Package org.elasticsearch.xpack.esql.core.expression

Class NamedExpression

java.lang.Object

org.elasticsearch.xpack.esql.core.tree.Node<Expression>

org.elasticsearch.xpack.esql.core.expression.Expression

org.elasticsearch.xpack.esql.core.expression.NamedExpression

All Implemented Interfaces:

NamedWriteable, Writeable, Resolvable

Direct Known Subclasses:

Alias, Attribute, UnresolvedNamedExpression

public abstract class NamedExpression
extends Expression
implements NamedWriteable

An expression that has a name. Named expressions can be used as a result (by converting to an attribute).

Nested Class Summary

Nested classes/interfaces inherited from class org.elasticsearch.xpack.esql.core.expression.Expression

Expression.TypeResolution

Nested classes/interfaces inherited from interface org.elasticsearch.common.io.stream.Writeable

Writeable.Reader<V>, Writeable.Writer<V>

Field Summary

Fields inherited from class org.elasticsearch.xpack.esql.core.tree.Node

TO_STRING_MAX_WIDTH

Constructor Summary

Constructors

Constructor	Description
NamedExpression(Source source, String name, List<Expression> children, NameId id)
NamedExpression(Source source, String name, List<Expression> children, NameId id, boolean synthetic)	Assigns a new id if null is passed for id.

Method Summary

Modifier and Type	Method	Description
final boolean	equals(Object o)
final boolean	equals(Object o, boolean ignoreIds)	Polymorphic equality is a pain and can be slow.
final int	hashCode()
final int	hashCode(boolean ignoreIds)
NameId	id()
protected boolean	innerEquals(Object o, boolean ignoreIds)	The actual equality check, after shortcutting this == o and class checks.
protected int	innerHashCode(boolean ignoreIds)
String	name()
String	nodeString()
boolean	synthetic()	Synthetic named expressions are not user defined and usually created during optimizations and substitutions, e.g.
abstract Attribute	toAttribute()	Try to return either this if it is an Attribute, or a ReferenceAttribute to it otherwise.
String	toString()

Methods inherited from class org.elasticsearch.xpack.esql.core.expression.Expression

canonical, canonicalize, childrenResolved, dataType, fold, foldable, nullable, propertiesToString, references, resolved, resolveType, semanticEquals, semanticHash, typeResolved

Methods inherited from class org.elasticsearch.xpack.esql.core.tree.Node

anyMatch, children, collect, collectFirstChildren, collectLeaves, doCollectFirst, forEachDown, forEachDown, forEachDownMayReturnEarly, forEachProperty, forEachPropertyDown, forEachPropertyOnly, forEachPropertyUp, forEachUp, forEachUp, info, nodeName, nodeProperties, replaceChildren, replaceChildrenSameSize, source, sourceLocation, sourceText, transformChildren, transformDown, transformDown, transformDown, transformNodeProps, transformPropertiesDown, transformPropertiesOnly, transformPropertiesUp, transformUp, transformUp, transformUp

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.elasticsearch.common.io.stream.NamedWriteable

getWriteableName

Methods inherited from interface org.elasticsearch.common.io.stream.Writeable

writeTo

Constructor Details

NamedExpression

public NamedExpression(Source source,
 String name,
 List<Expression> children,
 @Nullable
 NameId id)

NamedExpression

public NamedExpression(Source source,
 String name,
 List<Expression> children,
 @Nullable
 NameId id,
 boolean synthetic)

Assigns a new id if null is passed for id.

Method Details

name

public String name()

id

public NameId id()

synthetic

public boolean synthetic()

Synthetic named expressions are not user defined and usually created during optimizations and substitutions, e.g. when turning ... | STATS x = avg(2*field) into ... | EVAL $$synth$attribute = 2*field | STATS x = avg($$synth$attribute).

toAttribute

public abstract Attribute toAttribute()

Try to return either this if it is an Attribute, or a ReferenceAttribute to it otherwise. Return an UnresolvedAttribute if this is unresolved.

hashCode

public final int hashCode()

Overrides:

hashCode in class Node<Expression>

hashCode

public final int hashCode(boolean ignoreIds)

innerHashCode

protected int innerHashCode(boolean ignoreIds)

equals

public final boolean equals(Object o)

Overrides:

equals in class Node<Expression>

equals

public final boolean equals(Object o,
 boolean ignoreIds)

Polymorphic equality is a pain and can be slow. This shortcuts this == o and class checks (important when we expect only a few non-equal objects).

For the actual equality check override innerEquals(Object, boolean) instead.

We also provide the option to ignore NameIds in the equality check, which helps e.g. when creating named expressions while avoiding duplicates, or when attaching failures to unresolved attributes (see Failure.equals). Some classes will always ignore ids, irrespective of the parameter passed here.

innerEquals

protected boolean innerEquals(Object o,
 boolean ignoreIds)

The actual equality check, after shortcutting this == o and class checks.

toString

public String toString()

Overrides:

toString in class Expression

nodeString

public String nodeString()

Overrides:

nodeString in class Node<Expression>