saffron.rel
Class UnionToDistinctRule
java.lang.Object
|
+--saffron.opt.Rule
|
+--saffron.rel.UnionToDistinctRule
- public class UnionToDistinctRule
- extends Rule
UnionToDistinctRule
translates a distinct Union
(all
= false
) into a Distinct
on top
of a non-distinct Union
(all
= true
).
Method Summary |
void |
onMatch(RuleCall call)
This method is called every time the rule matches. |
UnionToDistinctRule
public UnionToDistinctRule()
onMatch
public void onMatch(RuleCall call)
- Description copied from class:
Rule
- This method is called every time the rule matches. 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 RuleCall.transformTo(saffron.rel.Rel)
to
register the expression.
- Specified by:
onMatch
in class Rule