fifthlang

CI runs on Linux, macOS, and Windows for pushes/PRs to master, plus a nightly schedule. TRX test results are uploaded as workflow artifacts.

Coverage: CI collects cross-platform coverage via XPlat Code Coverage; HTML and Cobertura reports are uploaded as artifacts per-OS.

A compiler and language tooling for the Fifth programming language.

👉 Latest Announcement: Graph Assertion Blocks

Quickstart

If you wish to work on 5th from Neovim, and you have Nix installed, you can create a development shell session like this:

$ nix develop

# or . . 

$ nix develop -c fish

alias x as <http://example.com/blah#>;

// Declare a default SPARQL store (canonical syntax)
home : store = sparql_store(<http://localhost:8080/graphdb>);

class Person in <x:>
{
    dob : datetime ;
    age : int ;
}

calculate_age(val : datetime): TimeSpan
{
    return datetime.Now() - val;
}

foo(a : int, n : string): void
{
    eric : Person = new Person();
    ericKnowledge : graph in <x:people> = <{
        d: datetime = datetime(1926, 5, 14);
        eric.dob = d;
        eric.age = calculate_age(d);
    }>;
    home += ericKnowledge;
}

Prerequisites

• .NET SDK 8.0+
• Java 17+ (ANTLR toolchain; 11 may work but 17 is recommended)
• ilasm on PATH or configured via env vars (see src/compiler/README.md)

Build

# From repo root
 dotnet build fifthlang.sln
 # Or with just (runs restore + build fast)
 just build-all (or: make build-all)

MSBuild Project Support (.5thproj)

Fifth projects can be integrated into .NET solutions using the .5thproj MSBuild project type provided by Fifth.Sdk.

Example .5thproj

<Project Sdk="Fifth.Sdk">
  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net8.0</TargetFramework>
    <AssemblyName>MyFifthApp</AssemblyName>
  </PropertyGroup>
</Project>

Building .5thproj

dotnet build MyProject.5thproj
# Or add to a solution
dotnet sln add MyProject.5thproj
dotnet build MySolution.sln

For more details, see src/Fifth.Sdk/README.md.

Tests

# List and run tests for the whole solution
 dotnet test fifthlang.sln --list-tests
 dotnet test fifthlang.sln

# Run a specific test project
 dotnet test test/ast-tests/ast_tests.csproj
 dotnet test test/runtime-integration-tests/runtime-integration-tests.csproj

## Coverage
- Local run with Cobertura output (aligned with CI):
```fish
dotnet test fifthlang.sln --no-build --collect "XPlat Code Coverage" --logger "trx;LogFileName=results.trx" --settings fifth.runsettings
# Locate outputs
find test -type f -name '*.trx' | sed -n '1,20p'
find . -type f -name 'coverage.cobertura.xml' | sed -n '1,20p'

• Optional HTML report (requires ReportGenerator):

dotnet tool install -g dotnet-reportgenerator-globaltool
set -gx PATH $HOME/.dotnet/tools $PATH
reportgenerator -reports:**/coverage.cobertura.xml -targetdir:CoverageReport -reporttypes:Html;TextSummary
open CoverageReport/index.html 2>/dev/null; and echo "Opened report in browser"

## VS Code
- Recommended extensions are defined in `.vscode/extensions.json`.
- Dev Kit Testing UI with TUnit:
  - See `docs/vscode-devkit-tests.md` for setup and discovery steps.

## Knowledge Graphs (Overview)
- Canonical store declaration: `name : store = sparql_store(<iri>);` or `store default = sparql_store(<iri>);`
- Graph assertion blocks: `<{ ... }>`
  - Expression-form yields an `IGraph` value.
  - Statement-form requires a default store and saves the graph to it.
- Built-ins are provided via `Fifth.System.KG` (e.g., `CreateGraph`, `CreateUri`, `CreateLiteral`, `CreateTriple`, `Assert`, `SaveGraph`).
- Supported object literals include strings, booleans, chars, all signed/unsigned integers, float, double, and precise `decimal`.

## Repo layout
- `src/` – language, parser, code generator, compiler
- `test/` – unit and integration tests
- `docs/` – guides and notes (Dev Kit testing setup, etc.)

## License
See `src/LICENSE`.