cats.implicits._ -> cats.syntax.all._

[armanbilge]

It's about damn time!

[satorg]

thank you 👍

[satorg]

Hmm.. That looks quite odd. As I understand, these two imports should not be required to happen simultaneously. So if they are required then perhaps some implicits are missing from the cats.syntax.all._ path.

[armanbilge]

So if they are required then perhaps some implicits are missing from the

No, odd but correct. How can you resolve this implicit with only the syntax import?

cats/binCompatTest/src/main/scala-2/catsBC/MimaExceptions.scala

Line 33 in ccd576f

cats.Monad[cats.data.OptionT[List, *]],

The syntax imports only work if you use the syntax :)

[satorg]

Hmm... Not sure, what do you mean. This particular example does not require any additional imports to compile.
Because Monad for OptionT is picked up from the OptionT's companion, apparently.
Whereas Monad[List] is picked up from the Invariant's companion automatically:

cats/core/src/main/scala/cats/Invariant.scala

Lines 138 to 139 in ccd576f

	implicit def catsInstancesForList: Monad[List] with Alternative[List] with CoflatMap[List] =
	cats.instances.list.catsStdInstancesForList

[satorg]

In any case, I don't think it is an obstacle to get this PR merged :) Thank you for cleaning the imports up!

[armanbilge]

Oh hm maybe I said a stupid :) and I was so sure I had it all figured out! let me take one more look at this.

[armanbilge]

Oh 🤦 it's because the whole point of this file, it to compile it against Cats v2.0.0, which pre-dates the re-organization that puts all implicits automatically in scope.

cats/build.sbt

Lines 265 to 271 in ccd576f

	lazy val binCompatTest = project
	.enablePlugins(NoPublishPlugin)
	.settings(
	useCoursier := false, // workaround so we can use an old version in compile
	libraryDependencies += {
	val oldV = if (tlIsScala3.value) "2.6.1" else "2.0.0"
	"org.typelevel" %%% "cats-core" % oldV % Provided

Ok, sorry, and thanks 😁

[armanbilge]

I decided to revert to cats.implicits for this one. The point is to make sure we don't break compatibility with old code, so it seems better to write that import the old way.

[satorg]

Yes, I think it makes sense, thanks!