Implement jet for ++rev.

include/jets/k.h

@@ -43,6 +43,11 @@
     u3_noun
     u3kc_rip(u3_atom a, u3_atom b);
 
+  /* u3kc_rev(): reverse block order, accounting for leading zeroes.
+  */
+    u3_noun
+    u3kc_rev(u3_atom boz, u3_atom len, u3_atom dat);
+
   /* u3kc_swp(): reverse block order.
   */
     u3_noun

include/jets/q.h

@@ -64,6 +64,7 @@
     u3_noun u3qc_pow(u3_atom, u3_atom);
     u3_noun u3qc_rap(u3_atom, u3_noun);
     u3_noun u3qc_rep(u3_atom, u3_noun);
+    u3_noun u3qc_rev(u3_atom, u3_atom, u3_atom);
     u3_noun u3qc_rip(u3_atom, u3_atom);
     u3_noun u3qc_rsh(u3_atom, u3_atom, u3_atom);
     u3_noun u3qc_swp(u3_atom, u3_atom);

include/jets/w.h

@@ -64,6 +64,7 @@
     u3_noun u3wc_pow(u3_noun);
     u3_noun u3wc_rap(u3_noun);
     u3_noun u3wc_rep(u3_noun);
+    u3_noun u3wc_rev(u3_noun);
     u3_noun u3wc_rip(u3_noun);
     u3_noun u3wc_rsh(u3_noun);
     u3_noun u3wc_swp(u3_noun);

jets/c/rev.c

@@ -0,0 +1,50 @@
+/* j/3/rev.c
+**
+*/
+#include "all.h"
+
+/* functions
+*/
+
+  u3_noun
+  u3qc_rev(u3_atom boz,
+           u3_atom len,
+           u3_atom dat)
+  {
+    if ( !_(u3a_is_cat(boz)) || (boz >= 32) ||
+         !_(u3a_is_cat(len)) ) {
+      return u3m_bail(c3__fail);
+    }
+
+    dat = u3qc_end(boz, len, dat);
+    c3_w met = u3r_met(boz, dat);
+    return u3kc_lsh(u3k(boz), (len - met), u3kc_swp(u3k(boz), dat));
+  }
+
+  u3_noun
+  u3wc_rev(u3_noun cor)
+  {
+    u3_noun boz, len, dat;
+
+    if ( (c3n == u3r_mean(cor, u3x_sam_2, &boz,
+                               u3x_sam_6, &len,
+                               u3x_sam_7, &dat, 0)) ||
+         (c3n == u3ud(boz)) ||
+         (c3n == u3ud(len)) ||
+         (c3n == u3ud(dat)) )
+    {
+      return u3m_bail(c3__exit);
+    } else {
+      return u3qc_rev(boz, len, dat);
+    }
+  }
+
+  u3_noun
+  u3kc_rev(u3_atom boz,
+           u3_atom len,
+           u3_atom dat)
+  {
+    u3_noun res = u3qc_rev(boz, len, dat);
+    u3z(boz); u3z(len); u3z(dat);
+    return res;
+  }

jets/tree.c

@@ -510,6 +510,7 @@ static u3j_core _143_tri_d[] =
   static u3j_harm _143_two_pow_a[] = {{".2", u3wc_pow, c3y}, {}};
   static u3j_harm _143_two_rap_a[] = {{".2", u3wc_rap, c3y}, {}};
   static u3j_harm _143_two_rep_a[] = {{".2", u3wc_rep, c3y}, {}};
+  static u3j_harm _143_two_rev_a[] = {{".2", u3wc_rev, c3y}, {}};
   static u3j_harm _143_two_rip_a[] = {{".2", u3wc_rip, c3y}, {}};
   static u3j_harm _143_two_rsh_a[] = {{".2", u3wc_rsh, c3y}, {}};
   static u3j_harm _143_two_swp_a[] = {{".2", u3wc_swp, c3y}, {}};
@@ -614,6 +615,7 @@ static u3j_core _143_two_d[] =
     { "muk", _143_two_muk_a },
     { "rap", _143_two_rap_a },
     { "rep", _143_two_rep_a },
+    { "rev", _143_two_rev_a },
     { "rip", _143_two_rip_a },
     { "rsh", _143_two_rsh_a },
     { "rub", _143_two_rub_a },

meson.build

@@ -71,6 +71,7 @@ jets_c_src = [
 'jets/c/pow.c',
 'jets/c/rap.c',
 'jets/c/rep.c',
+'jets/c/rev.c',
 'jets/c/rip.c',
 'jets/c/rsh.c',
 'jets/c/swp.c',