Function decode_unicode

crates/stdlib/src/json/machinery.rs:258–271

(it: &mut I, pos: usize)

#[inline]
fn decode_unicode<I>(it: &mut I, pos: usize) -> Result<CodePoint, DecodeError>
where
    I: Iterator<Item = (usize, (usize, CodePoint))>,
{
    flame_guard!("machinery::decode_unicode");
    let err = || DecodeError::new("Invalid \\uXXXX escape", pos);
    let mut uni = 0u16;
    for _ in 0..4 {
        let (_, (_, c)) = it.next().ok_or_else(err)?;
        let d = c.to_char().and_then(|c| c.to_digit(16)).ok_or_else(err)? as u16;
        uni = (uni << 4) | d;
    }
    Ok(uni.into())
}