1 files changed, 44 insertions, 0 deletions
diff --git a/vere/pkg/noun/jets/b/roll.c b/vere/pkg/noun/jets/b/roll.c
new file mode 100644
index 0000000..66a4726
--- /dev/null
+++ b/vere/pkg/noun/jets/b/roll.c
@@ -0,0 +1,44 @@
+/// @file
+
+#include "jets/q.h"
+#include "jets/w.h"
+
+#include "noun.h"
+
+  u3_noun
+  u3qb_roll(u3_noun a,
+            u3_noun b)
+  {
+    u3_noun pro = u3k(u3x_at(u3x_sam_3, b));
+
+    if ( u3_nul != a ) {
+      u3j_site sit_u;
+      u3_noun  i, t;
+      u3j_gate_prep(&sit_u, u3k(b));
+      u3k(a);
+
+      do {
+        i = u3h(a);
+
+        pro = u3j_gate_slam(&sit_u, u3nc(u3k(i), pro));
+        
+        t = u3k(u3t(a));
+        u3z(a), a = t;
+      } while ( u3_nul != a );
+      u3j_gate_lose(&sit_u);
+    }
+
+    return pro;
+  }
+  u3_noun
+  u3wb_roll(u3_noun cor)
+  {
+    u3_noun a, b;
+
+    if ( c3n == u3r_mean(cor, u3x_sam_2, &a, u3x_sam_3, &b, 0) ) {
+      return u3m_bail(c3__exit);
+    } else {
+      return u3qb_roll(a, b);
+    }
+  }
+