<img src="https://upload.wikimedia.org/wikipedia/commons/8/80/Che_Guevara_-_Guerrillero_Heroico_by_Alberto_Korda.jpg" alt="Che Guevara" style="height:100px;"/> ## Wrapping C++ and Python libraries for JavaScript ### The guerilla-slides-react-native-connection-2025 <img src="https://upload.wikimedia.org/wikipedia/commons/2/2a/La_Guerra_de_Guerrillas_%28edición_de_1961%29.png" alt="Guerilla Warfare" style="height:200px;"/>

<img src="https://raw.githubusercontent.com/mmomtchev/guerilla-slides/refs/heads/main/C%2B%2B_in_Javascript.png" alt="C++ in JavaScript" style="height:70vh;"/>

JavaScript has become the new universal language - and it happened almost by accident * because of all the R&D that went into highly efficient interpreters * because it allows to share backend and frontend code

JavaScript is notoriously difficult to interoperate with other languages. So, for the last two decades, people have been trying to rewrite all existing software in JavaScript - there was simply no other way around it. ## But is this actually feasible?

I have authored or co-authored the bindings of four major C++ libraries for JavaScript: * `GDAL` - only Node.js * `ImageMagick` - both browser and Node.js, the first SWIG JSE project, about 2 man-months * `ffmpeg` - only Node.js - the first `nobind17` project, * `PROJ` - both browser and Node.js Rewriting these in JavaScript is a monumental task.

Automatically generating wrappers for high-level interpreted languages by compiling the C/C++ header files is a solved problem: it is called # SWIG and it exists since the 1990s. However until 2024, JavaScript support was very rudimentary, covered only Node.js and wasn't really updated since the Node.js 0.x era.

## The Holy Grail of JavaScript/C++ interoperability ```shell git clone https://github.com/ImageMagick/ImageMagick abracadabra ImageMagick ``` then ```js import { Magick } from '@abracadabra/ImageMagick'; ``` And it works both in Node.js and in the browser!

This has been achieved for Python libraries! It is called `pymport`: ``` npm install pymport npx pympip3 install numpy ``` then ```js const { pymport, proxify } = require('pymport'); const np = proxify(pymport('numpy')); const a = np.arange(15).reshape(3, 5); const b = np.ones([2, 3], { dtype: np.int16 }); ```

### ...For C++ we are not there yet *but at least we are going in the right direction* Today, there are two choices: ### SWIG JavaScript Evolution - Very powerful, supports both Node.js and WASM but has a very steep learning curve ### `nobind17` - `pybind11`-like - Very simple to use, does not require any special knowledge beyond C++ but it has its limits and supports only C++ for Node.js

* `GDAL`, my first project, as a co-author, was completely hand-written bindings - it costed more than 1 man-year * `ImageMagick`, the first SWIG JSE project, took about 1 man-month, 400k lines of C++ code generated from 800 lines of SWIG JSE code * `ffmpeg`, the first `nobind17` project - about 2 man-weeks to get it to mostly working status * `PROJ`, the second SWIG JSE project - about 2 man-weeks The cost savings are tremendous!

* The bindings support both synchronous and asynchronous calls - both in Node.js and in the browser *(async in the browser requires COOP/COEP)* * `import`ing is completely automatic - just as if this was JavaScript - the bundler picks up either the browser WASM version or the Node.js native version * The TypeScript types are autogenerated * The C++ STL is replaced by methods that have native JavaScript feel

Interfacing the two languages is not enough! End-users expect `npm` packages - which must be so seamless, that the developer does not need to know about the C++ *time to ditch `node-gyp`* ## Enter the `hadron` build system

# `hadron` * `meson`-based build system which is compatible with CMake and autotools * `xpm`-orchestrator for seamless integration with `conan` and a built-in C++ compiler in an `npm` package ImageMagick comes prebuilt with more than 20 libraries - on Linux, macOS and Windows, and WASM - and it can rebuild itself upon installation, pulling the libraries from `conan` and using its own C++ compiler!

I am unemployed and homeless software engineer living on the street on social welfare and working full-time on open source in my van using solar panels. I am currently the target of a huge extortion, that involves many of the largest IT companies in the world - including Google, X, Microsoft and Facebook - as well as the French police - about a series of irregular criminal and civil cases with sexual motivation. I chose to live on the street with almost no money instead of accepting a job in a criminal company willing to help cover up this affair since I consider this to be a more meaningful use of my life.

* SWIG JSE - https://github.com/mmomtchev/swig * `nobind17`- https://www.npmjs.com/package/nobind17 * `hadron` - https://github.com/mmomtchev/hadron * `magickwand.js` - https://www.npmjs.com/package/magickwand.js * `gdal-async` - https://www.npmjs.com/package/gdal-async * `node-ffmpeg` - https://www.npmjs.com/package/@mmomtchev/ffmpeg * `proj.js` - https://www.npmjs.com/package/proj.js

As a side note, you may have noticed that my flyers reference the dotJS 2024 conference. Alas, the flyers for this conference were conveniently *"lost"* by DPD last week. This event was accompanied by a number of notifications that I received on X by fake DPD accounts and X themselves. It seems that the people behind the extortion had promised to everyone who helped them to drive me away from the React Native community in 2022-2023, to stop this presentation.

# For great justice! <img src="https://i.kym-cdn.com/photos/images/newsfeed/001/553/629/3c9.jpg" alt="All your base are belong to us" style="height:500px;"/>