Flix – A powerful effect-oriented programming language

I am deeply impressed by the depth and breadth of this language. Algebraic data types, logic programming, mutability, all there from the get go. Another aspect that I love from their comparison table is that a single executable is both the package manager, LSP and the compiler. As I understand, the language server for Haskell has/had to do a lot of dances and re implement things from ghc as a dance between the particular ghc version and your cabal file…

The website is infrequently updated, so let me provide some information about what we are currently working on: - We are trying to make the entire compiler resilient (error-tolerant), incremental, and parallel. We have managed to make every single compiler phase (of which there are 28) parallel. This has already led to significant speed-ups. We are now trying to increase the degree of parallelism within each phase. We are also working on error resilience to provide LSP support no matter…

The Datalog support is a very interesting feature for such a fully-featured language. From the home page: def reachable(g: List[(String, Int32, String)], minSpeed: Int32): List[(String, String)] = let facts = project g into Road; let rules = #{ Path(x, y) :- Road(x, maxSpeed, y), if maxSpeed >= minSpeed. Path(x, z) :- Path(x, y), Road(y, maxSpeed, z), if maxSpeed >= minSpeed. }; query facts, rules select (src, dst) from Path(src, dst) |> Foldable.toList Composing datalog natively like any other type –…

I'm curious about the emphasis on fixpoints and lattices. These are two quite simple concepts often overlooked in CS and emphasized even less in programming languages. Lattices are natural to CS in that any time you have an order or even any binary relation, that imposes some structure on your values, and knowing the/solving for unique fixpoints (considering also continuity conditions) can be powerful, for instance the most general type of an expression, the "final" result of a recursive definition…