acieroid / flix

The Flix Programming Language

Flix is a statically typed functional- and logic programming language inspired by Scala, OCaml, F#, Haskell, and Datalog. The syntax of Flix resembles Scala and Datalog. The type system supports local type inference and is based on Hindley-Milner. Flix runs on the Java Virtual Machine and compiles directly to JVM bytecode.

See the official Flix website for more information about Flix.

Example

///
/// The expressions of the lambda calculus are: variables, lambda abstractions, and applications.
///
enum Expression {
    // A variable expression. A variable is represented by an integer.
    case Var(Int),

    // A lambda abstraction expression. A variable is represented by an integer.
    case Abs(Int, Expression),

    // A function application expression.
    case App(Expression, Expression)
}

///
/// Performs alpha conversion by introducing fresh variables for all variables in the given expression `e0`.
///
def alpha(e0: Expression, m: Map[Int, Int]): Expression = match e0 with {
    case Var(x) =>
        // Check if we need to rename the variable.
        match Map.get(x, m) with {
            case None    => Var(x)
            case Some(y) => Var(y)
        }
    case Abs(x, e) =>
        // Generate a fresh variable name for `x`.
        let y = freshVar();
        Abs(y, alpha(e, Map.insert(x, y, m)))

    case App(e1, e2) =>
        // Recursively perform alpha conversion on each expression.
        App(alpha(e1, m), alpha(e2, m))
}

License

Flix is available under the Apache 2.0 license.

Sponsors

We kindly thank EJ Technologies for providing us with JProfiler and JetBrains for providing us with IntelliJ IDEA.