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

Class Literal

java.lang.Object

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

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

org.elasticsearch.xpack.esql.core.expression.LeafExpression

org.elasticsearch.xpack.esql.core.expression.Literal

All Implemented Interfaces:

org.apache.lucene.util.Accountable, NamedWriteable, Writeable, Resolvable, EvaluatorMapper

public class Literal
extends LeafExpression
implements org.apache.lucene.util.Accountable, EvaluatorMapper

Literal or constant.

Nested Class Summary

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

Expression.TypeResolution

Nested classes/interfaces inherited from class org.elasticsearch.xpack.esql.core.tree.Node

Node.NodeStringFormat

Nested classes/interfaces inherited from interface org.elasticsearch.xpack.esql.evaluator.mapper.EvaluatorMapper

EvaluatorMapper.ToEvaluator

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

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

Field Summary

Fields

Modifier and Type	Field	Description
static final NamedWriteableRegistry.Entry	ENTRY
static final Literal	FALSE
static final Literal	NULL
static final Literal	TRUE

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

TO_STRING_MAX_LINES, TO_STRING_MAX_WIDTH

Fields inherited from interface org.apache.lucene.util.Accountable

NULL_ACCOUNTABLE

Constructor Summary

Constructors

Constructor	Description
Literal(Source source, Object value, DataType dataType)

Method Summary

Modifier and Type	Method	Description
DataType	dataType()	The DataType returned by executing the tree rooted at this expression.
static Literal	dateTime(Source source, Instant literal)
boolean	equals(Object obj)
Object	fold(FoldContext ctx)	Evaluate this expression statically to a constant.
boolean	foldable()	Whether the expression can be evaluated statically, aka "folded", or not.
static Expression	fromBoolean(Source source, Boolean literal)
static Literal	fromDouble(Source source, Double literal)
static Literal	fromLong(Source source, Long literal)
String	getWriteableName()
int	hashCode()
protected NodeInfo<? extends Literal>	info()	Normally, you want to use one of the static create methods to implement this.
static Literal	integer(Source source, Integer literal)
static Literal	keyword(Source source, String literal)
void	nodeString(StringBuilder sb, Node.NodeStringFormat format)	Append this Node's string representation to sb.
Nullability	nullable()
static Literal	of(Expression source, Object value)
static Literal	of(FoldContext ctx, Expression foldable)	Utility method for creating a literal out of a foldable expression.
long	ramBytesUsed()
boolean	resolved()
static Literal	text(Source source, String literal)
static Literal	timeDuration(Source source, Duration literal)
ExpressionEvaluator.Factory	toEvaluator(EvaluatorMapper.ToEvaluator toEvaluator)	Convert this into an ExpressionEvaluator.
String	toString()
String	toString(Node.NodeStringFormat format)
Object	value()
void	writeTo(StreamOutput out)

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

canonicalize, references, replaceChildren

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

canonical, childrenResolved, propertiesToString, resolveType, semanticEquals, semanticHash, typeResolved

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

allMatch, anyMatch, children, collect, collect, collect, collectFirstChildren, collectLeaves, doCollectFirst, forEachDown, forEachDown, forEachDownMayReturnEarly, forEachProperty, forEachPropertyDown, forEachPropertyOnly, forEachPropertyUp, forEachUp, forEachUp, nodeName, nodeProperties, nodeString, replaceChildrenSameSize, source, sourceLocation, sourceText, transformChildren, transformChildren, transformDown, transformDown, transformDown, transformDown, transformDownSkipBranch, 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.apache.lucene.util.Accountable

getChildResources

Methods inherited from interface org.elasticsearch.xpack.esql.evaluator.mapper.EvaluatorMapper

fold

Field Details

ENTRY

public static final NamedWriteableRegistry.Entry ENTRY

TRUE

public static final Literal TRUE

FALSE

public static final Literal FALSE

NULL

public static final Literal NULL

Constructor Details

Literal

public Literal(Source source,
 Object value,
 DataType dataType)

Method Details

writeTo

public void writeTo(StreamOutput out)
             throws IOException

Specified by:

writeTo in interface Writeable

Throws:

IOException

getWriteableName

public String getWriteableName()

Specified by:

getWriteableName in interface NamedWriteable

info

protected NodeInfo<? extends Literal> info()

Description copied from class: Node

Normally, you want to use one of the static create methods to implement this.

