I’m still learning generics in general, trying to ...

# announcements

[Joshy Josh]

I’m still learning generics in general, trying to implement a generic builder pattern for the type safe builder approach. I currently have… `

fun <T> screen(init: T.() -> Unit): T = init as T

Then eventually extend it have bounds, but for now. I keep getting a casting error. I’m assuming because it’s not invoking init, but I can’t seem to figure that part out.

[Joshy Josh]

essentially, I will have a class call this function like: `

fun class(init: MainView.() -> Unit) = screen(init)

[Joshy Josh]

It appears to work as:

fun <T> screen(obj: T, init: T.() -> Unit): T {
    obj.init()
    return obj
}

then invoking with

fun(view: MainView.()-> Unit) = screen(MainView(), view)

simply because I’m sending in the object. Is there a better approach so I don’t have to explicitly send in the MainView() to the generic builder?

[Jakub Pi]

https://kotlinlang.org/docs/reference/type-safe-builders.html

[Jakub Pi]

You'll want to invoke screen with a closure. So either screen { /* code here */ } or screen(MainView()) {/* code here */ }

[Jakub Pi]

The reference has examples of both.. You can also look at the buildString source code.

[Joshy Josh]

Thank you!