org.eigenbase.rel.rules
Class ReduceDecimalsRule.CaseExpander

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

Enclosing class:

ReduceDecimalsRule

private class ReduceDecimalsRule.CaseExpander
extends ReduceDecimalsRule.RexExpander

Expander that rewrites case expressions, in place. Starting from:

(when $cond then $val)+ else $default

this expander casts all values to the return type. If the target type is a decimal, then the values are then decoded. The result of expansion is that the case operator no longer deals with decimals args. (The return value is encoded if necessary.)

Note: a decimal type is returned iff arguments have decimals

Field Summary

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

builder, int8, real8

Constructor Summary

private

ReduceDecimalsRule.CaseExpander(RexBuilder rexBuilder)

Method Summary

RexNode

expand(RexCall call) Rewrites an expression containing decimals.

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

accessValue, canExpand, 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.CaseExpander

private ReduceDecimalsRule.CaseExpander(RexBuilder rexBuilder)

Method Detail

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