For QueryPlans, it is very important that the properties contain all of the expressions and references relevant to this node, and that all the properties are used in the provided constructor; otherwise query plan transformations like QueryPlan#transformExpressionsOnly(Function) will not have an effect.

Specified by:

info in class Node<Expression>

value

public Object value()

foldable

public boolean foldable()

Description copied from class: Expression

Whether the expression can be evaluated statically, aka "folded", or not.

Overrides:

foldable in class Expression

nullable

public Nullability nullable()

Specified by:

nullable in class Expression

dataType

public DataType dataType()

Description copied from class: Expression

The DataType returned by executing the tree rooted at this expression. If Expression.typeResolved() returns an error then the behavior of this method is undefined. It may return a valid type. Or it may throw an exception. Or it may return a totally nonsensical type.

Specified by:

dataType in class Expression

resolved

public boolean resolved()

Specified by:

resolved in interface Resolvable

Overrides:

resolved in class Expression

fold

public Object fold(FoldContext ctx)

Description copied from class: Expression

Evaluate this expression statically to a constant. It is an error to call this if Expression.foldable() returns false.

Overrides:

fold in class Expression

hashCode

public int hashCode()

Overrides:

hashCode in class Node<Expression>

equals

public boolean equals(Object obj)

Overrides:

equals in class Node<Expression>

toString

public String toString()

Overrides:

toString in class Expression

toString

public String toString(Node.NodeStringFormat format)

Overrides:

toString in class Expression

nodeString

public void nodeString(StringBuilder sb,
 Node.NodeStringFormat format)

Description copied from class: Node

Append this Node's string representation to sb. This does not include this node's Node.children().

Overrides:

nodeString in class Node<Expression>

Parameters:

sb - target for the string

format - configuration for rendering the string representation

ramBytesUsed

public long ramBytesUsed()

Specified by:

ramBytesUsed in interface org.apache.lucene.util.Accountable

toEvaluator

public ExpressionEvaluator.Factory toEvaluator(EvaluatorMapper.ToEvaluator toEvaluator)

Description copied from interface: EvaluatorMapper

Convert this into an ExpressionEvaluator.

Note for implementors: If you are implementing this function, you should call the passed-in lambda on your children, after doing any other manipulation (casting, etc.) necessary.

Note for Callers: If you are attempting to call this method, and you have an Expression and a Layout, you likely want to call EvalMapper.toEvaluator(org.elasticsearch.xpack.esql.core.expression.FoldContext, org.elasticsearch.xpack.esql.core.expression.Expression, org.elasticsearch.xpack.esql.planner.Layout) instead. On the other hand, if you already have something that looks like the parameter for this method, you should call this method with that function.

Build an ExpressionEvaluator.Factory for the tree of expressions rooted at this node. This is only guaranteed to return a sensible evaluator if this node has a valid type. If this node is a subclass of Expression then "valid type" means that Expression.typeResolved() returns a non-error resolution. If Expression.typeResolved() returns an error then this method may throw. Or return an evaluator that produces garbage. Or return an evaluator that throws when run.

Specified by:

toEvaluator in interface EvaluatorMapper

of

public static Literal of(FoldContext ctx,
 Expression foldable)

Utility method for creating a literal out of a foldable expression. Throws an exception if the expression is not foldable.

of

public static Literal of(Expression source,
 Object value)

keyword

public static Literal keyword(Source source,
 String literal)

text

public static Literal text(Source source,
 String literal)

timeDuration

public static Literal timeDuration(Source source,
 Duration literal)

dateTime

public static Literal dateTime(Source source,
 Instant literal)

integer

public static Literal integer(Source source,
 Integer literal)

fromDouble

public static Literal fromDouble(Source source,
 Double literal)

fromLong

public static Literal fromLong(Source source,
 Long literal)

fromBoolean

public static Expression fromBoolean(Source source,
 Boolean literal)