Update syntax

.gitignore

@@ -1,3 +1,6 @@
+# test program
+ctest
+
 # Byte-compiled / optimized / DLL files
 __pycache__/
 *.py[cod]

Makefile

@@ -1,13 +1,29 @@
-all: lib test
+.PHONY: all lib test memcheck clean
 
-lib:
-	rustc points.rs 
+OS := $(shell uname)
 
-test:
-	gcc -o test test.c 
+ifeq ($(OS),Darwin)
+    LIB = libpoints.dylib
+else
+    LIB = libpoints.so
+endif
 
-memcheck:
-	valgrind --tool=memcheck  --leak-check=full  ./test
+all: $(LIB) test
+
+lib: $(LIB)
+
+$(LIB): points.rs
+	rustc points.rs
+
+ctest: test.c $(LIB)
+	gcc -o ctest test.c -g -ldl
+
+test: $(LIB) ctest
+	./ctest
+	python load_libpoint.py
+
+memcheck: ctest
+	valgrind --tool=memcheck --leak-check=full ./ctest
 
 clean:
-	rm  -f libpoints.dylib libpoints.so test
+	rm -f $(LIB) ctest

load_libpoint.py

@@ -1,35 +1,41 @@
+#!/usr/bin/env python
 """
 Small example how to load the shared library created with rust in python
-by Lutz Paelike 
+by Lutz Paelike
 """
+# pylint: disable=invalid-name
+
+from __future__ import print_function
 
 import sys
 
 import cffi
-ffi=cffi.FFI()
+FFI = cffi.FFI()
+FFI.cdef("""
+    struct Point{ int x,y; };
 
-ffi.cdef ("""
-    struct Point { int x,y; }; 
-
     struct Point* make_point(int, int);
-    void free_point(struct  Point*);
+    void free_point(struct Point*);
 
-    double get_distance( struct  Point*, struct  Point*);
+    double get_distance(struct Point*, struct Point*);
     """)
 
 if sys.platform == "darwin":
-    libname = "libpoints.dylib"
+    LIBNAME = "./libpoints.dylib"
 else:
-    libname = "libpoints.so"
-
-lib = ffi.dlopen(libname)
+    LIBNAME = "./libpoints.so"
 
+LIB = FFI.dlopen(LIBNAME)
 
-a = lib.make_point(20,20)
-b = lib.make_point(10,10)
+def main():
+    """Show use of Rust structs and functions"""
+    a = LIB.make_point(20, 20)
+    b = LIB.make_point(10, 10)
 
-print "distance : ",lib.get_distance(a,b)
+    print("distance: {:.8g}".format(LIB.get_distance(a, b)))
 
-lib.free_point(a)
-lib.free_point(b)
+    LIB.free_point(a)
+    LIB.free_point(b)
 
+if __name__ == '__main__':
+    main()

points.rs

@@ -1,34 +1,36 @@
 #![crate_type = "dylib"]
 #![crate_name = "points"]
+#![allow(unstable)]
 
 // Based on http://blog.skylight.io/bending-the-curve-writing-safe-fast-native-gems-with-rust/
 // by Yehuda Katz
 
 
-use std::num::pow;
+use std::num::{Int, Float};
 
-pub struct Point { x: int, y: int }  
-struct Line  { p1: Point, p2: Point }
+#[derive(Copy)]
+pub struct Point { x: isize, y: isize }
+struct Line { p1: Point, p2: Point }
 
-impl Line {  
+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()
+    ((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 }
+pub extern "C" fn make_point(x: isize, y: isize) -> Box<Point> {
+    Box::new(Point{x: x, y: y})
 }
 
 #[no_mangle]
-pub extern "C" fn free_point(p: Box<Point>)  {  
+pub extern "C" fn free_point(p: Box<Point>)  {
    drop(p);
 }
 
 #[no_mangle]
-pub extern "C" fn get_distance(p1: &Point, p2: &Point) -> f64 {  
-    Line { p1: *p1, p2: *p2 }.length()
-}
+pub extern "C" fn get_distance(p1: Box<Point>, p2: Box<Point>) -> f64 {
+    Line{p1: *p1, p2: *p2 }.length()
+}

test.c

@@ -1,25 +1,28 @@
 #include <dlfcn.h>
 #include <stdio.h>
 
+#ifdef __APPLE__
+#define LIBEXT "dylib"
+#else
+#define LIBEXT "so"
+#endif
 
-
-typedef struct Point* (_make_point)( int x, int y);
+typedef struct Point* (_make_point)(int x, int y);
 typedef struct Point* (_free_point)(struct Point* p);
 
-typedef double (_get_distance)( struct Point* a, struct Point* b);
-
+typedef double (_get_distance)(struct Point* a, struct Point* b);
 
 int main(int argc, char *argv[]) {
-    void *myso = dlopen("./libpoints.dylib", RTLD_NOW);
-    
+    void *myso = dlopen("./libpoints." LIBEXT, RTLD_NOW);
+
     _make_point *make_point = dlsym(myso, "make_point");
     _free_point *free_point = dlsym(myso, "free_point");
 
     _get_distance *get_distance = dlsym(myso, "get_distance");
 
-
     struct Point*  a = make_point(10,10);
     struct Point*  b = make_point(20,20);
+
     double d = get_distance(a,b);
     printf("distance: %f\n", d);
 
@@ -29,5 +32,4 @@ int main(int argc, char *argv[]) {
     dlclose(myso);
 
     return 0;
-
-}
+}