symmetry::calchash(): be careful to not dereference past-the-end iterator.

[ginac.git] / ginac / symmetry.cpp

diff --git a/ginac/symmetry.cpp b/ginac/symmetry.cpp
index 9cee0ffb37b24ec718cabf91c3897307ff3c9fab..725506fa6fa5a8e4af653c9c647ff33ad020834e 100644 (file)
--- a/ginac/symmetry.cpp
+++ b/ginac/symmetry.cpp
@@ -3,7 +3,7 @@
  *  Implementation of GiNaC's symmetry definitions. */
 
 /*
- *  GiNaC Copyright (C) 1999-2006 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2009 Johannes Gutenberg University Mainz, Germany
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -20,16 +20,18 @@
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-#include <iostream>
-#include <stdexcept>
-#include <functional>
-
 #include "symmetry.h"
 #include "lst.h"
 #include "numeric.h" // for factorial()
 #include "operators.h"
 #include "archive.h"
 #include "utils.h"
+#include "hash_seed.h"
+
+#include <functional>
+#include <iostream>
+#include <limits>
+#include <stdexcept>
 
 namespace GiNaC {
 
@@ -55,7 +57,7 @@ GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(symmetry, basic,
 // default constructor
 //////////
 
-symmetry::symmetry() : inherited(&symmetry::tinfo_static), type(none)
+symmetry::symmetry() :  type(none)
 {
        setflag(status_flags::evaluated | status_flags::expanded);
 }
@@ -64,13 +66,13 @@ symmetry::symmetry() : inherited(&symmetry::tinfo_static), type(none)
 // other constructors
 //////////
 
-symmetry::symmetry(unsigned i) : inherited(&symmetry::tinfo_static), type(none)
+symmetry::symmetry(unsigned i) :  type(none)
 {
        indices.insert(i);
        setflag(status_flags::evaluated | status_flags::expanded);
 }
 
-symmetry::symmetry(symmetry_type t, const symmetry &c1, const symmetry &c2) : inherited(&symmetry::tinfo_static), type(t)
+symmetry::symmetry(symmetry_type t, const symmetry &c1, const symmetry &c2) :  type(t)
 {
        add(c1); add(c2);
        setflag(status_flags::evaluated | status_flags::expanded);
@@ -81,8 +83,9 @@ symmetry::symmetry(symmetry_type t, const symmetry &c1, const symmetry &c2) : in
 //////////
 
 /** Construct object from archive_node. */
-symmetry::symmetry(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
+void symmetry::read_archive(const archive_node &n, lst &sym_lst)
 {
+       inherited::read_archive(n, sym_lst);
        unsigned t;
        if (!(n.find_unsigned("type", t)))
                throw (std::runtime_error("unknown symmetry type in archive"));
@@ -109,6 +112,7 @@ symmetry::symmetry(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
                }
        }
 }
+GINAC_BIND_UNARCHIVER(symmetry);
 
 /** Archive the object. */
 void symmetry::archive(archive_node &n) const
@@ -132,8 +136,6 @@ void symmetry::archive(archive_node &n) const
        }
 }
 
-DEFAULT_UNARCHIVE(symmetry)
-
 //////////
 // functions overriding virtual functions from base classes
 //////////
@@ -184,11 +186,12 @@ int symmetry::compare_same_type(const basic & other) const
 
 unsigned symmetry::calchash() const
 {
-       unsigned v = golden_ratio_hash((p_int)tinfo());
+       unsigned v = make_hash_seed(typeid(*this));
 
        if (type == none) {
                v = rotate_left(v);
-               v ^= *(indices.begin());
+               if (!indices.empty())
+                       v ^= *(indices.begin());
        } else {
                for (exvector::const_iterator i=children.begin(); i!=children.end(); ++i)
                {
@@ -266,6 +269,18 @@ void symmetry::do_print_tree(const print_tree & c, unsigned level) const
 // non-virtual functions in this class
 //////////
 
+bool symmetry::has_cyclic() const
+{
+       if (type == cyclic)
+               return true;
+
+       for (exvector::const_iterator i=children.begin(); i!=children.end(); ++i)
+               if (ex_to<symmetry>(*i).has_cyclic())
+                       return true;
+
+       return false;
+}
+
 symmetry &symmetry::add(const symmetry &c)
 {
        // All children must have the same number of indices
@@ -419,7 +434,7 @@ int canonicalize(exvector::iterator v, const symmetry &symm)
 {
        // Less than two elements? Then do nothing
        if (symm.indices.size() < 2)
-               return INT_MAX;
+               return std::numeric_limits<int>::max();
 
        // Canonicalize children first
        bool something_changed = false;
@@ -430,7 +445,7 @@ int canonicalize(exvector::iterator v, const symmetry &symm)
                int child_sign = canonicalize(v, ex_to<symmetry>(*first));
                if (child_sign == 0)
                        return 0;
-               if (child_sign != INT_MAX) {
+               if (child_sign != std::numeric_limits<int>::max()) {
                        something_changed = true;
                        sign *= child_sign;
                }
@@ -457,7 +472,7 @@ int canonicalize(exvector::iterator v, const symmetry &symm)
                default:
                        break;
        }
-       return something_changed ? sign : INT_MAX;
+       return something_changed ? sign : std::numeric_limits<int>::max();
 }