Function bigint_to_i256

datafusion/sql/src/expr/value.rs:344–359

Returns None if the value can't be converted to i256. Modified from

(v: &BigInt)

/// 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>
fn bigint_to_i256(v: &BigInt) -> Option<i256> {
    let v_bytes = v.to_signed_bytes_le();
    match v_bytes.len().cmp(&32) {
        Ordering::Less => {
            let mut bytes = if v.is_negative() {
                [255_u8; 32]
            } else {
                [0; 32]
            };
            bytes[0..v_bytes.len()].copy_from_slice(&v_bytes[..v_bytes.len()]);
            Some(i256::from_le_bytes(bytes))
        }
        Ordering::Equal => Some(i256::from_le_bytes(v_bytes.try_into().unwrap())),
        Ordering::Greater => None,
    }
}

fn parse_decimal(unsigned_number: &str, negative: bool) -> Result<Expr> {
    let mut dec = BigDecimal::from_str(unsigned_number).map_err(|e| {