net.sf.farrago.ojrex
Class FarragoOJRexReinterpretImplementor

java.lang.Object
  net.sf.farrago.ojrex.FarragoOJRexImplementor
      net.sf.farrago.ojrex.FarragoOJRexReinterpretImplementor

All Implemented Interfaces:

OJRexImplementor

public class FarragoOJRexReinterpretImplementor
extends FarragoOJRexImplementor

An OJRexImplementor for reinterpret casts. Reinterpret casts are important for generated Java code, because while Sql types may share the same primitive types, they may require different wrappers. Currently this class can only handle conversions between Decimals and Bigints.

Version:

$Id: //open/dev/farrago/src/net/sf/farrago/ojrex/FarragoOJRexReinterpretImplementor.java#13 $

Author:

John Pham

Constructor Summary

FarragoOJRexReinterpretImplementor()
Constructs an OJRexReinterpretCastImplementor

Method Summary

boolean	canImplement(RexCall call) Tests whether it is possible to implement a call.
private void	checkNullability(FarragoRexToOJTranslator translator, RelDataType targetType, RexNode rexValue, Expression javaValue) Inserts a null test if a value is nullable, but a target type is not.
Expression	implementFarrago(FarragoRexToOJTranslator translator, RexCall call, Expression[] operands) Refined version of OJRexImplementor.implement(org.eigenbase.oj.rex.RexToOJTranslator, org.eigenbase.rex.RexCall, openjava.ptree.Expression[]).

Methods inherited from class net.sf.farrago.ojrex.FarragoOJRexImplementor

implement

Methods inherited from class java.lang.Object

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

Constructor Detail

FarragoOJRexReinterpretImplementor

public FarragoOJRexReinterpretImplementor()

Constructs an OJRexReinterpretCastImplementor

Method Detail

canImplement

public boolean canImplement(RexCall call)

Description copied from interface: OJRexImplementor

Tests whether it is possible to implement a call.

Specified by:

canImplement in interface OJRexImplementor

Overrides:

canImplement in class FarragoOJRexImplementor

Parameters:

call - the call for which translation is being considered

Returns:

whether the call can be implemented

implementFarrago

public Expression implementFarrago(FarragoRexToOJTranslator translator,
                                   RexCall call,
                                   Expression[] operands)

Description copied from class: FarragoOJRexImplementor

Refined version of OJRexImplementor.implement(org.eigenbase.oj.rex.RexToOJTranslator, org.eigenbase.rex.RexCall, openjava.ptree.Expression[]).

Specified by:

implementFarrago in class FarragoOJRexImplementor

Parameters:

translator - provides Farrago-specific translation context

call - the call to be translated

operands - call's operands, which have already been translated independently

checkNullability

private void checkNullability(FarragoRexToOJTranslator translator,
                              RelDataType targetType,
                              RexNode rexValue,
                              Expression javaValue)

Inserts a null test if a value is nullable, but a target type is not.