Struct WindowContext 

pub struct WindowContext { /* private fields */ }

Context for evaluating window functions

Implementations

impl WindowContext

pub fn new( view: Arc<DataView>, partition_by: Vec<String>, order_by: Vec<OrderByColumn>, ) -> Result<Self>

Create a new window context with partitioning and ordering

pub fn get_offset_value( &self, current_row: usize, offset: i32, column: &str, ) -> Option<DataValue>

Get value at offset from current row (for LAG/LEAD)

pub fn get_row_number(&self, row_index: usize) -> usize

Get row number within partition (1-based)

pub fn get_first_value( &self, row_index: usize, column: &str, ) -> Option<DataValue>

Get first value in partition

pub fn get_last_value( &self, row_index: usize, column: &str, ) -> Option<DataValue>

Get last value in partition

pub fn partition_count(&self) -> usize

Get the number of partitions

pub fn has_partitions(&self) -> bool

Check if context has partitions (vs single window)

pub fn get_partition_sum( &self, row_index: usize, column: &str, ) -> Option<DataValue>

Calculate sum of a column over the partition containing the given row

pub fn get_partition_count( &self, row_index: usize, column: Option<&str>, ) -> Option<DataValue>

Calculate count of non-null values in a column over the partition