Skip to content

Preserve single \ in raw string literals #5941

@MichaReiser

Description

@MichaReiser
# Input
pattern_esc = r"'\', '\\'"

# Ruff
pattern_esc = r"'', '\\'"

Expected: Same as input

Probably relevant code:

fn normalize_string(input: &str, quotes: StringQuotes) -> (Cow<str>, ContainsNewlines) {
// The normalized string if `input` is not yet normalized.
// `output` must remain empty if `input` is already normalized.
let mut output = String::new();
// Tracks the last index of `input` that has been written to `output`.
// If `last_index` is `0` at the end, then the input is already normalized and can be returned as is.
let mut last_index = 0;
let mut newlines = ContainsNewlines::No;
let style = quotes.style;
let preferred_quote = style.as_char();
let opposite_quote = style.invert().as_char();
let mut chars = input.char_indices();
while let Some((index, c)) = chars.next() {
if c == '\r' {
output.push_str(&input[last_index..index]);
// Skip over the '\r' character, keep the `\n`
if input.as_bytes().get(index + 1).copied() == Some(b'\n') {
chars.next();
}
// Replace the `\r` with a `\n`
else {
output.push('\n');
}
last_index = index + '\r'.len_utf8();
newlines = ContainsNewlines::Yes;
} else if c == '\n' {
newlines = ContainsNewlines::Yes;
} else if !quotes.triple {
if c == '\\' {
if let Some(next) = input.as_bytes().get(index + 1).copied().map(char::from) {
#[allow(clippy::if_same_then_else)]
if next == opposite_quote {
// Remove the escape by ending before the backslash and starting again with the quote
chars.next();
output.push_str(&input[last_index..index]);
last_index = index + '\\'.len_utf8();
} else if next == preferred_quote {
// Quote is already escaped, skip over it.
chars.next();
} else if next == '\\' {
// Skip over escaped backslashes
chars.next();
}
}
} else if c == preferred_quote {
// Escape the quote
output.push_str(&input[last_index..index]);
output.push('\\');
output.push(c);
last_index = index + preferred_quote.len_utf8();
}
}
}
let normalized = if last_index == 0 {
Cow::Borrowed(input)
} else {
output.push_str(&input[last_index..]);
Cow::Owned(output)
};
(normalized, newlines)
}

Playground

Metadata

Metadata

Assignees

Labels

formatterRelated to the formatter

Type

No type

Projects

No projects

Relationships

None yet

Development

No branches or pull requests

Issue actions