Function row_number 

pub fn row_number(column: &Column) -> Column

Row number window function (1, 2, 3 by order within partition). Use with .over(partition_by) after ranking by an order column.

Example

use robin_sparkless_expr::{col, Column};
let salary_col = col("salary");
let rn = salary_col.row_number(true).over(&["dept"]);