Method execute_for_statement

graphlite/src/exec/executor.rs:7150–7189

Execute FOR statement: FOR [alias:] variable IN expression

(
        &self,
        for_stmt: &crate::ast::ForStatement,
        context: &mut ExecutionContext,
    )

    /// Execute FOR statement: FOR [alias:] variable IN expression
    fn execute_for_statement(
        &self,
        for_stmt: &crate::ast::ForStatement,
        context: &mut ExecutionContext,
    ) -> Result<QueryResult, ExecutionError> {
        // FOR statements iterate over a collection
        // The expression should evaluate to a list or collection

        let mut result = QueryResult::new();

        // Evaluate the expression to get the collection
        let collection_value = self.evaluate_expression(&for_stmt.expression, context)?;

        // Convert the value to a collection
        let collection = match collection_value {
            Value::List(items) => items,
            Value::String(s) => {
                // String can be treated as a collection of characters
                s.chars().map(|c| Value::String(c.to_string())).collect()
            }
            _ => {
                // Single value becomes a collection of one
                vec![collection_value]
            }
        };

        // Set up the result variable name
        let variable_name = for_stmt.alias.as_ref().unwrap_or(&for_stmt.variable);
        result.variables.push(variable_name.clone());

        // Create a row for each item in the collection
        for item in collection {
            let mut row = Row::new();
            row.add_value(variable_name.clone(), item.clone());
            row.positional_values.push(item);
            result.rows.push(row);
        }

        Ok(result)
    }

    /// Execute FILTER statement: FILTER [WHERE] expression
    fn execute_filter_statement(