glossopoeia / boba

A general purpose statically-typed concatenative programming language.

Boba - A Structured Concatenative Language

Boba is an early-stage, general purpose concatenative programming language.

Key features include:

1. Expressive, mostly implicit static types and kinds
2. Language-incorporated unit and property tests + runners
3. Algebraic effects via scoped effect handlers
4. Algebraic data types and pattern matching on constructors
5. Compile-time resolved function overloading
6. Structurally typed tuples, records and variants
7. Byte-code VM-in-Go backend with straight-forward first-order FFI access
8. Familiar looping, branching, and variable definition syntax constructs

Hailstone Example

func is-even n = n 2 rem-i32 0 eq-i32

about :
/// The `hailstone` function is sometimes named that because of how the values
/// 'bounce' up and down (like hail in a storm cloud) as the sequence computes.
rec func hailstone n =
    switch {
        | n 1 eq-i32 => []
        | n is-even  => n 2 div-i32 hailstone
        | else       => 3 n mul-i32 inc-i32 hailstone
    }
    n cons-list

test hailstone-1? = 1 hailstone is [1]
test hailstone-2? = 2 hailstone is [1, 2]
test hailstone-3? = 3 hailstone is [1, 2, 4, 8, 16, 5, 10, 3]
test hailstone-6? = 6 hailstone is [1, 2, 4, 8, 16, 5, 10, 3, 6]

export { hailstone }

See the test/ folder for many more examples of Boba syntactic and semantic features.

Building from source

The Boba compiler is currently implemented in F#. Recommended to have both .NET 6 and Go language version 1.18 installed on the system before building. This repository is Gitpod compatible and will automatically create a container capable of building and running the compiler.

Example build-and-run command:

dotnet run --project Boba.Compiler compile test/while-expr

This will build the compiler, then compile the test/while-expr.boba file in the tests directory into an executable and then run it.

To use Boba's inline testing features, simply replace compile with test:

dotnet run --project Boba.Compiler test test/ackermann

This will run all the tests present in the test/ackermann.boba file and report on their success/failure.

To run a test or program without the current runtime debug trace, include a release flag:

dotnet run --project Boba.Compiler test test/hailstone release

Installation

Installers and binary packages are not yet available while the compiler CLI further stabilizes.

License

Boba is available and distributed under the terms of the MIT license. See LICENSE for details.

Roadmap

In no particular order, and missing some potential work that may take priority:

• Community feature: Better showcase examples
• Ecosystem feature: Flesh-out primitives library further
• Codegen feature: Compile some Boba functions to Go rather than byte-code