How to define new operator in Kotlin?

Question

Is it possible to define a generic exponentiation operator that can be interfaced like this:

> 10^3         // 1000
> 2.71^2       // 7.3441
> 3.14^(-3.14) // 0.027..

According to the docs it's possible to extend classes with infix functions:

// Define extension to Int
infix fun Int.exp(exponent: Int): Int {
...
}

But they don't allow symbols like ^

Answer 1

Unfortunately, you cannot define new operators, there's only a predefined set of those that can be overloaded. Some operators might be added to this set later, there's an open issue for that in the Kotlin issue tracker.

However, you can use backticked names to define infix extension functions which look like operators (much less pretty though):

infix fun Int.`^`(exponent: Int): Int = ... 

Usage:

5 `^` 3

Note that infix functions have precedence lower than that of operators, thus

1 + 1 `^` 3 == 8