com.edorasware.commons.core.query

Class MergeCompositesPredicateTransformation

java.lang.Object

com.edorasware.commons.core.query.MergeCompositesPredicateTransformation

All Implemented Interfaces:

PredicateTransformation

public final class MergeCompositesPredicateTransformation
extends Object
implements PredicateTransformation

Merges predicates with minimized levels of nesting (resulting in SQL with a minimal number of parentheses). Essentially, the number of created composite predicates is minimized by smartly merging nested predicates wherever operator precedence allows.

See Also:

CompositePredicate

Constructor Summary

Constructors

Constructor and Description
MergeCompositesPredicateTransformation()

Method Summary

Modifier and Type	Method and Description
Predicate	transform(Predicate input) Optionally transform the given predicate.

Methods inherited from class java.lang.Object

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

Constructor Detail

MergeCompositesPredicateTransformation

public MergeCompositesPredicateTransformation()

Method Detail

transform

public Predicate transform(Predicate input)

Description copied from interface: PredicateTransformation

Optionally transform the given predicate. IMPORTANT: this method *must* return the same instance if the predicate was not modified. It is not sufficient to return an equivalent predicate with the same structure. The reason for this is that the code that manages the transformation process needs to check whether further transformations may be required, and doing a 'deep' comparison would not be performant.

Specified by:

transform in interface PredicateTransformation

Parameters:

input - the predicate that may be transformed

Returns:

the transformed predicate, or the input if no transformation was applied