Function withPrefix

test/README.example.proof.ts:1147–1159

(prefixFactory: (level: LogLevel) => string)

  const logError = logEffect("error");

  function withPrefix(prefixFactory: (level: LogLevel) => string) {
    return defineHandlerFor<Logging>().with((self) =>
      self.handle(
        (name): name is Logging["name"] => typeof name === "string" && name.startsWith("logging."),
        function* ({ effect, resume }): Generator<Logging, void> {
          const prefix = prefixFactory(effect.name.slice("logging.".length) as LogLevel);
          effect.payloads.splice(0, 0, prefix);
          yield effect;
          resume();
        },
      ),
    );
  }

  function withMinimumLogLevel(level: LogLevel | "none") {
    return defineHandlerFor<Logging>().with((self) => {