Struct Functions 

pub struct Functions { /* private fields */ }

The SPQL functions of one scandal, embedded or remote, and their evaluation.

Scan expressions run inside scans. These calls run the same implementations on the caller’s batches, for eager calls and application-engine UDFs.

Implementations

impl Functions

pub async fn new(scandal: Arc<dyn Scandal>) -> Result<Self, Error>

Read the catalog of scandal once; later calls evaluate with it.

pub fn list(&self) -> &[FunctionInfo]

The functions this scandal runs, in identifier order.

pub async fn bind( &self, outputs: &[NamedExpression], input: &Schema, ) -> Result<SchemaRef, Error>

Bind named expressions to an input schema and return the output schema without data.

Scandal resolves each call’s overload and output type exactly as evaluation would.

pub async fn project_stream( &self, outputs: &[NamedExpression], input: BatchStream, ) -> Result<BatchStream, Error>

Evaluate named expressions over a stream of the caller’s batches, row for row.

Binding fails before any input is read. One input batch can yield several output batches, in order. Dropping the output stops reading the input.

pub async fn project_stream_with_scans( &self, outputs: &[NamedExpression], input: BatchStream, scans: &[Scan], ) -> Result<BatchStream, Error>

Project a stream like Self::project_stream, reading blob payloads with the storage of the Tables that scans read.

A payload under a scan’s authorized Table root is read with a fresh binding for that Table, and other references fail.

pub async fn evaluate( &self, outputs: &[NamedExpression], batch: RecordBatch, ) -> Result<Vec<RecordBatch>, Error>

Evaluate named expressions over one of the caller’s batches. The output batches, in order, hold one row per input row.

Trait Implementations

impl Clone for Functions

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.