = format!("{");
= note: if you intended to print `{`, you can escape it using `{{`

error: invalid format string: unmatched `}` found
--> $DIR/format-string-error.rs:15:22
--> $DIR/format-string-error.rs:17:22
|
LL | let _ = format!("}");
| ^ unmatched `}` in format string
|
= note: if you intended to print `}`, you can escape it using `}}`

error: invalid format string: expected `'}'`, found `'\'`
--> $DIR/format-string-error.rs:17:23
--> $DIR/format-string-error.rs:19:23
|
LL | let _ = format!("{\}");
| -^ expected `}` in format string
Expand All @@ -61,7 +69,7 @@ LL | let _ = format!("{\}");
= note: if you intended to print `{`, you can escape it using `{{`

error: invalid format string: expected `'}'` but string was terminated
--> $DIR/format-string-error.rs:19:35
--> $DIR/format-string-error.rs:21:35
|
LL | let _ = format!("\n\n\n{\n\n\n");
| - ^ expected `'}'` in format string
Expand All @@ -71,7 +79,7 @@ LL | let _ = format!("\n\n\n{\n\n\n");
= note: if you intended to print `{`, you can escape it using `{{`

error: invalid format string: expected `'}'` but string was terminated
--> $DIR/format-string-error.rs:25:3
--> $DIR/format-string-error.rs:27:3
|
LL | {"###);
| -^ expected `'}'` in format string
Expand All @@ -81,7 +89,7 @@ LL | {"###);
= note: if you intended to print `{`, you can escape it using `{{`

error: invalid format string: expected `'}'` but string was terminated
--> $DIR/format-string-error.rs:33:1
--> $DIR/format-string-error.rs:35:1
|
LL | {
| - because of this opening brace
Expand All @@ -92,26 +100,26 @@ LL | "###);
= note: if you intended to print `{`, you can escape it using `{{`

error: invalid format string: unmatched `}` found
--> $DIR/format-string-error.rs:39:2
--> $DIR/format-string-error.rs:41:2
|
LL | }
| ^ unmatched `}` in format string
|
= note: if you intended to print `}`, you can escape it using `}}`

error: invalid format string: unmatched `}` found
--> $DIR/format-string-error.rs:47:9
--> $DIR/format-string-error.rs:49:9
|
LL | }
| ^ unmatched `}` in format string
|
= note: if you intended to print `}`, you can escape it using `}}`

error: 3 positional arguments in format string, but there are 2 arguments
--> $DIR/format-string-error.rs:51:15
--> $DIR/format-string-error.rs:53:15
|
LL | println!("{} {} {}", 1, 2);
| ^^ ^^ ^^ - -

error: aborting due to 13 previous errors
error: aborting due to 14 previous errors

2 changes: 2 additions & 0 deletions src/test/ui/ifmt.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -90,6 +90,7 @@ pub fn main() {
t!(format!("{foo} {bar}", foo=0, bar=1), "0 1");
t!(format!("{foo} {1} {bar} {0}", 0, 1, foo=2, bar=3), "2 1 3 0");
t!(format!("{} {0}", "a"), "a a");
t!(format!("{_foo}", _foo = 6usize), "6");
t!(format!("{foo_bar}", foo_bar=1), "1");
t!(format!("{}", 5 + 5), "10");
t!(format!("{:#4}", C), "☃123");
Expand Down Expand Up @@ -125,6 +126,7 @@ pub fn main() {
t!(format!("{:.*}", 4, "aaaaaaaaaaaaaaaaaa"), "aaaa");
t!(format!("{:.1$}", "aaaaaaaaaaaaaaaaaa", 4), "aaaa");
t!(format!("{:.a$}", "aaaaaaaaaaaaaaaaaa", a=4), "aaaa");
t!(format!("{:._a$}", "aaaaaaaaaaaaaaaaaa", _a=4), "aaaa");
t!(format!("{:1$}", "a", 4), "a ");
t!(format!("{1:0$}", 4, "a"), "a ");
t!(format!("{:a$}", "a", a=4), "a ");
Expand Down