Standardise Mzscheme simple example

Changes so that it works the same as other language modules

Examples/mzscheme/simple/README

@@ -1 +0,0 @@
-Simple example from users manual.

Examples/mzscheme/simple/example.c

@@ -1,24 +1,18 @@
-/* Simple example from documentation */
 /* File : example.c */
 
-#include <time.h>
+/* A global variable */
+double Foo = 3.0;
 
-double My_variable = 3.0;
-
-/* Compute factorial of n */
-int fact(int n) {
-  if (n <= 1) return 1;
-  else return n*fact(n-1);
-}
-
-/* Compute n mod m */
-int my_mod(int n, int m) {
-  return (n % m);
+/* Compute the greatest common divisor of positive integers */
+int gcd(int x, int y) {
+  int g;
+  g = y;
+  while (x > 0) {
+    g = x;
+    x = y % x;
+    y = g;
+  }
+  return g;
 }
 
 
-char *get_time() {
-    long            ltime;
-    time(&ltime);
-    return ctime(&ltime);
-}

Examples/mzscheme/simple/example.i

@@ -1,16 +1,7 @@
 /* File : example.i */
 %module example
-%{
-/* Put headers and other declarations here */
-%}
-
-%include typemaps.i
-
-%rename(mod) my_mod;
 
 %inline %{
-extern double My_variable;
-extern int    fact(int);
-extern int    my_mod(int n, int m);
-extern char   *get_time();
+extern int    gcd(int x, int y);
+extern double Foo;
 %}

Examples/mzscheme/simple/runme.scm

@@ -2,23 +2,30 @@
 
 (load-extension "example.so")
 
-(display (get-time))
+; Call our gcd() function
 
-(printf "My-variable = ~a~n" (My-variable))
+(define x 42)
+(define y 105)
+(define g (gcd x y))
+(display "The gcd of ")
+(display x)
+(display " and ")
+(display y)
+(display " is ")
+(display g)
+(newline)
 
-(let loop ((i 0))
-  (when (< i 14) (begin (display i)
-			(display " factorial is ")
-			(display (fact i))
-			(newline)
-			(loop (+ i 1)))))
+; Manipulate the Foo global variable
 
-(let loop ((i 1))
-  (when (< i 250)
-	(begin
-	  (let loopi ((j 1))
-	    (when (< j 250) (begin (My-variable (+ (My-variable) (mod i j)))
-				   (loopi (+ j 1)))))
-	  (loop (+ i 1)))))
+; Output its current value
+(display "Foo = ")
+(display (Foo))
+(newline)
 
-(printf "My-variable = ~a~n" (My-variable))
+; Change its value
+(Foo 3.1415926)
+
+; See if the change took effect
+(display "Foo = ")
+(display (Foo))
+(newline)