gistfile1.sh

rustc points.rs --crate-type=dylib

npm install

node test.js

package.json

{
  "name": "rusty",
  "version": "0.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "ffi": "^1.2.7",
    "node-ffi": "^0.5.7"
  }
}

points.rs

use std::num::pow;

pub struct Point { x: int, y: int }  
struct Line  { p1: Point, p2: Point }



impl Line {  
  pub fn length(&self) -> f64 {
    let xdiff = self.p1.x - self.p2.x;
    let ydiff = self.p1.y - self.p2.y;
    ((pow(xdiff, 2) + pow(ydiff, 2)) as f64).sqrt()
  }
}


#[no_mangle]
pub extern "C" fn get_distance(p1: &Point, p2: &Point) -> f64 {  
    Line { p1: *p1, p2: *p2 }.length()
}

#[no_mangle]
pub extern "C" fn make_point(x: int, y: int) -> Box<Point> {  
    box Point { x: x, y: y }
}

test.js

var ffi = require('ffi');

var RustPoint = ffi.Library('./libpoints', {
  'make_point': [ 'pointer', [ 'int', 'int'] ],
  'get_distance': [ 'double', [ 'pointer', 'pointer'] ]
});


var p1 = RustPoint.make_point(10, 10);
var p2 = RustPoint.make_point(20, 20);

console.log(RustPoint.get_distance(p1, p2));