'\'' | '\n' | '\r' | '\t' | '\u{0b}' | '\u{0c}' | '\u{08}' | '\u{07}' | '"' | '\\' => {
c.to_string()
}
+ '\u{0}'..='\u{1f}' => format!("\\x{:x}", c as u32), // print all other control characters in hex.
+ _ => c.to_string(),
+ /*
'\u{a0}'..='\u{d6}' => c.to_string(),
'\u{d8}'..='\u{f6}' => c.to_string(),
'\u{f8}'..='\u{74f}' => c.to_string(),
'\x20'..='\x7e' => c.to_string(),
_ => format!("\\x{:x}\\", c as u32),
+ */
}
}