Hrvoje Nezic blog

SDEditGen is a preprocessor tool for Quick Sequence Diagram Editor, better known as sdedit. QSDE / sdedit is an excellent open source text to UML tool, but its syntax is not so nice: it is often unintutitive, cryptic, and hard to remember. Also, like syntax of many sequence diagram tools, sdedit’s syntax is unstructured. It is easy to create and read a Hello world (Bob → Alice) example, but it is much harder to write and read complex real-world diagrams. SDEditGen aims to provide a structured, nicer, easier and more intuitive syntax for sdedit. Read more

The PSClasses project provides classes with inheritance to PowerShell versions earlier than 5.0. PSClasses include important features of object-oriented languages, like following: class inheritance, overriding methods, calling overridden superclass methods, multiple constructors, calling other constructors of same class, calling superclass constructors. The library also contains an uncommon feature: automatic generation of the constructor which accepts arguments corresponding to all instance variables. This feature resembles case classes in Scala or data classes in Kotlin. Read more

The article describes several ways of chaining unary functions most relevant for Reader monad and proceeds with a summary of Reader monad functionality in Cats library: it presents basic methods like pure, ask, map, andThen, local and flatMap. The flatMap example is presented in several variants, both with and without a Reader. The article then includes a simple implementation of pure, map and flatMap methods. A non-trivial, bigger example is converted from Haskell to Scala: Reader is employed here to avoid passing the same argument around. Several Scala alternatives are presented and compared to the Reader solution. Read more