A Week with Go, Day 3

The first two days of tinkering and scouring helped me form an opinion of Go based on its syntax. To form a more-informed opinion I would have to write some more code and see how much resistance I experienced along the way. What features were missing? How was typing applied? I wrote a rudimentary version of Deal or No Deal, and slowly some of those meaningless sections in the language spec started taking on more meaning.

I decided to store the case amounts as an integer array (nobody likes the 0.01 anyway!) and came across my first bit of frustration and misunderstanding when it came time to shuffle the amounts.

cases = []int{100, 200, 300, 400, 500, 750, 1000,
    5000, 10000, 50000}
shuffle(cases)

func shuffle(arr []int) {
        rand.Seed(time.Nanoseconds())
        for i := len(arr) - 1; i > 0; i-- {
                j := rand.Intn(i)
                arr[i], arr[j] = arr[j], arr[i]
        }
}

The language spec says arrays are value types and slices are reference types. shuffle was doing what I wanted, but why was Go manipulating the array values if cases was supposed to be passed by value? I posted the question on Stack Overflow and it became clear that cases was a slice. I had written []int{} expecting the behavior of [...]int{}. Hopefully this will be the first and last time I make this mistake, but I have a feeling it won't be even with a correct understanding of what Go is doing. The syntax is just too similar. I don't understand why almost identical syntax was chosen for two different concepts here but different syntax was chosen for identical concepts with var = vs :=.

And I was lucky I only needed to shuffle a list of integer values; Go doesn't have generics, so I wouldn't be able to easily write a general-purpose shuffle function. It feels "dirty" to write shufflei(arr []int), shufflef(arr []float), etc. since the functions would all be identical except for their signatures!

The appeal of clean-looking code, novel looping, and an official formatting utility was waning because of issues and deficiencies more integral to the language and its implementation. Go is still nascent, but we shouldn't be revisiting these problems in a modern programming language.

Feel free to share your impressions of Go in the comments below and come back tomorrow for day 4. If you're interested, here's my Deal or No Deal code.