Learning Golang (some rough notes) - S01E04 - Function Closures

👉 A Tour of Go : Function Closures

So far the Tour has been 🤔 and 🧐 and even 🤨 but function closures had me 🤯 …

Each of the words on the page made sense but strung together in a sentence didn’t really make any sense to me.

Google resources threw up some nice explanations:

• https://gobyexample.com/closures

  I like this site as it links all its examples to The Go Playground where you can try out each code block

• http://tleyden.github.io/blog/2016/12/20/understanding-function-closures-in-go/

  This comment was particularly useful

  Essentially you can think of them like stateful functions , in the sense that they encapsulate state.

  It made things click a bit for me, more than the abstract alphabet soup that other examples used :)

This one gets into some more hands-on examples

• https://www.calhoun.io/5-useful-ways-to-use-closures-in-go/

It also acted as a spoiler for the function closure exercise since that was the first example it gives :)

func fibonacci() func() int {
    f1 := 1
    f2 := 0
    return func() int {
        f1,f2 = f2, (f1+f2)
        return f1
    }
}

I tweaked the version that I’d seen so that the return values stated at zero

0 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181