Let's clarify some points for folks not so familiar with Scala.
> * Scala minor version are binary incompatible, so maintaining Scala projects is a big pain. Upgrading Spark from Scala 2.11 to Scala 2.12 was a massive undertaking for example.
Scala just chose a strange naming scheme. Other languages would have just increased their major version instead. The scala minor version is increased every few years and not every month or so.
> * Scala has tons of language features and lets people do crazy things in the code.
Actually, that's not true. Or rather: compared to what language?
Scala has surprisingly few language features, but the ones it has are very flexible and powerful. Take Kotlin for example. It has method extensions as a dedicated feature. Scala just has implicits which can be used for method extension.
> * Scalatest is stil used by most projects and is annoying to use, as described here: https://github.com/lihaoyi/utest#why-utest. The overuse of DSLs in Scala is really annoying.
I agree with the overuse of DSLs. Luckily that got much better, but older libraries like scalatest still suffer from that.
> * Li's libs (os-lib, upickle, utest) have clean public interfaces, but most Scala ecosystem libs are hard to use, see the JSON alternatives for examples
I think that just comes from using the library in a non-idiomatic way. In most applications, you will need to use the whole json anyways, and then you use (or can use) circe like that:
{
"id": "c730433b-082c-4984-9d66-855c243266f0",
"name": "Foo",
"counts": [1, 2, 3],
"values": {
"bar": true,
"baz": 100.001,
"qux": ["a", "b"]
}
}
case class Data(
id: String,
name: String,
count: List[Int],
values: List[DataValue]
)
case class DataValue(
bar: Boolean,
baz: Float,
qux: List[String]
)
import circe.generic.auto._
import io.circe.parser._
val data = decode[Data]("...").get
data.copy(name = data.name.reverse).asJson
Yeah, that is more code, but as I said, in the vast majority for projects, you need all or most of the fields anyways, so all the structure definition is a one-time thing.
The advantage is that the last line is plain Scala code. You don't even need to understand the json-library to do transformations and re-encode into json.