Are there any programming languages that support state machines in their standard library?

State machines are a fundamental computer science concept and in many senarios they are the simplest way to implement a process or program. However, most programming languages don't support them natively. Is there a technical limitation to do it? And if not, are there any programming languages that do support state machines in their standard libraries?

A state machine is basically a loop around a switch case construct, which exists in pretty much almost every language I know in a form or another.

So I'm curious of the one languages you found out that do, according to your wording, implement state machines natively, since to me most of all do so.

StackExchange Computer Science Q#145340, answer score: 2