Package io.substrait.expression

Class LambdaBuilder.Scope

java.lang.Object

io.substrait.expression.LambdaBuilder.Scope

Enclosing class:

LambdaBuilder

public class LambdaBuilder.Scope
extends Object

A handle to a particular lambda's parameter scope. Use ref(int) to create validated parameter references.

Each Scope captures the depth of the lambdaContext stack at the time it was created. When ref(int) is called, the Substrait stepsOut value is computed as the difference between the current stack depth and the captured depth. This means the same Scope produces different stepsOut values depending on the nesting level at the time of the call, which is what allows outer.ref(0) to produce stepsOut=1 when called inside a nested lambda.

Method Summary

Modifier and Type	Method	Description
FieldReference	ref(int paramIndex)	Creates a validated reference to a parameter of this lambda.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

ref

public FieldReference ref(int paramIndex)
                   throws IndexOutOfBoundsException

Creates a validated reference to a parameter of this lambda.

Parameters:

paramIndex - index of the parameter within this lambda's parameter struct

Returns:

a FieldReference pointing to the specified parameter

Throws:

IndexOutOfBoundsException - if paramIndex is out of bounds