as it's possible to have multiple context elements...

# language-evolution

[Gilles Barbier]

as it's possible to have multiple context elements context(A, B) , it would be convenient to have mutliple elements in with: with(a, b) { ... }

[Fergus Hewson]

There is only one this. You could merge them together if a/b are both abstract/interfaces.

[Chris Lee]

Perhaps you are looking for the upcoming context parameters feature?

[CLOVIS]

@Fergus Hewson you can have any number of this , even right now:

class Foo {

    fun showFoo() {
        println(this)
    }

    inner class Bar {

        fun showBar() {
            println(this)
        }

        fun exec() {
            with(Baz()) {
                showFoo()
                showBar()
                showBaz()
            }
        }
    }

    class Baz {

        fun showBaz() {
            println(this)
        }

    }
}

Foo().Bar().exec()

[Fergus Hewson]

Thanks for the clarification

[Jokubas Alekna]

This would require vararg type parameters to be added. I think the Kotlin team mentioned that they had a prototype for this feature, so it might be coming in a future language version

[CLOVIS]

There are many ways to do this, with various amount of language support. One option in the KEEP was to create a new keyword to inject a value into scope:

fun foo {
    with LoggerScope()
    <http://log.info|log.info> { "Test" }
}

Compared to the with(a, b) approach, this has the benefits that:
• No need to invent a new concept of n-ary type parameters (which are a very complex can of worms)
• This is purely syntax sugar, so there is no need for binary compatibility or anything else
• Doesn't force us to introduce a new indentation level each time we want to add something in the context