Class CoerceInputsRule

  extended by org.eigenbase.relopt.RelOptRule
      extended by 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.

$Id: //open/dev/farrago/src/org/eigenbase/rel/rules/ $
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


private final Class consumerRelClass


private final boolean coerceNames
Constructor Detail


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

consumerRelClass - the RelNode class which will consume the inputs
coerceNames - if true, coerce names and types; if false, coerce type only
Method Detail


public CallingConvention getOutConvention()
Description copied from class: RelOptRule
Returns the calling convention of the result of firing this rule, null if not known.

getOutConvention in class RelOptRule


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
call - Rule call
See Also: