WIP: rewrite C++ backend to be CHEADmaster

+ C allows for a bit more control, and we can manually handle closure
  contexts. For example `examples/fib.fwd` now works for effectively any
  `n`, pretty cool.

+ Fairly slow Fibonacci, I must admit. Initial profiling indicates it's
  mainly due to branch mispredictions, but I'll have to look into this a
  bit deeper.

+ The code is a bit hacked together, for now I'm more interested in
  getting things working, I'll worry about making things pretty later.

+ For testing, there's also initial support for modules, just so I can
  print stuff to the terminal

+ This commit is way too big, lol

2 files changed, 41 insertions, 13 deletions

diff --git a/examples/fib.fwd b/examples/fib.fwd
index 7084b9d..e6d6ee6 100644
--- a/examples/fib.fwd
+++ b/examples/fib.fwd
@@ -1,25 +1,30 @@
-/* heh, this technically speaking works, but I guess the compiler can't collapse
- * frames so the bifurcating nature of fibonacci just gets mapped to a linear
- * sequence of calls, taking up way more stack space than a typical, returning,
- * function  */
+/*
+ * Currently the compilation process requires a bit of manual intervention.
+ * For this particular example, run something like this from the root dir:
+ *
+ *	./fwd examples/fib.fwd > /tmp/fib.c
+ *	gcc -Lmod -Iinclude -Ilib -Wl,-rpath=mod -O2 /tmp/fib.c -lfwdio -o /tmp/fib
+ *	/tmp/fib
+ *
+ */
 
-fib(int n, (int) res)
+/* modules are just libraries that can be loaded at runtime */
+import "../mod/libfwdio.so"
+
+fib(i64 n, (i64) res)
 {
 	if n < 2 {
 		res(1);
 	} else {
-		fib(n - 1) => int f1;
-		fib(n - 2) => int f2;
+		fib(n - 1) => i64 f1;
+		fib(n - 2) => i64 f2;
 		res(f1 + f2);
 	}
 }
 
-/* 'extern' println */
-fwd_println(auto n);
-fwd_copy(auto n, (auto, auto) n1);
-
 main()
 {
-	fib(6) => int n;
-	fwd_println(n);
+	fib(42) => i64 n;
+	print_i64(n);
+	print_nl();
 }
diff --git a/examples/sum.fwd b/examples/sum.fwd
new file mode 100644
index 0000000..89a2d11
--- /dev/null
+++ b/examples/sum.fwd
@@ -0,0 +1,23 @@
+print_int(i64 a);
+print_nl();
+
+sum_inner(i64 s, i64 n, (i64) res)
+{
+	if n <= 0 {
+		res(s);
+	} else {
+		sum_inner(s + n, n - 1, res);
+	}
+}
+
+sum(i64 n, (i64) res)
+{
+	sum_inner(0, n, res);
+}
+
+main()
+{
+	sum(1000000000) => i64 s;
+	print_int(s);
+	print_nl();
+}