Struct CastExpr

pub struct CastExpr {
    pub expr: Arc<dyn PhysicalExpr>,
    /* private fields */
}

CAST expression casts an expression to a specific data type and returns a runtime error on invalid cast

Fields

expr: Arc<dyn PhysicalExpr>

The expression to cast

Implementations

impl CastExpr

pub fn new( expr: Arc<dyn PhysicalExpr>, cast_type: DataType, cast_options: Option<CastOptions<'static>>, ) -> CastExpr

Create a new CastExpr

pub fn expr(&self) -> &Arc<dyn PhysicalExpr>

The expression to cast

pub fn cast_type(&self) -> &DataType

The data type to cast to

pub fn cast_options(&self) -> &CastOptions<'static>

The cast options

pub fn is_bigger_cast(&self, src: &DataType) -> bool

Check if the cast is a widening cast (e.g. from Int8 to Int16).

Trait Implementations

impl Clone for CastExpr

fn clone(&self) -> CastExpr

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CastExpr

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

Formats the value using the given formatter.

impl Display for CastExpr

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

Formats the value using the given formatter.

impl Hash for CastExpr

fn hash<H>(&self, state: &mut H)

where H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for CastExpr

fn eq(&self, other: &CastExpr) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PhysicalExpr for CastExpr

fn as_any(&self) -> &(dyn Any + 'static)

Return a reference to Any that can be used for downcasting

fn get_properties( &self, children: &[ExprProperties], ) -> Result<ExprProperties, DataFusionError>

A CastExpr preserves the ordering of its child if the cast is done under the same datatype family.

fn data_type(&self, _input_schema: &Schema) -> Result<DataType, DataFusionError>

Get the data type of this expression, given the schema of the input

fn nullable(&self, input_schema: &Schema) -> Result<bool, DataFusionError>

Determine whether this expression is nullable, given the schema of the input

fn evaluate( &self, batch: &RecordBatch, ) -> Result<ColumnarValue, DataFusionError>

Evaluate an expression against a RecordBatch

fn return_field( &self, input_schema: &Schema, ) -> Result<Arc<Field>, DataFusionError>

The output field associated with this expression

fn children(&self) -> Vec<&Arc<dyn PhysicalExpr>>

Get a list of child PhysicalExpr that provide the input for this expr.

fn with_new_children( self: Arc<CastExpr>, children: Vec<Arc<dyn PhysicalExpr>>, ) -> Result<Arc<dyn PhysicalExpr>, DataFusionError>

Returns a new PhysicalExpr where all children were replaced by new exprs.

fn evaluate_bounds( &self, children: &[&Interval], ) -> Result<Interval, DataFusionError>

Computes the output interval for the expression, given the input intervals.

fn propagate_constraints( &self, interval: &Interval, children: &[&Interval], ) -> Result<Option<Vec<Interval>>, DataFusionError>

Updates bounds for child expressions, given a known interval for this expression.

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

Format this PhysicalExpr in nice human readable “SQL” format

fn evaluate_selection( &self, batch: &RecordBatch, selection: &BooleanArray, ) -> Result<ColumnarValue, DataFusionError>

Evaluate an expression against a RecordBatch after first applying a validity array

fn evaluate_statistics( &self, children: &[&Distribution], ) -> Result<Distribution, DataFusionError>

Computes the output statistics for the expression, given the input statistics.

fn propagate_statistics( &self, parent: &Distribution, children: &[&Distribution], ) -> Result<Option<Vec<Distribution>>, DataFusionError>

Updates children statistics using the given parent statistic for this expression.

fn snapshot(&self) -> Result<Option<Arc<dyn PhysicalExpr>>, DataFusionError>

Take a snapshot of this PhysicalExpr, if it is dynamic.

fn snapshot_generation(&self) -> u64

Returns the generation of this PhysicalExpr for snapshotting purposes. The generation is an arbitrary u64 that can be used to track changes in the state of the PhysicalExpr over time without having to do an exhaustive comparison. This is useful to avoid unecessary computation or serialization if there are no changes to the expression. In particular, dynamic expressions that may change over time; this allows cheap checks for changes. Static expressions that do not change over time should return 0, as does the default implementation. You should not call this method directly as it does not handle recursion. Instead use snapshot_generation to handle recursion and capture the full state of the PhysicalExpr.

impl Eq for CastExpr