A Java geek

Java streams and state

With Java 8 streams, it seems Functional Programming has won. Long live statelessness and recursion! Reality is a bit more nuanced: as always in software programming, it depends. I believe that the more tools in your toolbelt, the better it is. When all you have is a hammer, everything looks like a nail. In Functional Programming, every function needs to be pure: output only depends on input, and there are no side-effects.

Development

From Imperative to Functional Programming: a grouping issue (and how to solve it)

This is the 3rd post in the From Imperative to Functional Programming focus series. There’s a whole category of problems related to grouping e.g.: Given a collection of person, return a list of pairs with the first value the age, and the second one the collection of persons of that age. Given a collection of orders, return a list of pairs with some price range e.g. $0-$100, $101-$200, etc. as the first value, and the number of such orders as the second one.

Development

From Imperative to Functional Programming, an approach

This is the 2nd post in the From Imperative to Functional Programming focus series. Last week, we ported the migration of a Scala application from imperative to functional in Kotlin with the help of the Arrow library. This was pretty easy: the example was laid out for us. This week, I’d like to go for more fundamental stuff.

Development

From Imperative to Functional Programming using Arrow

This is the 1st post in the From Imperative to Functional Programming focus series. Some time ago, I watched the talk FP to the max. While the end of the talk is quite Scala-ish, the beginning can be of interest regardless of the language. In the talk, the speaker tries to migrate a standard imperative-like application using a functional approach. I wanted to check if it was possible to do the same in Kotlin.

Development

Git service providers comparison

Since its inception, the attitude of GitHub toward repositories was to allow unlimited public repositories, while make private ones paying. Whether it’s a consequence of Microsoft’s acquisition or not, this stance changed recently: GitHub announced private repositories were also made free, for up to 3 contributors. There was a lot of celebration on the Web, but not from my side. This move looks more like a (desperate?) move to keep developers on GitHub.

Development

The sieve of Eratosthenes

Recently, I stumbled upon a Reddit thread pointing to a repository comparing the performances of implementations of the Sieve of Eratosthenes in different languages. The results were, let’s say, intriguing. The worst surprise came from Kotlin. I couldn’t believe my eyes! Then, I looked at the code.

Java

OpenJDK 11, tools of the trade

In my talk about the Security Manager, I demo an attack using the Attach API. The later requires to know about the PID of the JVM one wants to attach to. Because my good friend Evegeny Mandrikov couldn’t attend the talk at Devoxx Ukraine, I did a private demo just for him. To get the PID of the JVM I wanted to attach to, I used the 'ps -ef | grep java' command.

Programming

Learning Clojure: transducers

This is the 8th post in the Learning Clojure focus series. This week, the subject is transducers. But before diving into that subject, we first need to talk more about reducers. If you have some experience in Java 8, you probably already know about the Stream.reduce() function. It’s available in three different flavors.

Java

A hard look at the state of Java modularization

When Jigsaw was released with Java 9, it was the end of a long process - it had been postponed already - and it had to be released. With the coming of Java 11, the latest Long-Term Support, I think it’s a good time to take a snapshot of the state of modularization.

A Java geek

Nicolas Fränkel's blog