fib added

Author: kassane

build.sh

@@ -7,7 +7,7 @@ cd c64/hello
 bash build.sh
 ls -lh
 cd $ROOTPATH
-# cd c64/fibonacci
-# bash build.sh
-# ls -lh
-# cd $ROOTPATH
+cd c64/fibonacci
+bash build.sh
+ls -lh
+cd $ROOTPATH

c64/fibonacci/build.sh

@@ -2,11 +2,12 @@
 
 ldmd2 -i \
     -betterC \
-    -I ../../modules/common \
-    hello.d \
+    -I$PWD/../../modules \
+    src/fib.d \
     -mtriple=mos-unknown-unknown \
     --release \
     -O \
+    -L-lprintf_flt \
     -of=fib.prg \
     -gcc=mos-c64-clang \
     -linker=lld

c64/fibonacci/src/fib.d

@@ -0,0 +1,29 @@
+import common : printf;
+
+T fibonacci(T)(T n)
+{
+    static if (is(T == int))
+    {
+        T go(T n, T prev, T curr)
+        {
+            if (n == 0)
+                return prev;
+            else
+                return go(n - 1, curr, prev + curr);
+        }
+
+        return go(n, 0, 1);
+
+    }
+    else
+    {
+        static assert(0, "fibonacci only supports integers");
+    }
+}
+
+extern (C)
+void main()
+{
+    auto n = 100;
+    printf("Fibonacci number %d is %d\n", n, fibonacci(n));
+}

c64/hello/src/hello.d

@@ -1,6 +1,7 @@
-import common: printf;
+import common : printf;
 
-extern(C)
-void main() {
+extern (C)
+void main()
+{
     printf("Hello World in D!\n");
-}
+}