Trait ExpressionEvaluator 

pub trait ExpressionEvaluator: AsAny {
    // Required method
    fn evaluate(
        &self,
        batch: &dyn EngineData,
    ) -> DeltaResult<Box<dyn EngineData>>;
}

Trait for implementing an Expression evaluator.

It contains one Expression which can be evaluated on multiple ColumnarBatches. Connectors can implement this trait to optimize the evaluation using the connector specific capabilities.

Required Methods

fn evaluate(&self, batch: &dyn EngineData) -> DeltaResult<Box<dyn EngineData>>

Evaluate the expression on a given EngineData.

Produces one value for each row of the input. The data type of the output is same as the type output of the expression this evaluator is using.

Implementors

impl ExpressionEvaluator for DefaultExpressionEvaluator

Available on crate feature arrow-expression and crate feature default-engine-base and (crate features default-engine-native-tls or default-engine-rustls or arrow-conversion) only.