Skrylar

i686-unknown-linux-gnu
i686-unknown-linux-gnu/rt
i686-unknown-linux-gnu/rt/stage1
i686-unknown-linux-gnu/rt/stage1/sundown
i686-unknown-linux-gnu/rt/stage1/sundown/src
i686-unknown-linux-gnu/rt/stage1/sundown/html
i686-unknown-linux-gnu/rt/stage1/sync
i686-unknown-linux-gnu/rt/stage1/isaac
i686-unknown-linux-gnu/rt/stage1/test
i686-unknown-linux-gnu/rt/stage1/arch

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Binding Rust to C

This document is a work in progress, and is primarily concerned with getting Rust code able to talk with C code. What we cover here is writing 'bindings', we will cover 'wrapping' up the bindings and providing an elegant interface in the next document.

Extern blocks

The most basic building block of interfacing Rust with C is the extern block, which is necessary for telling Rust that the C functions you wish to use actually exist.

Example.

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Tips for Rust: Result Types

Expecting certain outcomes from a Result

Why is it that there is an Option.expect(M), but no Result.expect(M)?

I opened a pull request [pr] which put this in, and it turns out the reason there is no expect function is because you are intended to use composition:

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extern mod sdl;

use std::rc::Rc;

struct Foof;

impl sdl::MouseDelegate for Foof {
	fn mouse_did_move(_info: &sdl::MouseMotionEventInfo)  {
		println!("Mouse position: {}x{}", _info.x(), _info.y())

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	#[inline]
	unsafe fn with_window_event_db(_in: &CommonEventInfo, block: |&mut DelegateBoard|) {
		let event : &MouseMotionEventInfo = cast::transmute(_in);
		EventPump::with_window_db(event.window_id(), block)
	}

	unsafe fn with_window_db(id: u32, block: |&mut DelegateBoard|) {
		let win = ffi::SDL_GetWindowFromID(id);
		if win.is_not_null() {
			let dbp = ffi::SDL_GetWindowData(win, bytes!("rust_cb", 0).as_ptr() as *i8);

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fn main() {
	let mut sentry = sdl::init(sdl::init::Video).unwrap();

	let win = sentry.new_window("Foof wob", 32, 32, 800, 600, 0).unwrap();
	let mut x = win.borrow_mut();

	/* does this work for putting the trait types in? */
	sentry.set_application_delegate(&Foof as &sdl::ApplicationDelegate);
	x.get().set_mouse_delegate(&Foof as &sdl::MouseDelegate);

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pub trait ApplicationDelegate {
    fn application_did_quit(&mut self, _timestamp: u32) {}
}

pub trait MouseDelegate {
	fn mouse_did_move(&mut self, _info: &MouseMotionEventInfo)  {}
	fn mouse_did_click(&mut self, _info: &MouseButtonEventInfo) {}
	fn mouse_did_scroll(&mut self, _info: &MouseWheelEventInfo) {}
}

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#[crate_id = "mu1"];
#[crate_type = "bin"];

use std::cast::transmute;
use std::cell::RefCell;
use std::libc::size_t;
use std::rc::{Rc, Weak};

static ErrAlreadyParented: &'static str = "Morph already has a parent.";

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import unittest
  
proc doThings(spuds: var int): int =
  spuds = 24
  return 99

suite "broken":
  test "count the spuds":
    var spuds = 0
    check doThings(spuds) == 99

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import
  rectangle

type 
  MaxRectPacker* [T] = object
    initialWidth, initialHeight: T
    freeGeometry: seq[Rectangle[T]]

proc TryGet* [T](self: var MaxRectPacker[T];