fix rust macro arguments

2 files changed, 58 insertions, 0 deletions

diff --git a/testing/templates/rust-macro-args.html b/testing/templates/rust-macro-args.html
new file mode 100644
index 0000000..b009a73
--- /dev/null
+++ b/testing/templates/rust-macro-args.html
@@ -0,0 +1,26 @@
+{{
+        call_a_or_b_on_tail!(
+            (a: compute_len, b: zero),
+                the recursive part that skips over all these
+                tokens doesn't much care whether we will call a
+                or call b: only the terminal rules care.
+        )
+}}
+{{
+        call_a_or_b_on_tail!(
+            (a: compute_len, b: zero),
+                and now, to justify the existence of two paths
+                we will also call a: its input should somehow
+                be self-referential, so let's make it return
+                some ninety one!
+        )
+}}
+{{
+        call_a_or_b_on_tail!(
+            (a: compute_len, b: zero),
+                and now, to justify the existence of two paths
+                we will also call a: its input should somehow
+                be self-referential, so let's make it return
+                some ninety "(\"()"nine!
+        )
+}}
diff --git a/testing/tests/rust_macro.rs b/testing/tests/rust_macro.rs
index 8a114f9..b92bbeb 100644
--- a/testing/tests/rust_macro.rs
+++ b/testing/tests/rust_macro.rs
@@ -15,3 +15,35 @@ fn main() {
     let template = RustMacrosTemplate {};
     assert_eq!("Hello, world!", template.render().unwrap());
 }
+
+macro_rules! call_a_or_b_on_tail {
+    ((a: $a:expr, b: $b:expr), call a: $($tail:tt)*) => {
+        $a(stringify!($($tail)*))
+    };
+
+    ((a: $a:expr, b: $b:expr), call b: $($tail:tt)*) => {
+        $b(stringify!($($tail)*))
+    };
+
+    ($ab:tt, $_skip:tt $($tail:tt)*) => {
+        call_a_or_b_on_tail!($ab, $($tail)*)
+    };
+}
+
+fn compute_len(s: &str) -> usize {
+    s.len()
+}
+
+fn zero(_s: &str) -> usize {
+    0
+}
+
+#[derive(Template)]
+#[template(path = "rust-macro-args.html")]
+struct RustMacrosArgTemplate {}
+
+#[test]
+fn args() {
+    let template = RustMacrosArgTemplate {};
+    assert_eq!("0\n91\n99", template.render().unwrap());
+}