File naming conventions for Kotlin

Question

Kotlin removes the Java "one top-level public class per file" restriction, which I've learned to love. I wonder if there are reasons for this discussed somewhere and whether there are some guidelines how to deal with this new freedom?

Answer 1

You can still use that Java rule as a convention and name your files after your classes. Or you can start putting more classes into a single Kotlin file, in which situation I'd recommend naming the files after their purpose. Each file will usually contain classes or other top-level elements that are related to each other (if they are not, maybe they don't belong to the same file in the first place?). There should be single word or a small number of words that express the purpose of all the classes in a single file, which is then a natural candidate for the file name.