org.apache.calcite.rex

Class RexCall

java.lang.Object

org.apache.calcite.rex.RexNode

org.apache.calcite.rex.RexCall

Direct Known Subclasses:

Match.RexMRAggCall, RexOver, RexSubQuery, Window.RexWinAggCall

public class RexCall
extends RexNode

An expression formed by a call to an operator with zero or more expressions as operands.

Operators may be binary, unary, functions, special syntactic constructs like CASE ... WHEN ... END, or even internally generated constructs like implicit type conversions. The syntax of the operator is really irrelevant, because row-expressions (unlike SQL expressions) do not directly represent a piece of source code.

It's not often necessary to sub-class this class. The smarts should be in the operator, rather than the call. Any extra information about the call can often be encoded as extra arguments. (These don't need to be hidden, because no one is going to be generating source code from this tree.)

Field Summary

Fields

Modifier and Type	Field and Description
protected int	hash Cache of hash code.
int	nodeCount
SqlOperator	op
com.google.common.collect.ImmutableList<RexNode>	operands
RelDataType	type

Fields inherited from class org.apache.calcite.rex.RexNode

digest

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	RexCall(RelDataType type, SqlOperator operator, List<? extends RexNode> operands)

Method Summary

Modifier and Type	Method and Description
<R,P> R	accept(RexBiVisitor<R,P> visitor, P arg) Accepts a visitor with a payload, dispatching to the right overloaded RexBiVisitor.visitInputRef(RexInputRef, Object) visitXxx} method.
<R> R	accept(RexVisitor<R> visitor) Accepts a visitor, dispatching to the right overloaded visitXxx method.
protected void	appendOperands(StringBuilder sb) Appends call operands without parenthesis.
RexCall	clone(RelDataType type, List<RexNode> operands) Creates a new call to the same operator with different operands.
protected String	computeDigest(boolean withType)
boolean	equals(@Nullable Object o)
SqlKind	getKind() Returns the kind of node this is.
List<RexNode>	getOperands()
SqlOperator	getOperator()
RelDataType	getType()
int	hashCode()
boolean	isAlwaysFalse() Returns whether this expression always returns false.
boolean	isAlwaysTrue() Returns whether this expression always returns true.
int	nodeCount() Returns the number of nodes in this expression.
String	toString()

Methods inherited from class org.apache.calcite.rex.RexNode

isA, isA

Methods inherited from class java.lang.Object

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

Field Detail

op

public final SqlOperator op

operands

public final com.google.common.collect.ImmutableList<RexNode> operands

type

public final RelDataType type

nodeCount

public final int nodeCount

hash

protected int hash

Cache of hash code.

Constructor Detail

RexCall

protected RexCall(RelDataType type,
                  SqlOperator operator,
                  List<? extends RexNode> operands)

Method Detail

appendOperands

protected final void appendOperands(StringBuilder sb)

Appends call operands without parenthesis. RexLiteral might omit data type depending on the context. For instance, null:BOOLEAN vs =(true, null). The idea here is to omit "obvious" types for readability purposes while still maintain RelNode.getDigest() contract.

Parameters:

sb - destination

See Also:

RexLiteral.computeDigest(RexDigestIncludeType)

computeDigest

protected String computeDigest(boolean withType)

toString

public final String toString()

Overrides:

toString in class RexNode

accept

public <R> R accept(RexVisitor<R> visitor)

Description copied from class: RexNode

Accepts a visitor, dispatching to the right overloaded visitXxx method.

Also see RexUtil.apply(RexVisitor, java.util.List, RexNode), which applies a visitor to several expressions simultaneously.

Specified by:

accept in class RexNode

accept

public <R,P> R accept(RexBiVisitor<R,P> visitor,
                      P arg)

Description copied from class: RexNode

Accepts a visitor with a payload, dispatching to the right overloaded RexBiVisitor.visitInputRef(RexInputRef, Object) visitXxx} method.

Specified by:

accept in class RexNode

getType

public RelDataType getType()

Specified by:

getType in class RexNode

isAlwaysTrue

public boolean isAlwaysTrue()

Description copied from class: RexNode

Returns whether this expression always returns true. (Such as if this expression is equal to the literal TRUE.)

Overrides:

isAlwaysTrue in class RexNode

isAlwaysFalse

public boolean isAlwaysFalse()

Description copied from class: RexNode

Returns whether this expression always returns false. (Such as if this expression is equal to the literal FALSE.)

Overrides:

isAlwaysFalse in class RexNode

getKind

public SqlKind getKind()

Description copied from class: RexNode

Returns the kind of node this is.

Overrides:

getKind in class RexNode

Returns:

Node kind, never null

getOperands

public List<RexNode> getOperands()

getOperator

public SqlOperator getOperator()

nodeCount

public int nodeCount()

Description copied from class: RexNode

Returns the number of nodes in this expression.

Leaf nodes, such as RexInputRef or RexLiteral, have a count of 1. Calls have a count of 1 plus the sum of their operands.

Node count is a measure of expression complexity that is used by some planner rules to prevent deeply nested expressions.

Overrides:

nodeCount in class RexNode

clone

public RexCall clone(RelDataType type,
                     List<RexNode> operands)

Creates a new call to the same operator with different operands.

Parameters:

type - Return type

operands - Operands to call

Returns:

New call

equals

public boolean equals(@Nullable Object o)

Description copied from class: RexNode

Every node must implement RexNode.equals(java.lang.Object) based on its content

Specified by:

equals in class RexNode

hashCode

public int hashCode()

Description copied from class: RexNode

Every node must implement RexNode.hashCode() consistent with RexNode.equals(java.lang.Object)

Specified by:

hashCode in class RexNode