I have been supporting an extension for Visual Studio Code for about a month now. In that time I have learned a lot about building extensions for an editor and static analysis of Javascript. Today is more about the former and less about the latter. Nevertheless, I have found that creating snippets, modifying the status bar and displaying messages is trivial, but modifying the current document is hard when you don’t know how to even get started.

Last post we discussed union and intersection of sets. These two functions are common and well used, so they are quite important to understand at a deep level, especially if you work with databases on the regular. It can also be helpful to understand these behaviors if you have lots of sets of simple data which need to be combined in a straightforward way.

Last week we talked about sets and how they relate to arrays. This week we will take a look at how to interact with arrays and apply two common mathematical operations on them to produce new, refined sets of data with which we can interact.

I’ve had conversations with a programmers with varied backgrounds and experience levels. One thing which has come up in several conversations is math, and how much math a programmer needs to be effective. I have a formal background in math, so I tend to lean heavily on the side of more math is better. Other programmers argue that only select topics in math are important to make a professional programmer effective.

I started writing a Visual Studio Code extension about two and a half weeks ago and, as is little surprise, writing an extension with new, uncharted functionality takes more knowledge than you can find in the basic tutorial for creating a hello world extension. As I learned, I thought, I should write what I learned down so other people would have a little more illumination than I had.

About a month ago, I started working at Hunter. Now, I have been pretty aware of refactoring, design patterns, good practices and common practices. I don’t always agree with what everyone else says or does, but I typically have a good reason to do it the way I do. For whatever I do, Hunter does more so. I am a notorious function extractor and deduplicator, but never more than what I have seen or done in the last month, or until now.

It’s really great to see functional patterns become more accepted since they add a lot of really powerful tools to any programmer’s toolbox. Unfortunately, because functional programming was relegated primarily to the academic world for many years, there aren’t as many professional programmers who have developed a strong feel for good patterns and share them with more junior programmers. This is not to say there are none, but it is important to note that most programmers think of functional programming and say “it has map, filter and reduce; it’s functional.”

I usually write something meaty for my posts, but sometimes it’s worthwhile to just see some of the strange stuff you can do with a language because it’s informative. I remember one of the most enlightening things I experienced while I was working on my degree was taking a class on Assembly. I don’t use Assembly at all in my day to day, but there was a lot of good knowledge I gained just from taking the class.

A while back we discussed composing functions together to blend behaviors and extend functions to solve more complex problems. The discussion was all about composing two specific functions together. In functional programming composing multiple functions together can actually be part and parcel of the entire new function.

In the time I have written and mentored with Javascript, there is a single core concept which seems to give people a significant amount of trouble: bind. To the uninitiated, bind is a puzzle, wrapped in a mystery wrapped in an enigma. If you are comfortable with functional programming, there are parts of bind which make no sense and, at the same time, if your experience is rooted in a strict OO language, other aspects will be less than sensible. I’d like to look at bind holistically in the hope that all will become clear.