1 files changed, 39 insertions, 0 deletions
diff --git a/vere/pkg/noun/jets/f/flip.c b/vere/pkg/noun/jets/f/flip.c
new file mode 100644
index 0000000..9eb922e
--- /dev/null
+++ b/vere/pkg/noun/jets/f/flip.c
@@ -0,0 +1,39 @@
+/// @file
+
+#include "jets/q.h"
+#include "jets/w.h"
+
+#include "noun.h"
+
+
+  u3_noun
+  u3qf_flip(u3_noun hel)
+  {
+    if ( c3y == u3r_sing(1, u3h(hel)) ) {
+      if ( (c3y == u3t(hel)) ) {
+        return u3nc(1, c3n);
+      }
+      else {
+        u3_assert((c3n == u3t(hel)));
+
+        return u3nc(1, c3y);
+      }
+    }
+    else {
+      return u3nq(6,
+                  u3k(hel),
+                  u3nc(1, c3n),
+                  u3nc(1, c3y));
+    }
+  }
+  u3_noun
+  u3wf_flip_139(u3_noun cor)
+  {
+    u3_noun hel;
+
+    if ( u3_none == (hel = u3r_at(u3x_sam, cor)) ) {
+      return u3m_bail(c3__fail);
+    } else {
+      return u3qf_flip(hel);
+    }
+  }