Is there any notion of introducing some kind of algebraic effect system with arrow meta like with Frank, Unison, or some of the Haskell libraries like Freer-Simple? I’d be very interested in something like that 👀

I'm curious: Has anyone tried making use of kotlinpoet for codegen in an arrow meta plugin? I am attempting to do this currently -- yet am having some issues with the interactions between the Psi API and kotlinpoet. Asking on the kotlinpoet repo I've found some help with this issue, but I was thinking if there's anyone else who has tried this in arrow meta, I might be able to dog up some more helpful examples/utilities.

Hey. Does anyone have a working example of using Arrow-Meta with Kotlin 1.5.3 I could take a look at? I'm having tremendous build issues trying to get this working. Thanks.

Hey, I’m trying to run the optics compiler plugin with 3rd party generated code. The tricky part is that I don’t have control over the 3rd party generated code so I can’t add

@optics

annotation to the data classes. I started creating custom plugin based on the optics compiler plugin, so I can look for the classes that I want (e.g.

is a data class && it's in specific location

) but that doesn’t seem like the right thing to do. What would you suggest for the 3rd party code? pp. I’ve managed to generate some code, but then I stumbled upon errors such as unresolved references etc.

Hello. Does anyone have any examples they could point me to for a gradle project (either groovy or .kts) making use of the arrow proofs plugin? I understand it is not yet released just yet -- but I wanted to try it out for myself before then in some of my projects. I know there are tests showing how the plugin is used in the arrow-meta repository, but I am trying to figure out how to use the plugin in an actual standalone gradle project.

Hey all. I've finally got my first arrow-meta plugin to the point where I'm ready to depend on it in other projects. I've tried to copy the structure of the plugins in the

arrow-meta

repo in order to setup a gradle plugin for loading my arrow-meta plugin, and I can build a jar for the gradle plugin fine -- but I'm not entirely sure how to test the result. Usually for a library I'd use

publishToMavenLocal

, and then use

mavenLocal()

as a repository in some other project to make sure the maven config is working properly. Is it possible to do the same for a gradle plugin? How would I set up maven to publish a gradle plugin? I tried skimming through the gradle files in the

arrow-meta

repo to see what would be of help, but no luck so far. Can someone point me in the right direction?

I have a question about what's possible (or what will be possible in the future) with compiler plugins: Java annotations have limitations as to what arguments they can take. For instance, annotations can't take functions as arguments. Would it be possible to have code like the following compile with a compiler plugin?

@Rule {
    if (parentOf(X,Y) && parentOf(Y,Z)
        grandparentOf(X,Z)
}

As it should be clear from the example here -- the idea for this is for a logic programming compiler plugin, and in particular, supporting anonymous top-level rules, rather than having to annotate e.x a top level function or val, which we would then have to name.

Hi all! I have a question about refined types plugin, are collections with primitive types acceptable in its compile time resolution? I'm trying to validade a simple predicate with a list:

val list = listOf(1)

data class FilledList private constructor(val value: List<Int>) {
    companion object : Refined<List<Int>, FilledList>(::FilledList, { ensure((it.isNotEmpty()) to "list cannot be empty") })
}

val filledList = FilledList(list)

And is popping:

val list = listOf(1) can't be verified at compile time. Use `Predicate.orNull(val list = listOf(1))` for safe access or `Predicate.require(val list = listOf(1))` for explicit unsafe instantiation

If I remove this list reference from the property and put its instance directly on FilledList invoke call site (

FilledList(listOf())

), nothing happens and its refinement occurs in runtime. I'm missing something or is not supported? If is not supported is there a typeclass / applicative or something that I can integrate with collections to make it work?

Another question but this time about Arrow Analysis, I'm trying to run in compile time a pre condition with collections, but I'm getting an error, I'm just trying to copy / paste the documentation example:

fun average(xs: List<Int>): Int {
  pre(xs.isNotEmpty()) { "list not empty" }
  TODO()
}

val x = average(listOf(1))

pre-condition `list not empty` is not satisfied in `average(listOf(1))`
  -> unsatisfiable constraint: `listOf(1).isNotEmpty`

The curious thing here is, pre / pos conditions with primitive values (like

PositiveInt

sample) works but not with collections, I've already tried to create value classes wrappers, Laws, but only works with primitive types, not collections... Am I missing anything? Current using Kotlin 1.6.10 and arrow analysis 2.0-SNAPSHOT

quick question, I saw there is a plugin for IntelliJ. However I cannot find it in marketplace (https://plugins.jetbrains.com/plugin/14291-arrow-meta). why?

Hi. I wonder what value does arrow-meta bring for writing backend IR plugins. I have not found any examples of such usage, only the api, from which it looks like there is not much invention here. Can someone point me why should I use arrow-meta over plain kotlin IR plugin or where are some docs/examples?

I just saw on the website that arrow proofs is no longer in development. What's the story there? Is the project totally scrapped? Delayed? Are we waiting for language/compiler infrastructure developments?

