Styleguide

General

We primarily use Kotlin and follow the standard coding conventions outlined in https://kotlinlang.org/docs/reference/coding-conventions.html

The following outlines the most important aspects.

Formatting

• Place curly braces in the end of the line where the construct begins and the closing brace on a separated line aligned vertically with the opening construct.

if (elements != null) {
    for (element in elements) {
        // ...
    }
}

Horizontal whitespace

• Put spaces around binary operators (a + b)
• Do not put spaces around unary operators (a++)
• Put spaces between control flow keywords (if, when, for and while) and the corresponding opening parenthesis.
• Put a space after //: // This is a comment

Colon

Put a space before : in the following cases:

• when it's used to separate a type and a supertype
• when delegating to a superclass constructor or a different constructor of the same class
• after the object keyword

Don't put a space before : when it separates a declaration and its type.

abstract class Foo<out T : Any> : IFoo {
    abstract fun foo(a: Int): T
}

class FooImpl : Foo() {
    constructor(x: String) : this(x) {
        //...
    }
    
    val x = object : IFoo { ... } 
}

Annotation formatting

Can be discussed

Documentation comments

• For longer documentation comments, place the opening /** on a separate line and begin each subsequent line with an asterisk
• Start the sentence with an upper case letter, unless the grammar forbids.
• Finish the comment with a point.

/**
 * This is a documentation comment
 * on multiple lines.
 */

Short comments can be placed on a single line:

/** This is a short documentation comment. */

Source file organization

Class layout

Use a single class per file, unless otherwise required (e.g. for sealed classes and their sub-classes)