add metalang99 testsuite (preprocessor stress testing)

1 files changed, 48 insertions, 0 deletions

diff --git a/test/external/metalang99/examples/demo.c b/test/external/metalang99/examples/demo.c
new file mode 100644
index 0000000..4a209d9
--- /dev/null
+++ b/test/external/metalang99/examples/demo.c
@@ -0,0 +1,48 @@
+// `...` is sometimes used to workaround a TCC bug, see
+// <https://github.com/hirrolot/datatype99/issues/10#issuecomment-830813172>.
+
+#include <metalang99.h>
+
+// Compile-time list manipulation:
+
+// 3, 3, 3, 3, 3
+static int five_threes[] = {
+    ML99_LIST_EVAL_COMMA_SEP(ML99_listReplicate(v(5), v(3))),
+};
+
+// 5, 4, 3, 2, 1
+static int from_5_to_1[] = {
+    ML99_LIST_EVAL_COMMA_SEP(ML99_listReverse(ML99_list(v(1, 2, 3, 4, 5)))),
+};
+
+// 9, 2, 5
+static int lesser_than_10[] = {
+    ML99_LIST_EVAL_COMMA_SEP(
+        ML99_listFilter(ML99_appl(v(ML99_greater), v(10)), ML99_list(v(9, 2, 11, 13, 5)))),
+};
+
+// Macro recursion:
+#define factorial(n)          ML99_natMatch(n, v(factorial_))
+#define factorial_Z_IMPL(...) v(1) // `...` due to the TCC's bug.
+#define factorial_S_IMPL(n)   ML99_mul(ML99_inc(v(n)), factorial(v(n)))
+
+ML99_ASSERT_EQ(factorial(v(4)), v(24));
+
+// Overloading on a number of arguments:
+typedef struct {
+    double width, height;
+} Rect;
+
+#define Rect_new(...) ML99_OVERLOAD(Rect_new_, __VA_ARGS__)
+#define Rect_new_1(x)                                                                              \
+    { x, x }
+#define Rect_new_2(x, y)                                                                           \
+    { x, y }
+
+static Rect _7x8 = Rect_new(7, 8), _10x10 = Rect_new(10);
+
+// ... and more!
+
+int main(void) {
+    // Yeah. All is done at compile time.
+}