Struct DynProjection 

pub struct DynProjection(/* private fields */);

Column projection descriptor used to derive projected dynamic views.

Implementations

impl DynProjection

pub fn from_indices<I>( schema: &Schema, indices: I, ) -> Result<Self, DynViewError>

where I: IntoIterator<Item = usize>,

Create a projection from explicit column indices.

Errors

Returns DynViewError::ColumnOutOfBounds if any index exceeds the schema width.

pub fn from_schema( source: &Schema, projection: &Schema, ) -> Result<Self, DynViewError>

Create a projection by matching a projected schema against the source schema.

Fields are matched by name; data type and nullability must also align.

Errors

Returns DynViewError when a projected field is missing from the source schema or when its metadata disagrees.

pub fn fields(&self) -> &Fields

Projected schema fields in order.

pub fn len(&self) -> usize

Number of projected columns.

pub fn is_empty(&self) -> bool

Returns true when the projection contains zero columns.

pub fn to_parquet_mask(&self) -> ParquetProjectionMask

Returns the Parquet projection mask corresponding to this projection.

pub fn project_row_view<'a>( &self, schema: &'a DynSchema, batch: &'a RecordBatch, row: usize, ) -> Result<DynRowView<'a>, DynViewError>

Project a single row from batch using this projection, returning a borrowed view.

Errors

Returns DynViewError when schema validation fails, the row index is out of bounds, or the projection width mismatches the batch.

pub fn project_row_raw( &self, schema: &DynSchema, batch: &RecordBatch, row: usize, ) -> Result<DynRowRaw, DynViewError>

Project a single row from batch and capture it as lifetime-erased raw cells.

Trait Implementations

impl Clone for DynProjection

fn clone(&self) -> DynProjection

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DynProjection

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

Formats the value using the given formatter.