Yesterday I have found this interesting question on Stack Overflow asked by Opal. He faced some unexpected compilation errors when dealing with Java generics and Vavr library. It turned out the root cause of the issue there was not the library, but Java compiler itself. This was pretty interesting use case and it motivated me to investigate it even further. This blog post reveals untold truth about Java generics type inference. Are you ready? :)
I guess you may heard about Groovy’s
Collection.each(Closure cl) method - it was introduced 15 years ago  and it was a great alternative for a good old for-loop, for-each or even using an iterator approach. You may also heard, that you should not overuse it, because creating a closure to do such simple operation like collection iteration is an overhead. But what if I tell you that nothing could be further from the truth - Groovy’s
each method may be faster than iterator or Java’s for-each. Sounds interesting? Enjoy the reading!
One of the first mistakes people do when starting their journey with Java programming language is using
== to compare objects instead calling
a.equals(b). When you begin playing around with Groovy you quickly notice that equal operator
== is used to compare objects in place of calling
a.equals(b). "Finally something more intuitive!" you might think. In today’s article we will dig a little bit deeper to learn avoiding problems equal operator in Groovy may produce.
Some time ago I have found another interesting Groovy related question on Stack Overflow. This time someone was asking about static variants of popular
methodMissing methods. The official Groovy documentation does not explain how to do it - it only explains how to add any static method through
metaClass. Today we are going to learn how to define these methods in two different ways.
Groovy is a very powerful language on a JVM platform and with this great power comes great responsibility. There are many language features that are not intuitive for many people that start using Groovy. One of these features is dynamic coercion and type promotion which may cause you a headache if you use it carelessly.
Some time ago I have found a very interesting question on Stack Overflow about forbidden characters in Groovy script filenames. Let’s use it as an excuse to make a closer look at Groovy script files naming limitations - you will find out that there are none actually.
If you use Groovy for scripting or other similar tasks you probably faced a situation where you get an input as a text and you need to process it e.g. split by some delimiter and continue working with extracted values. In this post I will show you how to do it in 3 different ways.
Some time ago I was interviewed to one of the Java-based projects and I was asked to solve this pretty interesting puzzle. The question was "how to count frequency of a digit in a factorial of number, let’s say 1000". I tried to solve it using Java 8 Stream API, but I guess you see how bad decision it was. Problems like that can be easily solved with pure functional languages and today we are going to find out how to solve this puzzle with Haskell.