Fun (https://fun-lang.xyz)

What is Fun?

Fun is a highly strict programming language, but also highly simple. It looks like Python (My favorite language), but there are differences.

Influenced by Bash, C, Go, Lua, Python, and Rust (Most influences came from linked languages).

Fun is and will ever be 100% free under the terms of the Apache-2.0-License.

Idea

• Simplicity
• Consistency
• Joy in coding
• Fun!

Characteristics

• Dynamic and optionally statically typed
• Type safety
• Written in C (C11) and Fun
• Internal libs are written with no_camel_case even when written in Fun, except class Names
• Only a minimal function set is written in C, and most other core functions and libraries are implemented in Fun

The Fun Manifesto

Fun is a programming language built on a simple idea: Coding should be enjoyable, elegant, and consistent.

Philosophy

• Fun is Fun
  Programming should spark creativity, not frustration. Code in Fun feels light, playful, and rewarding.
• Fun Uses Nothing
  Minimalism is power. No unnecessary features, no endless syntax variations, no formatting debates. Just clean, uniform code.
• Indentation is Truth
  Two spaces, always. No tabs, no four-space wars. Code should look the same everywhere, from your laptop to /usr/bin/fun.
• One Way to Do It
  No clutter, no 15 ways of writing the same thing. Simplicity means clarity.
• Hackable by Nature
  Fun should be small and embeddable, like Lua. Easy to understand, extend, and tinker with — true to the hacker spirit.
• Beautiful Defaults
  A language that doesn’t need linters, formatters, or style guides. Beauty is built in.

The Community

Fun is not about being the fastest or the most feature-rich. It’s about sharing joy in coding. The community should be:

• Respectful
• Curious
• Creative

Like the name says: Fun Unites Nerds.

The Goal

A language that feels like home for developers who:

• Love minimal, elegant tools
• Believe consistency is freedom
• Want to write code that looks good and feels good

Fun may not change the world — but it will make programming a little more fun.

Documentation

Actually, there does not exist any documentation. In the examples/ directory should be an example of most Fun features.

Development

This section is a work in progress... Please excuse the lack of more information. There are daily updates here.

Requirements

A C compiler, a libc and Git.

FreeBSD

• CMake
• Clang

Linux

• CMake
• GCC (Clang should work here too, not tested!)

Windows

This requires Cygwin to be installed and configured. I will not cover this here.

• CMake
• Cygwin using GCC

Rules

• Every commit requires a version incremantion in CMakeLists.txt before committing
• Every commit message must contain the version at the end in the following format (1.2.3)
• Version numbering follows "Semantic Versioning 2.0.0"

Development systems

• GNU/Linux (Arch/Artix, Debian) using GCC and the GNU C library (glibc)
• GNU/Linux (Alpine) using GCC and the musl libc
• FreeBSD using Clang and the BSD libc
• Windows using Cygwin and GCC.

Other systems

• macOS, NetBSD, OpenBSD, etc. should fully work, but I don't know. I do not use these systems actually. You wanna try and report?

To Do

Everything... ;) No, a lot of stuff works already, but only a tiny set of functionality is available in the Fun programming language. It grows from day to day...

Build Fun

Linux/UNIX only covered here for now.

Clone repository:

git clone https://git.xw3.org/fun/fun.git

Change directory:

cd fun

Build:

cmake -S . -B build -DFUN_DEBUG=OFF -DFUN_WITH_PCSC=OFF -DFUN_WITH_REPL=ON
cmake --build build --target fun

That's it! For testing it, run:

FUN_LIB_DIR="$(pwd)/lib" ./build/fun ./demo.fun

To see what's going on, run:

FUN_LIB_DIR="$(pwd)/lib" ./build/fun --trace ./demo.fun

To switch into the REPL after an error, run:

FUN_LIB_DIR="$(pwd)/lib" ./build/fun --repl-on-error --trace ./demo.fun

Both --repl-on-error and --trace are optional but can always be combined. To get more debug information, you need to build Fun with -DFUN_DEBUG=ON.

To directly run the REPL, you have to run:

FUN_LIB_DIR="$(pwd)/lib" ./build/fun

But be sure to build Fun with -DFUN_WITH_REPL=ON.

Author

Johannes Findeisen - you@hanez.org