The previous article argued that compilers could check more than they currently do — and that the agentic coding era makes this urgent. The articles that follow demonstrate specific features in Ruuk, a language designed around that idea. But Ruuk's syntax is based on F#, and if you've never seen an ML-family language, the examples will be harder to follow than they need to be.
This article is a warp-speed tour of F# syntax — just enough to read the Ruuk code in the rest of the series. If you've written C#, Java, or TypeScript, nothing here is conceptually alien. The ideas have direct parallels; the notation is just different. And to keep things interesting, we'll model our examples around the operational systems of a certain starship.
Why Fsharp
The choice of F# as Ruuk's syntactic foundation wasn't personal preference. Before I'd decided on paradigm or syntax style, I studied how programmers actually read code — drawing on cognitive linguistics research. Two findings shaped the design. First, people tend to read code the same way they read prose: linearly, left to right, top to bottom. Nested function calls like toUpper(trim(getName(user))) force inside-out reading — you start at the innermost call and work outward. Fluent method chaining — user.getName().trim().toUpper() — solves the reading-order problem, but it ties each step to a method defined on the preceding type. A pipeline like user |> getName |> trim |> toUpper reads in the same order things happen, and the functions are standalone — they compose freely without needing to live on a class. ML-family languages build around this style, and that made them a natural place to start.
