IT Sky Consulting GmbH
On 2019-12-02 I visited the conference reClojure. This was an admirable community effort to create a replacement for ScalaExchange, which simply did not happen because of the bankruptcy of Skillsmatter. There was only one track, so the schedule is exactly what I visited. I will just copy it below, because schedules from conference sites usually …
„Visit to reClojure in London 2019“ weiterlesen
It has been written here that HTML-entities (these ä etc) should be avoided with the exception of those that we need due to the HTML-syntax like <, >, & and maybe " and . They were already mostly obsolete more than 20 years ago, but in those days we still did not automatically use UTF-8 …
„How to get rid of these HTML-entities in Files“ weiterlesen
In 2019 I visited Devoxx UA in Kiev and Devoxx BE in Antwerp. Traveling was actually a little story by itself, so for now we can just assume that I magically was at the locations of DevoxxUA and DevoxxBE. In Kiew I attended the following talks: Probabilistic data structures in nutshell (in Ukrainian) [Oleksandra Kulyk] …
„Devoxx UA and Devoxx BE 2019“ weiterlesen
The company Skillsmatter in London has been put „under administration“ and basically stopped its operations. The web site seems to suggest, that everything is still ok, but that is not the case and I have heard so from several sources. The owner Wendy Devolder writes on Twitter and on Linkedin. Or here are some more …
„Company „Skillsmatter“ stops operations“ weiterlesen
In Java it is possible to declare a method with a „throws“-clause. For certain exceptions, that are not extending „RuntimeException“ or „Error“, this is actually required. What looked like a good idea 25 years ago has proven to be a dead end. I do not know of any other major programming language that opts for …
„Checked Exceptions in Java“ weiterlesen
Sometimes it is conveniant to use exceptions for implementing the regular program logic. Assuming we want to find some data and then process them. When no data is found, this step can be skipped, because there is nothing to do. So we could program something like this: public Data readData(Param param) { Data data = db.read(param); if (data.isEmpty()) { throw new NotFoundException(„nothing found“); } return data; } public ProcessedData doWork(Param param) { …
„Exceptions to implement Program Logic“ weiterlesen
Some commonly used languages have been quite well designed or at least would have been considered so at the time when they appeared. Even if they have their weaknesses, they should be good for some purposes. Now beauty of programming languages is highly subjective. So I do not claim any universal truth to this. But …
„Accident Languages“ weiterlesen
UUIDs have proven useful in many circumstances. We have basically two main variants: The UUID is calculated as a combination of the Ethernet-MAC-address, the timestamp and a counter. The UUID is calculated using a good random number generator While variant 1 provides for a good uniqueness, there are some issues with it. Today we use …
The functions sqrt and sometimes even cbrt are commonly available, but it is nice to see how they can be calculated. There are several approaches, but the most popular ones are Newton’s method and an algorithmic formulation of how roots are taken manually, for those old enough to still have learned it in school. Earlier …
„How to calculate Square Roots and Cubic Roots“ weiterlesen
When we write APIs, that have parameters or as return values, it is a good idea to consider relying on immutable objects only. This applies also when collections are involved directly or indirectly as content of the classes that occur as return values or parameters. Changing what is given through the API in either direction …
„Guava-Collections in Java-APIs“ weiterlesen