Hi all, having a compile-time-checked annotation ...

# arrow-meta

[Jörg Winter]

Hi all,

having a compile-time-checked annotation "Pure" is a wonderful idea.. although it seems difficult to introduce purity in a non-pure language like Kotlin.
But anyway.. wouldn't it be a better way to restrict allowed calls by having a white-list instead of a black-list ?
That way, one maybe could include the "domain" packages of an application (plus java.lang and similar.. if needed)
I am referring to this:
https://github.com/arrow-kt/arrow-reflection/blob/6b8caa1c21861eb8a753f155b76af326[…]-reflect-annotations/src/main/kotlin/arrow/meta/samples/Pure.kt
Of course this is currently a proof-of-concept anyway, if I understand correctly (?)... so my question is not a feature request in this sense.

[Javier]

As you said it is a proof of concept for the new incoming Arrow Meta infrastructure for compiler plugins but even if they are a proof of concepts we could keep a lot of them if they are used and any feature request is welcome 😄

[raulraja]

@Jörg Winter If you'd like to play with it we can change it to whatever makes sense including the name which it's currently a placeholder for an example. We can't really detect purity without accounting for conditional branches etc which we don't do now. We just do a deep search on binaries and local module for the current call graph and if we find things in the list we disallow it. It can be extended to also support throw and others