From a991bebe41bd5037323f682301a5fe77ea89b7b9 Mon Sep 17 00:00:00 2001 From: Reinier Zwitserloot Date: Tue, 27 Aug 2019 00:15:02 +0200 Subject: [issue #2368] [withBy] support for javac --- src/core/lombok/experimental/WithBy.java | 112 +++++++++++++++++++++++++++++++ 1 file changed, 112 insertions(+) create mode 100644 src/core/lombok/experimental/WithBy.java (limited to 'src/core/lombok/experimental') diff --git a/src/core/lombok/experimental/WithBy.java b/src/core/lombok/experimental/WithBy.java new file mode 100644 index 00000000..10155b91 --- /dev/null +++ b/src/core/lombok/experimental/WithBy.java @@ -0,0 +1,112 @@ +/* + * 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 {@code 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 {@code @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 {@code @WithBy}, you'd write: + * + *
+ *     movie = movie.withDirectorBy(d -> d.withBirthDateBy(bd -> bd.plusDays(1)));
+ * 
+ */ +@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. + * + * @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:
+ * {@code @With(onMethod=@__({@AnnotationsGoHere}))}
+ * from JDK8:
+ * {@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. + */ + @Deprecated + @Retention(RetentionPolicy.SOURCE) + @Target({}) + @interface AnyAnnotation {} +} -- cgit