In this article, we explain how to implement a Language Server Protocol server to decouple code presentation from language logic, using Metals and Scala. It walks through adding a simple document highlight feature. 
Kotlin lacks Java’s package-private visibility, exposing everything by default unless explicitly marked, which can bloat APIs and hinder encapsulation. The author praises Java’s manifest-based modular exports for making visibility decisions more conscious and centralized.
VirtusLab compares object‑oriented and functional programming through the Expression Problem, showing how each paradigm handles extensibility differently. The article highlights how FP easily adds new operations, while OOP easily adds new data forms.
A general abstraction extends functions into composable building blocks, enabling the expression of business logic as data flows. This shift transforms side‑effecting, exception‑ridden code into clean, purely functional pipelines.