Trying to use Meta, and I get the error

Caused by: java.lang.AbstractMethodError: Receiver class package.MyMetaPlugin does not define or inherit an implementation of the resolved method 'abstract void registerProjectComponents(com.intellij.mock.MockProject, org.jetbrains.kotlin.config.CompilerConfiguration)' of interface org.jetbrains.kotlin.compiler.plugin.ComponentRegistrar.

I assume it is something to do with the default implementation not getting picked up from Meta interface?

Is arrow meta now ready to be used in mpp context with IR?

Seen as 1.6.0 removes all the "quotes" extensions. Is there an updated example for the hello world example?

Ok, so I have checked out the last version that had the "quotes" extensions in, just to try and move my existing plugin over, and trying to replace stubbed functions like the hello world example Everything builds and runs and the plugin appears to be being called: -

val Meta.helloWorld: CliPlugin get() =
    "Hello World" { 
        meta(
            namedFunction(this, { true } ) { c ->
                println("remove")
                Transform.remove(c.element)
            }
        )
    }



@AutoService(ComponentRegistrar::class)
class MetaPlugin: Meta {
    override fun intercept(ctx: CompilerContext): List<CliPlugin> =
        listOf(helloWorld)
}

Are there any docs on getting started with arrow-meta IR? Can't find any. Also is arrow-meta MPP-ready yet?

What are the best ways to get started with Arrow Meta? I’ve gone over some medium articles but they’re all outdated and have old versions of the API

Hey, my knowledge of compilers is very limited, but the extra checks that arrow analysis provides seem very interesting. Is there going to be a maven compiler plugin as well? As I can only find gradle examples.

Hey everyone, do you have a list of required minimum/exact Kotlin and Gradle versions for Arrow Analysis? I'm running into class not found after applying the plugin

* What went wrong:
org/gradle/util/internal/VersionNumber
> org.gradle.util.internal.VersionNumber

Changing the Gradle version to 7.0.2/7.2/7.4 didn't solve the problem for me (this was suggested in a thread with the same problem).

Does arrow-meta provide any utils to resolve a type of

KtExpression

Hello. I'm trying to write a plugin, which counts size in bytes of data classes. In

irClass {...}

i'm modifying function body, but i don't know, how to return updated

irClass

😞

val Meta.GenerateShallowSize: CliPlugin
    get() = "Generate shallowSize method" {
        meta(
            classDeclaration(this, { element.isData() }) { declaration ->
                Transform.replace(
                    replacing = declaration.element,
                    newDeclaration =
                        """|$`@annotations` $kind $name $`(typeParameters)` $`(params)` : $supertypes {
                           |   $body
                           |   fun shallowSize(): Unit
                           |}""".`class`
                )
            },
            irClass { clazz ->
                {
                    val function = clazz.functions.find { it.name.asString() == "shallowSize" }!!
                    with(DeclarationIrBuilder(pluginContext, function.symbol)) {
                            function.body = irBlockBody {
                                irInt(clazz.fields.map { it.type.byteSize() }.sum())
                            }
                    }
                    return clazz.
                }
            }
        )
    }

Does Arrow-Meta support front end source code generation at all at the moment with the removal of the quotes system? I was using it for source code generation and it's looking like I should migrate away from arrow-meta if quotes was removed without a replacement.

Hey 👋 I wanted to try out the new arrow-analysis plugin in one of my projects, but seem to be getting an internal exception

kotlin.NotImplementedError: An operation is not implemented: Missing impl for throw RuntimeException(ex) .../DatabaseConfiguration.kt (org.jetbrains.kotlin.psi.KtThrowExpression)

Hello again 😄 I’ve been experimenting a little bit with arrow-analysis and I’m wondering whether I could change something in this example for the

v1 > v2 => Positive(v1) > Positive(v2)

and

Positive(v1) > Positive(v2) => Positive(v1).value > Positive(v2).value

implications to hold

In doing some experimentation I found something that is not very intuative:

@JvmInline
value class String5till10(val value: String) {
	init {
		require(value.length >= 5) { "String should be minimal 5 characters" }
		require(value.length <= 10) { "String should be maximum 10 characters" }
	}
}


// This works
val value = getRandomString()
if (value.length > 6) {
	if (value.length < 10) {
		StringExamples.String5till10(value)
	}
}

//This does not
val value = getRandomString()
if (value.length > 6 && value.length < 10) {
	StringExamples.String5till10(value)
}

Hi! I want to dynamically add (or replace) annotations to Methods. For example if I annotate a Method in my source like this:

@OneAnnotation(value = "someDetail")
fun methodA() { ... }

I want my plugin to add another annotation like this

@AnotherAnnotation(value = "someDetail") // value taken from "original" annotation
@OneAnnotation(value = "someDetail")
fun methodA() { ... }

Do you think arrow-meta is a good fit for this task? Any hints on how to do it?

Does ArrorMeta allow u to work with actual variables instances

Hi, what's the status of arrow-analysis? The 2.0 version officially promoted on the arrow website have some severe problems. Those are fixed in the snapshot versions. Will there be a stable release of 2.0.2 in the near future, or is there some blocker?