org.apache.gravitino.rel.expressions

Interface Expression

All Known Subinterfaces:

Distribution, FunctionArg, FunctionExpression, Literal<T>, Literal<T>, NamedReference, Partitioning, SortOrder, Transform, UnparsedExpression

All Known Implementing Classes:

BucketPartitioningDTO, DayPartitioningDTO, DistributionDTO, Distributions.DistributionImpl, FieldReferenceDTO, FuncExpressionDTO, FunctionExpression.FuncExpressionImpl, FunctionPartitioningDTO, HourPartitioningDTO, IdentityPartitioningDTO, ListPartitioningDTO, Literal.LiteralImpl, LiteralDTO, Literals.LiteralImpl, MonthPartitioningDTO, NamedReference.FieldReference, Partitioning.SingleFieldPartitioning, RangePartitioningDTO, SortOrderDTO, SortOrders.SortImpl, Transform.SingleFieldTransform, Transforms.ApplyTransform, Transforms.BucketTransform, Transforms.DayTransform, Transforms.HourTransform, Transforms.IdentityTransform, Transforms.ListTransform, Transforms.MonthTransform, Transforms.RangeTransform, Transforms.TruncateTransform, Transforms.YearTransform, TruncatePartitioningDTO, UnparsedExpression.UnparsedExpressionImpl, UnparsedExpressionDTO, YearPartitioningDTO

@Evolving
public interface Expression

Base class of the public logical expression API.

Field Summary

Fields

Modifier and Type	Field and Description
static Expression[]	EMPTY_EXPRESSION `EMPTY_EXPRESSION` is only used as an input when the default `children` method builds the result.
static NamedReference[]	EMPTY_NAMED_REFERENCE `EMPTY_NAMED_REFERENCE` is only used as an input when the default `references` method builds the result array to avoid repeatedly allocating an empty array.

Method Summary

Modifier and Type	Method and Description
Expression[]	children()
default NamedReference[]	references()

Field Detail

EMPTY_EXPRESSION

static final Expression[] EMPTY_EXPRESSION

`EMPTY_EXPRESSION` is only used as an input when the default `children` method builds the result.

EMPTY_NAMED_REFERENCE

static final NamedReference[] EMPTY_NAMED_REFERENCE

`EMPTY_NAMED_REFERENCE` is only used as an input when the default `references` method builds the result array to avoid repeatedly allocating an empty array.

Method Detail

children

Expression[] children()

Returns:

An array of the children of this node. Children should not change.

references

default NamedReference[] references()

Returns:

A list of fields or columns that are referenced by this expression.