define the scala 2 macros in the scala 3 module #480
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# Conflicts: # build.sbt
| libraryDependencies ++= Dependencies.scalaLogging(scalaVersion.value, false), | ||
| ) | ||
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| lazy val `integration-test` = project.in(file("integration-test")) |
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It is expected that external dependencies should be used, especially to test CrossVersion.for2_13Use3, Currently only local testing
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@SethTisue I will test CrossVersion.for2_13Use3 and CrossVersion.for3Use2_13 locally and release 4.0.0-RC1, what do you think?
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I don't understand the motivation for testing CrossVersion.for2_13Use3 and CrossVersion.for3Use2_13? if the library is published for both 2 and 3, then 2 users should use the 2 version, 3 users should use the 3 version
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Is it because the macro for 2 is defined in 3? Because it's mentioned in the Scala documentation, to be honest, I'm not sure if it's necessary.
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Is it because the macro for 2 is defined in 3?
There's no such thing — Scala 2 macros and Scala 3 macros are entirely separate systems. There is zero interoperability of macros in either direction.
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Thank you for clarifying. Can I merge it? I have already preserved the 3.x branch.
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I have no objection! starting a new 4.x series seems like an excellent idea to me. sorry for the delayed reply
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2 users should use the 2 version, 3 users should use the 3 version
@SethTisue it's not the case if it's a transitive dependency in a mixed scala2/3 application.
For example you're using scala 2 for your main app, but your code depends on a scala 3 library which in turn depends on scala-logging for scala 3.
The only reason that wouldn't work traditionally is that the scala 3 library wouldn't include the scala 2 macros, but with this PR the scala 2 macros would also be included thus the macros could work on the scala 2 parts of your codebase.
This facility unlocks a lot of flexibility for upgrading large scala 2 projects piece by piece.
(Having said all that, I remember someone once showing me a technique where app developers can have both the scala 2 and 3 library both present as a whole in their app, which would be similarly flexible but simpler for the library maintainers.)
Continue pushing #415 forward. We still need some integration testing. It will close #415 and #350.
This implementation is also the most reasonable solution, so #350 will also be closed. Scala docs: https://docs.scala-lang.org/scala3/guides/migration/tutorial-macro-mixing.html#3-cross-validate-the-macro
This will be released together with SLF4J 2.x, Logback 1.5.x, and Java 21 in
4.0.0-RC.1. This is considering that these dependencies are all versions that have been released for a long time. After stabilization, it will be released to version 4.0.0 and will only be developed on version4. x. Therefore, the3.xbranch only supports vulnerability fixes for non-destructive dependencies.