# Fun ([https://fun-lang.xyz](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](https://www.gnu.org/software/bash/)**, **[C](https://en.wikipedia.org/wiki/The_C_Programming_Language)**, Go, **[Lua](https://www.lua.org/)**, **[Python](https://www.python.org/)**, 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](https://opensource.org/license/apache-2-0).
## Idea
- Simplicity
- Consistency
- Joy in coding
- Fun!
### Extras
- [cURL](https://curl.se/) support builtin using [libcurl](https://curl.se/libcurl/) (optional) ☑
- [JSON](https://www.json.org/) support builtin using [json-c](https://github.com/json-c/json-c) (optional) ☑
- [PCSC](https://pcscworkgroup.com/) smart card support builtin using [PCSC lite](https://pcsclite.apdu.fr/) (optional) ☑
- [PCRE2](https://pcre2project.github.io/pcre2/) support builtin for Perl-Compatible Regular Expressions (optional) ☑
- [SQLite](https://sqlite.org/) support builtin (optional) ☐
- [Tk](https://www.tcl-lang.org/) support builtin for GUI application development (optional) ☐
☑ = Done / ☐ = Planned or in progress.
## Characteristics
- Dynamic and optionally statically typed
- Type safety
- Written in C (C99) 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.
Please visit the [Fun Community Page](https://fun-lang.xyz/community/) to get in touch.
## 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
I am writing documentation only actually, but this is work in progress, since debugging and bug fixing includes this task.
Current documentation is only found in the [Fun Handbook](https://git.xw3.org/fun/fun/src/branch/main/docs/handbook.md).
In the [examples/](https://git.xw3.org/fun/fun/src/branch/main/examples) directory should be an example of most Fun features.
A complete API documentation will follow.
## Development
This section is a work in progress... Please excuse the lack of more information. There are daily updates here.
### Rules
- Every commit message must contain the version at the end in the following format (1.2.3)
- Every commit requires a version incrementation in CMakeLists.txt before committing. Documentation updates do not increment the version but must contain the current version in each commit message.
- Version numbering follows "[Semantic Versioning 2.0.0](https://semver.org/spec/v2.0.0.html)"
### Development systems
- [GNU](https://gnu.org/)/[Linux](https://kernel.org/) ([Arch](https://archlinux.org/)/[Artix](https://artixlinux.org/), [Debian](https://www.debian.org/)) using [GCC](https://gcc.gnu.org/) and the [GNU C library](https://www.gnu.org/software/libc/) ([glibc](https://en.wikipedia.org/wiki/Glibc))
- GNU/Linux ([Alpine](https://alpinelinux.org/)) using GCC and the [musl libc](https://musl.libc.org/)
- [FreeBSD](https://www.freebsd.org/) using [Clang](https://clang.llvm.org/) and the [BSD libc](https://en.wikipedia.org/wiki/C_standard_library#BSD_libc)
- [Windows](https://en.wikipedia.org/wiki/Microsoft_Windows) using [Cygwin](https://www.cygwin.com/) and GCC.
### Other systems
- [macOS](https://en.wikipedia.org/wiki/MacOS), [NetBSD](https://netbsd.org/), [OpenBSD](https://www.openbsd.org/), 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:
```bash
git clone https://git.xw3.org/fun/fun.git
```
Change directory:
```bash
cd fun
```
Build:
```bash
# Note: Every -D flag must be of the form NAME=VALUE (e.g., -DFUN_WITH_REPL=ON)
cmake -S . -B build -DFUN_DEBUG=OFF -DFUN_WITH_PCSC=OFF -DFUN_WITH_REPL=ON -DFUN_WITH_JSON=ON
cmake --build build --target fun
```
CMake options you can toggle (all require NAME=VALUE):
- FUN_DEBUG=ON|OFF — verbose debug logging in the VM (default OFF)
- FUN_WITH_CURL=ON|OFF — enable CURL support using libcurl (default OFF)
- FUN_WITH_JSON=ON|OFF — enable JSON support via json-c (default OFF)
- FUN_WITH_PCRE2=ON|OFF — enable PCRE2 Perl-Compatible Regular Expressions support (default OFF)
- FUN_WITH_PCSC=ON|OFF — enable PCSC smart card support (default OFF)
- FUN_WITH_REPL=ON|OFF — enable the interactive REPL (default ON)
That's it! For testing it, run:
```bash
FUN_LIB_DIR="$(pwd)/lib" ./build/fun ./demo.fun
```
To see what's going on, run:
```bash
FUN_LIB_DIR="$(pwd)/lib" ./build/fun --trace ./demo.fun
```
To switch into the REPL after an error, run:
```bash
FUN_LIB_DIR="$(pwd)/lib" ./build/fun --repl-on-error --trace ./demo.fun
```
Both --repl-on-error and --trace are optional but can always be combined. To get
more debug information, you need to build Fun with -DFUN_DEBUG=ON.
To directly run the REPL, you have to run:
```bash
FUN_LIB_DIR="$(pwd)/lib" ./build/fun
```
But be sure to build Fun with -DFUN_WITH_REPL=ON.
Tip: If you saw an error like this when configuring with CMake:
CMake Error: Parse error in command line argument: FUN_WITH_JSON
Should be: VAR:type=value
it means a -D flag was passed without a value. Always specify options as -DNAME=VALUE, for example:
-DFUN_WITH_JSON=ON
## Author
Johannes Findeisen