org.apache.calcite.rex

Class RexCall

java.lang.Object

org.apache.calcite.rex.RexNode

org.apache.calcite.rex.RexCall

Direct Known Subclasses:

RexOver, 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
com.google.common.collect.ImmutableList<RexNode>	operands

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

digest

Constructor Summary

Constructors

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

Method Summary

Methods

Modifier and Type	Method and Description
<R> R	accept(RexVisitor<R> visitor) Accepts a visitor, dispatching to the right overloaded visitXxx method.
RexCall	clone(RelDataType type, List<RexNode> operands) Creates a new call to the same operator with different operands.
protected String	computeDigest(boolean withType)
SqlKind	getKind() Returns the kind of node this is.
List<RexNode>	getOperands()
SqlOperator	getOperator()
RelDataType	getType()
boolean	isAlwaysFalse() Returns whether this expression always returns false.
boolean	isAlwaysTrue() Returns whether this expression always returns true.
String	toString()

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

isA, isA

Methods inherited from class java.lang.Object

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

Field Detail

operands

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

Constructor Detail

RexCall

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

Method Detail

computeDigest

protected String computeDigest(boolean withType)

toString

public 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

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()

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