#moonbit-libyue

#Platform support

• Ubuntu 24.04 Xfce
• Ubuntu 24.04 GNOME
• Ubuntu 24.04 KDE
• Deepin 25
• Windows 10 / 11
• Mac (no device to test)

#Yue

#Three ways to build UI

#Demos

#Modern — themed component library

#Classic — native widgets

#Usage

#Quick start

#Ubuntu 24.04

sudo apt install build-essential cmake pkg-config \
  libgtk-3-dev libpango1.0-dev libfontconfig1-dev libx11-dev \
  libwebkit2gtk-4.1-dev

moon run examples/hello

#Windows (10/11, x64)

1. Install the MoonBit toolchain:

irm https://cli.moonbitlang.com/install/powershell.ps1 | iex

2. Install CMake and the MSVC C++ toolchain:

winget install Kitware.CMake
winget install Microsoft.VisualStudio.2022.BuildTools -e --override "--quiet --wait --norestart --add Microsoft.VisualStudio.Workload.VCTools --includeRecommended"

3. Add the ATL component:

Start-Process -FilePath 'C:\Program Files (x86)\Microsoft Visual Studio\Installer\setup.exe' -ArgumentList 'modify','--installPath','"C:\Program Files (x86)\Microsoft Visual Studio\2022\BuildTools"','--add','Microsoft.VisualStudio.Component.VC.ATL','--quiet','--norestart' -Verb RunAs -Wait

4. Build and run. On Windows moon looks for cl on PATH when compiling native code, so run it from the "x64 Native Tools Command Prompt for VS 2022", or call vcvars64.bat first:

call "C:\Program Files (x86)\Microsoft Visual Studio\2022\BuildTools\VC\Auxiliary\Build\vcvars64.bat"
python3 scripts\prepare.py
moon run examples/hello

#Use as a dependency

moon add NoahLiu/moonbit-libyue
moon run src

#Declarative UI

fn main {
  if !@yue.initialize() {
    return
  }
  let window = @yue.mount_window(
    [
      @yue.label("Hello, MoonBit + libyue!", style=[("margin", 20.0)]),
      @yue.button("Quit", on_click=fn() { @yue.quit() }),
    ],
    title="Hello",
    size=Some((420.0, 160.0)),
    center=true,
    on_close=fn(_w) { @yue.quit() },
  )
  window.activate()
  @yue.run()
}

let clicks : @yue.Store[Int] = @yue.Store::new(0)
let window = @yue.mount_window(
  [
    @yue.vbox(
      [
        @yue.button("Click me", on_click=fn() { clicks.update(fn(n) { n + 1 }) }),
        @yue.bind_label(clicks, fn(n) { "Clicked \{n} times" }),
      ],
      style=[("padding", 24.0)],
    ),
  ],
  title="Counter",
  size=Some((320.0, 160.0)),
  center=true,
  on_close=fn(_w) { @yue.quit() },
)

#Documentation

#Development

• Build & test: moon check && moon test
• Adding a widget: mechanical translation in shim/yue_mbt.cpp → declaration in shim/include/yue_mbt.h → extern "c" in yue/ffi.mbt → type & methods in a new yue/*.mbt (FFI conventions in .agents/skills/moonbit-c-binding/).
• Current binding surface: ~320 ABI functions (324 extern "c" declarations in yue/ffi.mbt).
• Real-world pitfalls and platform lessons go to docs/adaptation.md; usage docs and code comments stay content-only.
• After shim/vendor changes, force a relink: moon clean or delete the executable — see docs/relink.md.

#References

• libyue documentation: https://libyue.com/docs/latest/cpp/guides/getting_started.html
• Lua bindings: github.com/yue/yue
• MoonBit skill library: .agents/skills/ (moonbit-c-binding, make-moonbit-c-bindings)
• AI collaboration rules: AGENTS.md
• Platform adaptation experience: docs/adaptation.md