rust/src/librustdoc/html/escape.rs
2019-12-22 17:42:47 -05:00

44 lines
1.4 KiB
Rust

//! HTML escaping.
//!
//! This module contains one unit struct, which can be used to HTML-escape a
//! string of text (for use in a format string).
use std::fmt;
/// Wrapper struct which will emit the HTML-escaped version of the contained
/// string when passed to a format string.
pub struct Escape<'a>(pub &'a str);
impl<'a> fmt::Display for Escape<'a> {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
// Because the internet is always right, turns out there's not that many
// characters to escape: http://stackoverflow.com/questions/7381974
let Escape(s) = *self;
let pile_o_bits = s;
let mut last = 0;
for (i, ch) in s.bytes().enumerate() {
match ch as char {
'<' | '>' | '&' | '\'' | '"' => {
fmt.write_str(&pile_o_bits[last..i])?;
let s = match ch as char {
'>' => "&gt;",
'<' => "&lt;",
'&' => "&amp;",
'\'' => "&#39;",
'"' => "&quot;",
_ => unreachable!(),
};
fmt.write_str(s)?;
last = i + 1;
}
_ => {}
}
}
if last < s.len() {
fmt.write_str(&pile_o_bits[last..])?;
}
Ok(())
}
}