Revision control
Copy as Markdown
Other Tools
use crate::lossy::{Utf8Lossy, Utf8LossyChunk};
use core::fmt::{Formatter, Result, Write};
pub fn debug_fmt_bytestring(slice: &[u8], f: &mut Formatter<'_>) -> Result {
// Writes out a valid unicode string with the correct escape sequences
fn write_str_escaped(f: &mut Formatter<'_>, s: &str) -> Result {
for c in s.chars().flat_map(|c| c.escape_debug()) {
f.write_char(c)?
}
Ok(())
}
f.write_str("\"")?;
for Utf8LossyChunk { valid, broken } in Utf8Lossy::from_bytes(slice).chunks() {
write_str_escaped(f, valid)?;
for b in broken {
write!(f, "\\x{:02X}", b)?;
}
}
f.write_str("\"")
}
#[cfg(test)]
mod tests {
use super::*;
use crate::fmt::{Debug, Formatter, Result};
use alloc::format;
#[test]
fn smoke() {
struct Helper<'a>(&'a [u8]);
impl Debug for Helper<'_> {
fn fmt(&self, f: &mut Formatter<'_>) -> Result {
debug_fmt_bytestring(self.0, f)
}
}
let input = b"\xF0hello,\tworld";
let expected = r#""\xF0hello,\tworld""#;
let output = format!("{:?}", Helper(input));
assert!(output == expected);
}
}