pub fn json_escape(input: &str) -> String {
let mut out = String::new();
for ch in input.chars() {
match ch {
'\\' => out.push_str("\\\\"),
'"' => out.push_str("\\\""),
'\n' => out.push_str("\\n"),
'\r' => out.push_str("\\r"),
'\t' => out.push_str("\\t"),
c if c.is_control() => out.push_str(&format!("\\u{:04x}", c as u32)),
c => out.push(c),
}
}
out
}