Problem Statement

Imperative programs like to jump around, but some languages restrict these jumps. Many structured languages restrict their conditional structures and loops to local jumps within a function. Some assembly languages limit certain jumps or branches to a small range. This task is to demonstrate a local jump and a global jump and the various other types of jumps that the language supports. For the purpose of this task, the jumps need not be used for a single purpose and you have the freedom to use these jumps for different purposes. You may also defer to more specific tasks, like Exceptions or Generator. This task provides a "grab bag" for several types of jumps. There are non-local jumps across function calls, or long jumps to anywhere within a program. Anywhere means not only to the tops of functions! These jumps are not all alike. A simple goto never touches the call stack. A continuation saves the call stack, so you can continue a function call after it ends.

Use your language to demonstrate the various types of jumps that it supports. Because the possibilities vary by language, this task is not specific. You have the freedom to use these jumps for different purposes. You may also defer to more specific tasks, like Exceptions or Generator.

Let's start with the solution:

var func = Fn.new {
    for (i in 1..10) {
        if (i == 1) continue // jumps to next iteration when 'i' equals 1
        System.print("i = %(i)")
        if (i > 4) break     // exits the loop when 'i' exceeds 4
    }
    for (j in 1..10) {
        System.print("j = %(j)")
        if (j == 3) return   // returns from the function when 'j' exceeds 3
    }
}

var fiber = Fiber.new {
    System.print("starting")
    Fiber.yield()            // yields control back to the calling fiber
    System.print("resuming") // resumes here when called again
    Fiber.abort("aborting")  // aborts the script
}

func.call()                  // calls the function
fiber.call()                 // calls the fiber
System.print("yielding")
fiber.call()                 // resumes the fiber
return                       // would exit the module (and script) without error but won't be reached