Main

The argument(s) this application was started with.

Unsafely exits the application.

Unsafely exits the process on non-throwable failures (onResult).

Wraps an effect for execution (interrupts, scope, etc.).

The exit code for a termination the runner treats as normal, when this is one.

An operator stopping the process is not a fault, so it must not be rendered, must not throw, and must not exit as a failure would. The default recognises none; KyoAppRunnerWithInterrupts recognises the interrupt it raised for a signal.

Handles the result of a registered effect block.

A termination normalTermination recognises is reported by neither channel: it renders nothing and exits with the code that supplies. An operator stopping the process is not a fault, so rendering and rethrowing it puts a stack-trace-shaped line on stderr for every ordinary stop.

Otherwise a value is rendered to standard output and a failure to standard error. The split is what an application's stdout contract requires: stdout is the program's output, and a failure is a diagnostic about the program, not output from it. A stdio server makes the cost of getting this wrong concrete, since every startup failure (a bad URL, a database refusing connections, a missing environment variable) put a non-JSON line on the very channel its host was parsing, and the host's first read of the connection was garbage. No discipline in the run block avoids it: this is the framework's own terminal reporting, reached by any failure the block does not catch. Every other application type wants the same split for the same reason, which is why IOApp reports an unhandled error to System.err.

A Throwable failure is rendered here and then rethrown, so the runtime's uncaught handler reports it a second time with its stack. Both copies land on standard error, and the second carries strictly more than the first.

Registers an effect to run when KyoAppRunner.runInitCode executes.

The main entrypoint to this application.

Runs all registered thunks in order.

Activation of the stats service providers happens first, so a classpath-present collector (kyo-stats-machine's host sampler, kyo-stats-otlp's exporter) is running before the application's own code starts producing the metrics it would otherwise miss. This is the entrypoint every kyo application funnels through, which is what makes classpath presence alone enough to activate.

The timeout for each registered effect block.

Thunks executed in registration order when the entrypoint runs.