Tutorials about the Scala programming language.
I’ve written this before, but when I saw this “pseudocode to Scala code” example in the book Functional Thinking, I thought it was worth mentioning again: If you have trouble grokking the Scala
map method, think of it as being named
transform instead. It transforms an input collection to an output collection, based on the algorithm you supply.
For those coming from the OOP world, I think “transform” is a better word because it is more meaningful, at least initially.
I’ll write about this a little more when I’m awake, but here’s a little look at ADTs implemented in Scala 2 (with traits and case objects) and Scala 3 enums.
“I though it was obvious, but apparently it's not. FP is not about not having side effects at all, otherwise it would be useless. It's just about deferring them for as long as possible, that's all.”
~ Alessandro Lacava, in this tweet
I wanted some specific features in a “find” utility, and when I couldn’t figure out how to get them with combinations of
awk, and other Unix commands, I wrote what I wanted in Scala. Those features are (a) showing matching filenames, (b) showing the line that matches my search pattern, and underlining the pattern in the output, (c) showing the line numbers of the matches, and (d) showing an optional number of lines from the file before and after each match.
Back when I was writing Functional Programming, Simplified I started to write a little Scala/FP “To-Do List” application that you can run from the command line, based on a similar application in the Learn You A Haskell For Great Good book. For reasons I don’t remember, I decided not to include it in the book, and forgot about it until I started using GraalVM (“Graal”) recently.
When you get started with functional programming (FP) a common question you’ll have is, “What is an effect in functional programming?” You’ll hear advanced FPers use the words effects and effectful, but it can be hard to find a definition of what these terms mean.