felix-lang/felix

---

felix-lang/felix.json

{
  "createdAt": "2010-03-02T07:11:15Z",
  "defaultBranch": "master",
  "description": "The Felix Programming Language",
  "fullName": "felix-lang/felix",
  "homepage": "",
  "language": "C",
  "name": "felix",
  "pushedAt": "2024-09-23T10:54:31Z",
  "stargazersCount": 814,
  "topics": [
    "c-plus-plus",
    "code-generator",
    "compiled",
    "compiler",
    "coroutine-framework",
    "coroutines",
    "functional-programming",
    "ocaml",
    "parametric-polymorphism",
    "performant",
    "platform-independent",
    "polymorphism",
    "programming",
    "programming-language",
    "scripting-language",
    "static-analysis",
    "type-classes"
  ],
  "updatedAt": "2025-11-20T02:53:45Z",
  "url": "https://github.com/felix-lang/felix"
}

Felix

An advanced, statically typed, high performance scripting language with native C++ embedding.

Features

Autobuilder

This file:

hello.flx

println$ "Hello World";

can be run directly:

flx hello.flx

It just works. No makefiles. No compiler switches. Automatic caching and dependency checking for Felix and C++. Uses a flx_pkgconfig database consisting of a directory of *.fpc files to specify and find libraries and header files based on in language abstract keys.

Hyperlight Performance

The aim is to run faster than C.

Underneath Felix generates highly optimised machine binaries which outperform most interpreters, bytecode compilers, virtual machines, and sometimes compiled languages including C and C++.

Felix is an aggressive inliner which performs whole program analysis and high level optimisations such as parallel assignment, self-tail call elimination.

Felix generates optimised C++ which is then compiled and optimised again by your system C++ compiler.

Compiler	Ack	Takfp
Felix/clang	3.71	6.23
Clang/C++	3.95	6.29
Felix/gcc	2.34	6.60
Gcc/C++	2.25	6.25
Ocaml	2.93	8.41

C and C++ embedding

Felix is a C++ code generator specifically designed so that all your favourite C and C++ libraries can be embedded with little or no glue logic:

// required header
header vector_h = '#include <vector>';

// C++11 for smart pointers
header memory_h = '#include <memory>'
  requires package "cplusplus_11"
;

// types
type vector[T] = "::std::shared_ptr<::std::vector<?1>>"
  requires vector_h, memory_h
;

type viterator[T] = "::std::vector<?1>::iterator"
  requires vector_h
;

// constructor
ctor[T] vector[T] : unit = "::std::make_shared<::std::vector<?1>>()";

// operations
proc push_back[T] : vector[T] * T =  "$1->push_back($2);";
proc push_back[T] (v: vector[T]) (elt:T) => push_back(v,elt);

fun stl_begin[T] : vector[T] -> viterator[T] = "$1->begin()";
fun deref[T] : viterator[T] -> T = "*$1";

// example use
var v = vector[int]!();
v.push_back 42;
println$ *v.stl_begin;

Getting Started

Prerequisites

• Python 3
• Ocaml 4.06.1 (only for source build)
• C++ compiler: g++, clang++, or msvc

Extras (can be installed later)

• SDL2 for graphics
• GNU GMP, GNU GSL

Build from Source

Linux

git clone https://github.com/felix-lang/felix.git
cd felix
. buildscript/linuxsetup.sh
make
sudo make install # optional!

OSX

git clone https://github.com/felix-lang/felix.git
cd felix
. buildscript/macosxsetup.sh
make
sudo make install # optional!

Building with Nix

On platforms supporting Nix, you can set up a build and runtime environment by running:

git clone https://github.com/felix-lang/felix.git
cd felix
nix-shell shell.nix
. buildscript/linuxsetup.sh
make

This will do an in place “install” of the Felix binaries. Note that this should work on OS X with Nix, but needs to be tested.

Windows

Follow the instructions on the Wiki.

Packages

Arch Linux

Use provided [PKGBUILD]!(./src/misc/PKGBUILD) to make an installable package. It is also available in the AUR repository

cd src/misc
makepkg
sudo pacman -U felix-VERSION.pkg.tar.xz

Tarballs

http://github.com/felix-lang/felix/releases

Build Status

Appveyor, Windows build: Travis, Linux build:

Links

Title	URL
Documentation Master	http://felix-documentation-master.readthedocs.io/en/latest/
Felix Tutorial	http://felix-tutorial.readthedocs.io/en/latest/
Installation and Tools Guide	http://felix-tools.readthedocs.io/en/latest/
Felix Language Reference Manual	http://felix.readthedocs.io/en/latest/
Felix Library Packages	http://felix-library-packages.readthedocs.io/en/latest/
Articles on Modern Computing	http://modern-computing.readthedocs.io/en/latest/
Felix Home Page	http://felix-lang.github.io/felix
Felix Wiki	https://github.com/felix-lang/felix/wiki
Git Repository	https://github.com/felix-lang/felix
Binary Download	http://github.com/felix-lang/felix/releases

Mailing List

mailto:felixpl@googlegroups.com

Licence

Felix is Free For Any Use (FFAU)/Public Domain.