Function try_decode_hex_char

datafusion/sql/src/expr/value.rs:333–340

Try to decode a byte from a hex char. None will be returned if the input char is hex-invalid.

(c: u8)

///
/// None will be returned if the input char is hex-invalid.
const fn try_decode_hex_char(c: u8) -> Option<u8> {
    match c {
        b'A'..=b'F' => Some(c - b'A' + 10),
        b'a'..=b'f' => Some(c - b'a' + 10),
        b'0'..=b'9' => Some(c - b'0'),
        _ => None,
    }
}

/// Returns None if the value can't be converted to i256.
/// Modified from <https://github.com/apache/arrow-rs/blob/c4dbf0d8af6ca5a19b8b2ea777da3c276807fc5e/arrow-buffer/src/bigint/mod.rs#L303>