Function pow_decimal_float_fallback

datafusion/functions/src/math/power.rs:254–272

Fallback implementation using f64 for negative or non-integer exponents. This handles cases that cannot be computed using integer arithmetic.

(base: T, scale: i8, exp: f64)

/// Fallback implementation using f64 for negative or non-integer exponents.
/// This handles cases that cannot be computed using integer arithmetic.
fn pow_decimal_float_fallback<T>(base: T, scale: i8, exp: f64) -> Result<T, ArrowError>
where
    T: ToPrimitive + NumCast + Copy,
{
    if scale < 0 {
        return Err(ArrowError::NotYetImplemented(format!(
            "Negative scale is not yet supported: {scale}"
        )));
    }

    let scale_factor = 10f64.powi(scale as i32);
    let base_f64 = base.to_f64().ok_or_else(|| {
        ArrowError::ComputeError("Cannot convert base to f64".to_string())
    })? / scale_factor;

    let result_i128 = compute_pow_f64_result(base_f64, scale, exp)?;

    decimal_from_i128(result_i128)
}

/// Decimal256 specialized float exponent version.
fn pow_decimal256_float(base: i256, scale: i8, exp: f64) -> Result<i256, ArrowError> {