Clarity is the smart contract language for the Stacks blockchain. It is interpreted (not compiled to EVM-style bytecode) and non-Turing complete, which means it forbids loops and recursion to ensure that all execution paths are finite and predictable.
clarity (define-public (hello-world) (ok "Hello, Stacks!"))
This predictability is known as 'decidability', allowing developers to know exactly how much gas a transaction will consume and what its outcome will be before broadcasting it to the network.