Fixes issue #2

cartoonist · Jun 10, 2017 · 94c6975 · 94c6975
1 parent 875b02b
commit 94c6975
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Showing 2 changed files with 23 additions and 9 deletions.
diff --git a/src/vargraph.cc b/src/vargraph.cc
@@ -329,8 +329,7 @@ namespace grem
   template < >
     bool at_end ( GraphIter < VarGraph, Backtracker<> > &it )
     {
-      return it.visiting_buffer.empty() &&
-        !it.vargraph_ptr->has_fwd_edge(*it);
+      return it.state.end;
     }  /* -----  end of template function at_end  ----- */
 
   template < >
@@ -349,7 +348,9 @@ namespace grem
 
       begin_itr.vargraph_ptr = &g;
       begin_itr.itr_value = start_node_id;
-      begin_itr.visited.push_back(0);  // Next node ID from current node. 0 = nothing buffered.
+      begin_itr.state.buffer = 0;
+      begin_itr.state.end = false;
+      begin_itr.state.start = start_node_id;
 
       return begin_itr;
     }  /* -----  end of template function begin  ----- */
@@ -360,9 +361,9 @@ namespace grem
     GraphIter < VarGraph, Backtracker <> > &
     GraphIter < VarGraph, Backtracker <> >::operator++ ( )
     {
-      if ( this->visited[0] != 0 ) {                             // Any node buffered?
-        this->itr_value = this->visited[0];                      // Use it.
-        this->visited[0] = 0;                                    // Clear up buffer.
+      if ( this->state.buffer != 0 ) {                             // Any node buffered?
+        this->itr_value = this->state.buffer;                      // Use it.
+        this->state.buffer = 0;                                    // Clear up buffer.
       }
       else {                                                  // else
         Backtracker<>::Value cnode_id = this->itr_value;
@@ -375,6 +376,9 @@ namespace grem
             this->visiting_buffer.push_back ( std::make_pair(cnode_id, edges[i]->to()) );
           }
         }
+        else {
+          this->state.end = true;
+        }
       }
 
       return *this;
@@ -384,18 +388,23 @@ namespace grem
     GraphIter < VarGraph, Backtracker <> > &
     GraphIter < VarGraph, Backtracker <> >::operator-- ( )
     {
-      if ( this->visited[0] != 0 ) {                             // Any node buffered?
+      if ( this->state.buffer != 0 ) {                             // Any node buffered?
         while (                // Remove all buffered branches of the current node.
             !this->visiting_buffer.empty() &&
             this->visiting_buffer.back().first == this->itr_value ) {
           this->visiting_buffer.pop_back();
         }
+        this->state.buffer = 0;
       }
 
       if ( !this->visiting_buffer.empty() ) {                 // Go back in buffer.
         this->itr_value = this->visiting_buffer.back().first;
-        this->visited[0] = this->visiting_buffer.back().second;
+        this->state.buffer = this->visiting_buffer.back().second;
         this->visiting_buffer.pop_back();
+        this->state.end = false;  // Reset at-end flag.
+      }
+      else {
+        this->state.end = true;  // Set at-end flag.
       }
 
       return *this;

diff --git a/src/vargraph.h b/src/vargraph.h
@@ -211,7 +211,12 @@ namespace grem
       typedef VarGraph::NodeID Value;
       typedef Value Level;
       typedef std::deque< std::pair< Value, Value > > TContainer;
-      typedef std::vector< Value > TSet;        /**< @brief Used as a buffer. */
+      typedef void* TSet;
+      typedef struct {
+        VarGraph::NodeID start;                 /**< @brief Start node ID. */
+        VarGraph::NodeID buffer;                /**< @brief Buffer node ID. 0=nothing */
+        bool end;                               /**< @brief End flag. */
+      } TState;
     };  /* ----------  end of struct Backtracker  ---------- */
 
   template < typename TSpec = void >