Function get_numeric_value

src/functions/math_functions.rs:6–51

Helper function to get a numeric value from context, handling both numeric and text inputs

(ctx: &Context<'_>, idx: usize)

/// Helper function to get a numeric value from context, handling both numeric and text inputs
fn get_numeric_value(ctx: &Context<'_>, idx: usize) -> Result<f64> {
    match ctx.get_raw(idx) {
        rusqlite::types::ValueRef::Real(f) => Ok(f),
        rusqlite::types::ValueRef::Integer(i) => Ok(i as f64),
        rusqlite::types::ValueRef::Text(s) => {
            let text = std::str::from_utf8(s).map_err(|e| rusqlite::Error::UserFunctionError(Box::new(e)))?;
            text.trim().parse::<f64>()
                .map_err(|e| rusqlite::Error::UserFunctionError(format!("Failed to parse '{text}' as number: {e}").into()))
        }
        rusqlite::types::ValueRef::Null => {
            // For NULL input, we should propagate it (most SQL functions return NULL for NULL input)
            Err(rusqlite::Error::UserFunctionError("NULL input".into()))
        }
        rusqlite::types::ValueRef::Blob(b) => {
            // Decimal values are stored as 16-byte blobs
            if b.len() == 16 {
                let mut array = [0u8; 16];
                array.copy_from_slice(b);
                let decimal = Decimal::deserialize(array);
                // Convert to f64 - note this may lose precision for very large decimals
                use std::str::FromStr;
                let decimal_str = decimal.to_string();
                f64::from_str(&decimal_str)
                    .map_err(|e| rusqlite::Error::UserFunctionError(
                        format!("Failed to convert decimal to f64: {e}").into()
                    ))
            } else {
                // Try to parse blob as UTF-8 text as fallback
                match std::str::from_utf8(b) {
                    Ok(text) => {
                        text.trim().parse::<f64>()
                            .map_err(|e| rusqlite::Error::UserFunctionError(
                                format!("Failed to parse blob as number: {e}").into()
                            ))
                    }
                    Err(_) => {
                        let len = b.len();
                        Err(rusqlite::Error::UserFunctionError(
                            format!("Invalid blob size for numeric function: {len} bytes").into()
                        ))
                    }
                }
            }
        }
    }
}

/// Register all PostgreSQL math functions
pub fn register_math_functions(conn: &Connection) -> Result<()> {