When I have a function that expects a value of type ` A gt B kotlinlang #compiler

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Title

s

Sam

07/29/2022, 7:58 AM

When I have a function that expects a value of type

(A) -> B

, it’d be cool to be able to just pass

::foo

instead of

A::foo

. Is there a name for what I want? Even better, is there an existing ticket/proposal for it? Example:

data class A(val name: String)
fun <B> A.getProp(prop: (A) -> B) = prop(this)
fun A.getName() = getProp(::name) // I want this
fun A.getName2() = getProp(A::name) // But I have to do this instead

The context where this bugs me is in tests using

assertk

, where I end up with things like:

assertThat(actual)
    .isInstanceOf(ExpectedClass::class).all {
        prop(ExpectedClass::a).isEqualTo(expectedA)
        prop(ExpectedClass::b).isEqualTo(expectedB)
    }

I end up repeating the

ExpectedClass

over and over again

But I keep doing it because it is useful to use the property reference rather than a lambda (like

prop { it. a }

), so that when the assertion fails it will include the name of the property

c

Chrimaeon

07/29/2022, 8:18 AM

Better post in #language-proposals

s

Sam

08/04/2022, 7:48 AM

👍 thanks for the suggestion, will do!

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