Function cum_reduce_exprs

pub fn cum_reduce_exprs<F, E>(f: F, exprs: E) -> Expr
where
    F: 'static + Fn(Column, Column) -> Result<Option<Column>, PolarsError> + Send + Sync,
    E: AsRef<[Expr]>,

Available on crate features lazy and dtype-struct only.

Accumulate over multiple columns horizontally / row wise.