Callbacks

I want to show how to do callbacks in Golang although many say that callbacks are not idiomatic in Golang

Callbacks)

a callback is any executable code that is passed as an argument to other code, which is expected to call back (execute) the argument at a given time.

There are two types of callbacks, differing in how they control data flow at runtime:

1. Blocking callbacks (also known as synchronous callbacks or just callbacks)

2. Deferred callbacks (also known as asynchronous callbacks).

3. Blocking callbacks are invoked before a function returns

4. Deferred callbacks may be invoked after a function returns.
   • Deferred callbacks are often used in the context of I/O operations or event handling,
   • Deferred callbacks are called by interrupts or by a different thread in case of multiple threads.
5. Due to their nature, blocking callbacks can work without interrupts or multiple threads, meaning that blocking callbacks are not commonly used for synchronization or delegating work to another thread.

package workshop

func average(numbers []float32, cb func(float32) float32) float32 {
    var sum float32
    for _, val := range numbers {
        sum += cb(val)
    }
    return sum / float32(len(numbers))
}

func callbacks() {
    nums := average([]float32{1.0, 2.0, 3.0, 4.0, 5.0}, func(n float32) float32 {
        return n
    })
    assert(nums == 3.0)
}

Notice here that the average function takes 2 parameters numbers which is a list of float32 and a function Also notice that the name cb is used for the cb function and all it does in the average function is return n

Callbacks in Golang