Hello
The `org.apache.maven.api.model` package of Maven 4 contains classes
generated automatically from the `maven.mdo` file [1], which describes
the POM. The generated classes are similar to Java records
(unmodifiable, straightforward getter methods, etc.). However, they have
a lot of boilerplate that could delegated to Java record:
* All the getter methods
* Implementation of equals, hashCode and toString
* Builder and `with` method for each property (could be replaced by
JEP 468 [2] - in preview)
Records also have facilities that we cannot reproduce, such as record
pattern [3]. Should we migrate, or prepare migration, of part of the
Maven API to record?
A first limitation is that a record cannot extend another class or
record. For the `org.apache.maven.api.model` package, we could turn the
base classes `ModelBase`, `BuildBase`, `RepositoryBase`, `Repository`,
`PatternSet` and `FileSet` into interfaces and accept to repeat
properties in records that implement the same interfaces.
Another limitation is that records benefits provided by JEP 440 and 468
are not available in Java 17 (the version required by Maven). We could
keep the generation of the `with` methods for now with a warning saying
that they may be removed in a future version. We would still have the
other benefits and be prepared for this evolution.
Any though?
Martin
[1]https://github.com/apache/maven/blob/master/api/maven-api-model/src/main/mdo/maven.mdo
[2]https://openjdk.org/jeps/468
[3]https://openjdk.org/jeps/440
