/*
* Copyright (C) 2020 The Project Lombok Authors.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
package lombok.experimental;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import lombok.AccessLevel;
Put on any field to make lombok build a 'withBy' - a withFieldNameBy method which produces a clone of this object (except for 1 field which gets a new value).
Complete documentation is found at the project lombok features page for @WithBy.
Example:
private @WithBy final int foo;
private @WithBy final String bar;
will generate:
public SELF_TYPE withFooBy(@lombok.NonNull IntUnaryOperator operator) {
int foo = operator.apply(this.foo);
return this.foo == foo ? this : new SELF_TYPE(foo, bar);
}
public SELF_TYPE withBarBy(@lombok.NonNull Function<? super String, ? extends String> operator) {
String bar = operator.apply(this.bar);
return this.bar == bar ? this : new SELF_TYPE(foo, bar);
}
This annotation can also be applied to a class, in which case it'll be as if all non-static fields that don't already have a WithBy annotation have the annotation.
This annotation is primarily useful for hierarchical immutable data structures. For example:
class Movie {
@WithBy private final Director director;
}
class Director {
@WithBy private final LocalDate birthDate;
}
Using plain old @With, to increment a movie's director's birth date by one, you would write: movie = movie.withDirector(movie.getDirector().withBirthDate(movie.getDirector().getBirthDate().plusDays(1)));
but with @WithBy, you'd write: movie = movie.withDirectorBy(d -> d.withBirthDateBy(bd -> bd.plusDays(1)));
/**
* Put on any field to make lombok build a 'withBy' - a withFieldNameBy method which produces a clone of this object (except for 1 field which gets a new value).
* <p>
* Complete documentation is found at <a href="https://projectlombok.org/features/experimental/WithBy">the project lombok features page for @WithBy</a>.
* <p>
* Example:
* <pre>
* private @WithBy final int foo;
* private @WithBy final String bar;
* </pre>
*
* will generate:
*
* <pre>
* public SELF_TYPE withFooBy(@lombok.NonNull IntUnaryOperator operator) {
* int foo = operator.apply(this.foo);
* return this.foo == foo ? this : new SELF_TYPE(foo, bar);
* }
* public SELF_TYPE withBarBy(@lombok.NonNull Function<? super String, ? extends String> operator) {
* String bar = operator.apply(this.bar);
* return this.bar == bar ? this : new SELF_TYPE(foo, bar);
* }
* </pre>
* <p>
* This annotation can also be applied to a class, in which case it'll be as if all non-static fields that don't already have
* a {@code WithBy} annotation have the annotation.
* <p>
* This annotation is primarily useful for hierarchical immutable data structures. For example:
*
* <pre>
* class Movie {
* @WithBy private final Director director;
* }
*
* class Director {
* @WithBy private final LocalDate birthDate;
* }
* </pre>
*
* Using plain old {@code @With}, to increment a movie's director's birth date by one, you would write:
*
* <pre>
* movie = movie.withDirector(movie.getDirector().withBirthDate(movie.getDirector().getBirthDate().plusDays(1)));
* </pre>
*
* but with {@code @WithBy}, you'd write:
*
* <pre>
* movie = movie.withDirectorBy(d -> d.withBirthDateBy(bd -> bd.plusDays(1)));
* </pre>
*/
@Target({ElementType.FIELD, ElementType.TYPE})
@Retention(RetentionPolicy.SOURCE)
public @interface WithBy {
If you want your with method to be non-public, you can specify an alternate access level here.
Returns: The method will be generated with this access modifier.
/**
* If you want your with method to be non-public, you can specify an alternate access level here.
*
* @return The method will be generated with this access modifier.
*/
AccessLevel value() default AccessLevel.PUBLIC;
Any annotations listed here are put on the generated method.
The syntax for this feature depends on JDK version (nothing we can do about that; it's to work around javac bugs).
up to JDK7:
@With(onMethod=@__({@AnnotationsGoHere}))
from JDK8:
@With(onMethod_={@AnnotationsGohere}) // note the underscore after onMethod. Returns: List of annotations to apply to the generated method.
/**
* Any annotations listed here are put on the generated method.
* The syntax for this feature depends on JDK version (nothing we can do about that; it's to work around javac bugs).<br>
* up to JDK7:<br>
* {@code @With(onMethod=@__({@AnnotationsGoHere}))}<br>
* from JDK8:<br>
* {@code @With(onMethod_={@AnnotationsGohere})} // note the underscore after {@code onMethod}.
*
* @return List of annotations to apply to the generated method.
*/
AnyAnnotation[] onMethod() default {};
Placeholder annotation to enable the placement of annotations on the generated code.
Deprecated: Don't use this annotation, ever - Read the documentation.
/**
* Placeholder annotation to enable the placement of annotations on the generated code.
* @deprecated Don't use this annotation, ever - Read the documentation.
*/
@Deprecated
@Retention(RetentionPolicy.SOURCE)
@Target({})
@interface AnyAnnotation {}
}