Method execute

graphlite/src/functions/aggregate_functions.rs:43–70

(&self, context: &FunctionContext)

    }

    fn execute(&self, context: &FunctionContext) -> FunctionResult<Value> {
        // If no arguments, count all rows
        if context.argument_count() == 0 {
            return Ok(Value::Number(context.rows.len() as f64));
        }

        // If argument provided, count non-null values in that column
        let column_name = context.get_argument(0)?.as_string().ok_or_else(|| {
            FunctionError::InvalidArgumentType {
                message: "COUNT argument must be a string column name".to_string(),
            }
        })?;

        // Special case: COUNT(*) should count all rows
        if column_name == "*" {
            return Ok(Value::Number(context.rows.len() as f64));
        }

        let mut count = 0;
        for row in &context.rows {
            if let Some(value) = row.values.get(column_name) {
                if !value.is_null() {
                    count += 1;
                }
            }
        }
        Ok(Value::Number(count as f64))
    }

    fn return_type(&self) -> &str {
        "Number"