effect Logger { fn log(level: String, msg: String): Unit fn getLevel(): String } fn processData(data: Int): Int with {Logger} = { Logger.log("info", "Processing data...") let result = data * 2 Logger.log("debug", "Result computed") result } handler consoleLogger: Logger { fn log(level, msg) = Console.print("[" + level + "] " + msg) fn getLevel() = "debug" } fn main(): Unit with {Console} = { let result = run processData(21) with { Logger = consoleLogger, } Console.print("Final result: " + toString(result)) } let output = run main() with {}