I m tinkering with tests in Meta It looks like `data class` kotlinlang #arrow-meta

@Test
  fun `destructuring example`() {
    assertThis(CompilerTest(
      config = {
        metaDependencies
      },
      code = {
        """|data class Person(val firstName: String, val lastName: String, val age: Int)
           |
           |val person = Person("Matt", "Moore", 100)
           |val (firstName, lastName, age) = person
           |""".source
      },
      assert = {
        allOf(
          "firstName".source.evalsTo("Matt"),
          "lastName".source.evalsTo("Moore"),
          "age".source.evalsTo(100)
        )
      }
    ))
  }

The code snippet fails to compile. Removing the

data

keyword succeeds, but then there are no

componentN

functions generated for destructuring.

Ran the test individually and seeing this:

Copy code

e: /var/folders/d4/jb8hn0bj4g3f1kgvrf5p19tw0000gn/T/Kotlin-Compilation4522202210550990282/sources/Source.kt: (31, 5): Destructuring declarations are only allowed for local variables/values

I also found other examples where

data class

is used. So I must be doing something wrong here. I'll keep looking.

Nevermind. It's a case of standard Kotlin here. You can't destructure at the top level. This is just following the same rules.

raulraja

05/25/2020, 11:45 AM

This is a bug most likely, try disabling the lens plugin if it’s still active in the etaPlugin, it may be interfering

also the identity template of data class may be wrong and it’s not considering all ellements

we had to add a hack at some point in meta to print the data modifier

leave just your plugin and the proofs plugin in MetaPlugin

also you can check in those other plugins uncommented as the lens plugins is unfinished and the comprehension one and others may not be necessary after all

mattmoore

05/25/2020, 5:02 PM

Removing lens plugin worked. I was also able to get it to work with lens enabled by adding optics dependency:

Copy code

config = { metaDependencies + addDependencies(arrowOptics) }