net.sf.saffron.rex
Class RexCall

java.lang.Object
  |
  +--net.sf.saffron.rex.RexNode
        |
        +--net.sf.saffron.rex.RexCall

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.)

Since:

Nov 24, 2003

Version:

$Id: $

Author:

jhyde

Field Summary

private RexKind	kind
SqlOperator	op
RexNode[]	operands
private SaffronType	type

Fields inherited from class net.sf.saffron.rex.RexNode

digest

Constructor Summary

(package private)

RexCall(SaffronType type, SqlOperator op, RexNode[] operands)

Method Summary

Object	clone()
private String	computeDigest()
RexKind	getKind() Returns the kind of node this is.
SaffronType	getType()
(package private) static RexKind	sqlKindToRexKind(SqlKind kind) Returns the RexKind corresponding to a SqlKind.

Methods inherited from class net.sf.saffron.rex.RexNode

isA, isAlwaysTrue, toString

Methods inherited from class java.lang.Object

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

Field Detail

op

public final SqlOperator op

operands

public final RexNode[] operands

type

private final SaffronType type

kind

private final RexKind kind

Constructor Detail

RexCall

RexCall(SaffronType type,
        SqlOperator op,
        RexNode[] operands)

Method Detail

sqlKindToRexKind

static RexKind sqlKindToRexKind(SqlKind kind)

Returns the RexKind corresponding to a SqlKind. Fails if there is none.

Post-condition:

return != null

Test-case:

RexTest.testKindMapping()

computeDigest

private String computeDigest()

getType

public SaffronType getType()

Specified by:

getType in class RexNode

clone

public Object clone()

Specified by:

clone in class RexNode

getKind

public RexKind getKind()

Description copied from class: RexNode

Returns the kind of node this is.

Overrides:

getKind in class RexNode

Returns:

A RexKind value, never null