Struct RowWindow 

pub struct RowWindow { /* private fields */ }

One window of a RowSource, with its first rows and its count; see the module docs.

Implementations

impl RowWindow

pub fn reader() -> WindowReader

How to read: offset, length, sample and counting.

pub fn read( source: impl RowSource, offset: usize, len: usize, ) -> Result<Self, DataError>

The rows offset..offset + len of source, counting the rest.

pub fn columns(&self) -> &[String]

The column names.

pub fn schema(&self) -> Option<&Schema>

The source’s schema, if it had one.

pub fn start(&self) -> usize

The 0-based index of the window’s first row.

pub fn rows(&self) -> &[Row]

The window’s rows.

pub fn total(&self) -> Option<usize>

How many rows the source had, when it was read to the end.

pub fn to_virtual_table(&self) -> VirtualTable<&RowWindow>

The window as a virtualised table: typed alignment from the schema (or the sampled cells), positioned on the window.

Trait Implementations

impl Clone for RowWindow

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for RowWindow

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl VirtualRows for RowWindow

fn row_count(&self) -> Option<usize>

How many rows there are, when the source knows.

fn row(&self, index: usize) -> Option<Vec<Value>>

The row at index (0-based), or None past the end.

fn rows(&self, start: usize, len: usize) -> Vec<Vec<Value>>

Up to len rows from start, fewer at the end. The default calls row until it returns None.

fn rows_columns( &self, start: usize, len: usize, columns: &[usize], ) -> Vec<Vec<Value>>

Up to len rows from start, each with only the cells of columns (0-based, in that order; a cell past the row’s end is null): what a column window of a wide table fetches. The default calls rows and picks the cells; a source that can read some columns without the rest (a columnar file, a query, cells computed on demand such as FnCells) overrides it.