refactor Coverind constructors

Split constructor in methods that are (will) reused elsewhere

coverind.hpp

@@ -63,6 +63,10 @@ public:
   size_t size_in_bytes() const;
   
   void save(const std::string) const;
+
+private:
+  void create_rank_select();
+  void build_from_bitvectors(const bit_vector &start_bv, const bit_vector &end_bv);
 };
 
 bit_vector create_bitvector_from_file(const std::string filename);
@@ -74,9 +78,22 @@ bit_vector create_bitvector_from_file(const std::string filename);
 
 template <class bv>
 Coverind<bv>::Coverind(const std::string start_file, const std::string end_file) {
-  start = bv(create_bitvector_from_file(start_file));
-  end = bv(create_bitvector_from_file(end_file));
+  bit_vector start_bv = create_bitvector_from_file(start_file);
+  bit_vector end_bv = create_bitvector_from_file(end_file);
+  build_from_bitvectors(start_bv, end_bv);
+}
+
+
+template<class bv>
+void Coverind<bv>::build_from_bitvectors(const bit_vector &start_bv, const bit_vector &end_bv) {
+  start = bv(start_bv);
+  end = bv(end_bv);
+
+  create_rank_select();
+}
 
+template <class bv>
+void Coverind<bv>::create_rank_select() {
   rank_start = typename bv::rank_1_type(&start);
   rank_end = typename bv::rank_1_type(&end);
 
@@ -89,11 +106,7 @@ Coverind<bv>::Coverind(const std::string index) {
   load_from_file(start, index+std::string(".start.bv"));
   load_from_file(end, index +std::string(".end.bv"));
 
-  rank_start = typename bv::rank_1_type(&start);
-  rank_end = typename bv::rank_1_type(&end);
-
-  select_start = typename bv::select_0_type(&start);
-  select_end = typename bv::select_0_type(&end);
+  create_rank_select();
 }
                        
 template <class bv>