org.eigenbase.rel.rules
Class ReduceDecimalsRule.PassThroughExpander

java.lang.Object
  org.eigenbase.rel.rules.ReduceDecimalsRule.RexExpander
      org.eigenbase.rel.rules.ReduceDecimalsRule.PassThroughExpander

Enclosing class:

ReduceDecimalsRule

private class ReduceDecimalsRule.PassThroughExpander
extends ReduceDecimalsRule.RexExpander

An expander that substitutes decimals with their integer representations. If the output is decimal, the output is reinterpreted from the integer representation into a decimal.

Field Summary

Fields inherited from class org.eigenbase.rel.rules.ReduceDecimalsRule.RexExpander

builder, int8, real8

Constructor Summary

private

ReduceDecimalsRule.PassThroughExpander(RexBuilder builder)

Method Summary

boolean	canExpand(RexCall call) This defaults to the utility method, RexUtil.requiresDecimalExpansion(RexNode, boolean) which checks general guidelines on whether a rewrite should be considered at all.
RexNode	expand(RexCall call) Rewrites an expression containing decimals.

Methods inherited from class org.eigenbase.rel.rules.ReduceDecimalsRule.RexExpander

accessValue, decodeValue, encodeValue, encodeValue, ensureScale, ensureType, ensureType, makeApproxLiteral, makeApproxScaleFactor, makeCase, makeCase, makeDivide, makeExactLiteral, makeIsNegative, makeIsPositive, makeMinus, makeMultiply, makePlus, makeRoundFactor, makeScaleFactor, matchNullability, powerOfTen, scaleDown, scaleDownDouble, scaleUp

Methods inherited from class java.lang.Object

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

Constructor Detail

ReduceDecimalsRule.PassThroughExpander

private ReduceDecimalsRule.PassThroughExpander(RexBuilder builder)

Method Detail

canExpand

public boolean canExpand(RexCall call)

Description copied from class: ReduceDecimalsRule.RexExpander

This defaults to the utility method, RexUtil.requiresDecimalExpansion(RexNode, boolean) which checks general guidelines on whether a rewrite should be considered at all. In general, it is helpful to update the utility method since that method is often used to filter the somewhat expensive rewrite process.

However, this method provides another place for implementations of RexExpander to make a more detailed analysis before deciding on whether to perform a rewrite.

Overrides:

canExpand in class ReduceDecimalsRule.RexExpander

expand

public RexNode expand(RexCall call)

Description copied from class: ReduceDecimalsRule.RexExpander

Rewrites an expression containing decimals. Normally, this method always performs a rewrite, but implementations may choose to return the original expression if no change was required.

Specified by:

expand in class ReduceDecimalsRule.RexExpander