org.eigenbase.rel.rules
Class CoerceInputsRule

java.lang.Object
  org.eigenbase.relopt.RelOptRule
      org.eigenbase.rel.rules.CoerceInputsRule

public class CoerceInputsRule
extends RelOptRule

CoerceInputsRule precasts inputs to a particular type. This can be used to assist operator implementations which impose requirements on their input types.

Version:

$Id: //open/dev/farrago/src/org/eigenbase/rel/rules/CoerceInputsRule.java#2 $

Author:

John V. Sichi

Field Summary

private boolean	coerceNames
private Class	consumerRelClass

Fields inherited from class org.eigenbase.relopt.RelOptRule

ANY, description, operands

Constructor Summary

CoerceInputsRule(Class<? extends RelNode> consumerRelClass, boolean coerceNames)
Constructs the rule.

Method Summary

CallingConvention	getOutConvention() Returns the calling convention of the result of firing this rule, null if not known.
void	onMatch(RelOptRuleCall call) Receives notification about a rule match.

Methods inherited from class org.eigenbase.relopt.RelOptRule

convert, equals, equals, getOperand, getOperands, getOutTrait, hashCode, matches, mergeTraitsAndConvert, mergeTraitsAndConvert, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

consumerRelClass

private final Class consumerRelClass

coerceNames

private final boolean coerceNames

Constructor Detail

CoerceInputsRule

public CoerceInputsRule(Class<? extends RelNode> consumerRelClass,
                        boolean coerceNames)

Constructs the rule.

Parameters:

consumerRelClass - the RelNode class which will consume the inputs

coerceNames - if true, coerce names and types; if false, coerce type only

Method Detail

getOutConvention

public CallingConvention getOutConvention()

Description copied from class: RelOptRule

Returns the calling convention of the result of firing this rule, null if not known.

Overrides:

getOutConvention in class RelOptRule

onMatch

public void onMatch(RelOptRuleCall call)

Description copied from class: RelOptRule

Receives notification about a rule match. At the time that this method is called, call.rels holds the set of relational expressions which match the operands to the rule; call.rels[0] is the root expression.

Typically a rule would check that the nodes are valid matches, creates a new expression, then calls back RelOptRuleCall.transformTo(org.eigenbase.rel.RelNode) to register the expression.

Specified by:

onMatch in class RelOptRule

Parameters:

call - Rule call

See Also:

RelOptRule.matches(RelOptRuleCall)