Is it possible to create a placeholder function or...

# random

[rtsketo]

Is it possible to create a placeholder function or template (or anything else) that will be replaced by the result of its code later on?
We need a temporary conversion function, let's say fun f(x: Int) = x * 15 + 30 so if we type f(10) in our code would be replaced with 180 later on (or even instantly).

Not sure if it's ok to ask here, it seemed to me too random of a question to ask anywhere else.

Edit: Even if it's possible somehow with the @Deprecated annotation, let me know.

[Tobias Berger]

I don't think there is some feature like that in Kotlin, however, you could just have a normal function and might be able to inline it later, using the Intellij refactoring feature.

[louiscad]

What's your use case?

[Matteo Mirk]

What you’re looking for is Macro support, which Kotlin doesn’t have.

[rtsketo]

@louiscad
Using measurements of a mockup design that are in pixels.
I've determined how I want to translate them in DP, so I need a way of converting them on the fly as I create the layouts programmatically.

[louiscad]

Honestly, making 2 integer operations is unlikely to slow your UI down. That said, if on Android or the JVM, I think R8 can inline all of that, essentially turning it into a constant.

[rtsketo]

I know, it's just that there's no point of keeping the function in the code after finishing up with the mockup. (The function will make no sense to a future developer that has no access to the mockup anymore).

[louiscad]

Then use the "Replace In Path" feature in the IDE (ctrl/cmd + shift + F).

[rtsketo]

What do you mean? How can you replace a function (which has a parameter) with its result like that?

[louiscad]

you replace f(10) by the actual known value

[rtsketo]

And do that for all values? 😝
Deprecating f and having it to be replaced automatically by the inner function (x * 15 + 30), I think it's a better solution.

[rtsketo]

So, what I did was to make a program that will evaluate the result of the function and replace the function call with it in all *.kt files in the specified dir (basically I automated Louis' answer). Thank you all for your help.