RealizedAggregateExpression (api API)

public interface RealizedAggregateExpression

An expression that can be evaluated across many inputs to eventually yield a single 'scalar' result

Method Summary

Modifier and Type

Method

Description

static RealizedAggregateExpression

create(Type inputType, Type resultType, Expression from, Supplier<Accumulator> constructor)

Create a RealizedAggregateExpression from the given parameters

Expression

getExpression()

Type

getInputType()

The Type that this expression's accumulators accept via Accumulator.accumulate(Object)

Type

getResultType()

The Type that this expression's accumulators emit via Accumulator.process()

Accumulator

newAccumulator()

Method Details
- create
  
  static RealizedAggregateExpression create(Type inputType, Type resultType, Expression from, Supplier<Accumulator> constructor)
  
  Create a RealizedAggregateExpression from the given parameters
  
  Parameters:
  
  inputType - returned from getInputType()
  
  resultType - returned from getResultType()
  
  from - returned from getExpression()
  
  constructor - used to supply Accumulators for newAccumulator()
- getInputType
  
  Type getInputType()
  
  The Type that this expression's accumulators accept via Accumulator.accumulate(Object)
- getResultType
  
  Type getResultType()
  
  The Type that this expression's accumulators emit via Accumulator.process()
- newAccumulator
  
  Accumulator newAccumulator()
  
  Returns:
  
  an Accumulator that can be used for collecting inputs for later processing. Note that this can be called many times to create many accumulators, and that their results can be combined via Accumulator.combine(Accumulator) to support parallelism
- getExpression
  
  Expression getExpression()
  
  Returns:
  
  the Expression that was used to create this RealizedAggregateExpression