Class RemoveRedundantCaseClauses

java.lang.Object

io.trino.sql.ir.optimizer.rule.RemoveRedundantCaseClauses

All Implemented Interfaces:

IrOptimizerRule

public class RemoveRedundantCaseClauses
extends Object
implements IrOptimizerRule

Remove duplicated and redundant clauses in Case. E.g.,

• Case([When(a, r1), When(b, r2), When(a, r3)], d) -> Switch([When(a, r1), When(b, r2)], d)
• Case([When(a, r1), When(true, r2), When(a, r3)], d) -> Switch([When(a, r1)], r2)
• Case([When(a, r1), When(false, r2), When(a, r3)], d) -> Switch([When(a, r1)], d)
• Case([When(true, r)], d) -> r
• Case([When(false, r)], d) -> d

Constructor Summary

Constructors

Constructor	Description
RemoveRedundantCaseClauses()

Method Summary

Modifier and Type	Method	Description
Optional<Expression>	apply(Expression expression, Session session, Map<Symbol,Expression> bindings)

Methods inherited from class java.lang.Object

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

Constructor Details

RemoveRedundantCaseClauses

public RemoveRedundantCaseClauses()

Method Details

apply

public Optional<Expression> apply(Expression expression,
 Session session,
 Map<Symbol,Expression> bindings)

Specified by:

apply in interface IrOptimizerRule