Skip to main content

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.

Comments

Popular posts from this blog

Geolocation Search

Services that allow users to identify nearby points of interest continue to grow in popularity. I'm sure we're all familiar with social websites that let you search for the profiles of people near a postal code, or mobile applications that use geolocation to identify Thai restaurants within walking distance. It's surprisingly simple to implement such functionality, and in this post I will discuss how to do so.

The first step is to obtain the latitude and longitude coordinates of any locations you want to make searchable. In the restaurant scenario, you'd want the latitude and longitude of each eatery. In the social website scenario, you'd want to obtain a list of postal codes with their centroid latitude and longitude.

In general, postal code-based geolocation is a bad idea; their boundaries rarely form simple polygons, the area they cover vary in size, and are subject to change based on the whims of the postal service. But many times we find ourselves stuck on a c…

Composing Music with PHP

I’m not an expert on probability theory, artificial intelligence, and machine learning. And even my Music 201 class from years ago has been long forgotten. But if you’ll indulge me for the next 10 minutes, I think you’ll find that even just a little knowledge can yield impressive results if creatively woven together. I’d like to share with you how to teach PHP to compose music. Here’s an example: You’re looking at a melody generated by PHP. It’s not the most memorable, but it’s not unpleasant either. And surprisingly, the code to generate such sequences is rather brief. So what’s going on? The script calculates a probability map of melodic intervals and applies a Markov process to generate a new sequence. In friendlier terms, musical data is analyzed by a script to learn which intervals make up pleasing melodies. It then creates a new composition by selecting pitches based on the possibilities it’s observed. . Standing on ShouldersComposition doesn’t happen in a vacuum. Bach was f…

Reading Unicode (UTF-8) in C

In working on scanner code for Kiwi I did a bit of reading up on Unicode. It's not really as difficult as one might think parsing UTF-8 character by character in C. In the end I opted to use ICU so I could take advantage of its character class functions instead of rolling my own, but the by-hand method I thought was still worth sharing. Functions like getc() read in a byte from an input stream. ASCII was the predominant encoding scheme and encoded characters in 7-8 bits, so reading a byte was effectively the same as reading a character. But you can only represent 255 characters using 8 bits, far too little to represent all the characters of the world's languages. The most common Unicode scheme is UTF-8, is a multi-byte encoding scheme capable of representing over 2 million characters using 4 bytes or less. The 128 characters of 7-bit ASCII encoding scheme are encoded the same, the most-significant bit is always 0. Other characters can be encoded as multiple bytes but the mo…