- Some unfolding of tuple goals towards getting -m2 Arachne to work.

src/arachne.c

@@ -1279,6 +1279,37 @@ termBindConsequences (Term t)
 // Larger logical componentents
 //------------------------------------------------------------------------
 
+//! Selector to select the first tuple goal.
+/**
+ * Basically to get rid of -m2 tuple goals.
+ * Nice iteration, I'd suppose
+ */
+Binding
+select_tuple_goal()
+{
+  List bl;
+  Binding tuplegoal;
+
+  bl = sys->bindings;
+  tuplegoal = NULL;
+  while (bl != NULL && tuplegoal == NULL)
+    {
+      Binding b;
+
+      b = (Binding) bl->data;
+      // Ignore done stuff
+      if (!b->done)
+	{
+	  if (isTermTuple (b->term))
+	    {
+	      tuplegoal = b;
+	    }
+	}
+      bl = bl->next;
+    }
+  return tuplegoal;
+}
+
 //! Goal selection
 /**
  * Selects the most constrained goal.
@@ -2237,6 +2268,41 @@ iterate ()
 	    {
 	      Binding b;
 
+	      // Are there any tuple goals?
+	      b = select_tuple_goal();
+	      if (b != NULL)
+		{
+		  // Expand tuple goal
+		  int count;
+		  Term tt;
+	
+		  // Show this in output
+		  if (sys->output == PROOF)
+		    {
+		      indentPrint ();
+		      eprintf ("Expanding tuple goal ");
+		      termPrint (b->term);
+		      eprintf ("\n");
+		    }
+
+		  // mark as done for iteration
+		  b->done = 1;
+
+		  // simply adding will detect the tuple and add the new subgoals
+		  count = goal_add (b->term, b->run_to, b->ev_to, b->level);
+
+		  // iterate
+		  flag = iterate ();
+
+		  // undo
+  		  goal_remove_last (count);
+		  b->done = 0;
+		}
+	      else
+		{
+		  // No tuple goals; good
+		  Binding b;
+
 		  /**
 		   * Not pruned: count
 		   */
@@ -2271,6 +2337,7 @@ iterate ()
 		      flag = bind_goal (b);
 		    }
 		}
+	    }
 	  else
 	    {
 	      // Pruned because of bound!