Is there a way to call a non-context function from...

# getting-started

[Ruckus]

Is there a way to call a non-context function from within a context function of the same name?

fun generate(selection: Selection, values: Values) { ... }
context(Scope) fun generate(selection: Selection, values: Values) =
    generate([e-mail] refine selection, values)
       ^ this is a recursive call, but I would like to call the other (non context(Scope)) generate function

[Youssef Shoaib [MOD]]

Oh boy, that's a tough one. Currently, I think there's no way to remove receivers from a scope, which limits any neat solutions we can come up with.
Simplest workaround: have a bridge method:

fun generate(selection: Selection, values: Values) { ... }
private fun _generate(selection: Selection, values: Values) = generate(selection, values)
context(Scope) fun generate(selection: Selection, values: Values) =
    _generate([e-mail] refine selection, values)

[Youssef Shoaib [MOD]]

Here's a neat-ish solution that has a lot of overhead sadly (because it creates a function reference):

fun generate(selection: Selection, values: Values) {}

context(Scope) fun generate(selection: Selection, values: Values) {
    val generate: (Selection, Values) -> Unit = ::generate
    generate([e-mail] refine selection, values)
}

Interestingly, something like KT-44530 will remove that overhead (which, shameless plug, I've been working on a compiler plugin for, but I haven't yet updated to 1.6.20)

[Youssef Shoaib [MOD]]

Overheadless solution: define a few utility functions that invoke without a context like-a so:

fun generate(selection: Selection, values: Values) {}

context(Scope) fun generate(selection: Selection, values: Values): Unit = 
    invokeContextless(::generate, /*this@Scope,*/ [e-mail] refine selection, values)

inline fun <A, B, R> invokeContextless(action: (A, B) -> R, a: A, b: B): R = action(a, b)
inline fun <A, B, C, R> invokeContextless(action: (A, B, C) -> R, a: A, b: B, c: C): R = action(a, b, c)

The compiler seems to understand which function you intend by that function reference based on the amount of parameters that you pass to invokeContextless, try that out yourself by uncommenting the this@Scope .
Personally, this is a well-balanced solution in that it's concise enough but it doesn't sacrifice performance. I would've preferred however if instead the function reference solution would've had no overhead, or if we could get a way to remove receivers from a scope

[Ruckus]

Indeed. I think I'll stick with the utility function approach for now, but I'll definitely keep an eye on that plugin. Thanks again for the help.