points

points.rb

require "fiddle"
require "fiddle/import"

module RustPoint
  extend Fiddle::Importer

  dlload "./libpoints.dylib"

  extern "Point* make_point(int, int)"
  extern "double get_distance(Point*, Point*)"
end

points.rs

use std::num::Int;
use std::num::Float;

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;
    ((xdiff.pow(2) + ydiff.pow(2)) as f64).sqrt()
  }
}

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

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