Sometimes, we need to use a complex type in several places. Rather than keep repeating the function type or the complex generic setup, we can use a type alias to provide a "shorthand" way to reference the type.

Setting up a type alias is a matter of using the typealias keyword, followed by your desired name, =, and the type to be represented by that name.

Then, elsewhere in your code, you can use the alias' name instead of the type itself.

• the documentation
• Elements of Kotlin