calchash(): work around broken RTTI.

[ginac.git] / ginac / symbol.cpp

diff --git a/ginac/symbol.cpp b/ginac/symbol.cpp
index 9a729919fcd6ed4d732752cbcd281666f7a6e452..a736088903872dd854dfe55c34020a08a6aed1ea 100644 (file)
--- a/ginac/symbol.cpp
+++ b/ginac/symbol.cpp
@@ -3,7 +3,7 @@
  *  Implementation of GiNaC's symbolic objects. */
 
 /*
- *  GiNaC Copyright (C) 1999-2008 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
@@ -20,17 +20,18 @@
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-#include <string>
-#include <stdexcept>
-#include <map>
-
 #include "symbol.h"
 #include "lst.h"
 #include "archive.h"
 #include "tostring.h"
 #include "utils.h"
+#include "hash_seed.h"
 #include "inifcns.h"
 
+#include <map>
+#include <stdexcept>
+#include <string>
+
 namespace GiNaC {
 
 GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(symbol, basic,
@@ -96,31 +97,28 @@ possymbol::possymbol(const std::string & initname, const std::string & texname)
 // archiving
 //////////
 
-/** Construct object from archive_node. */
-symbol::symbol(const archive_node &n, lst &sym_lst)
- : inherited(n, sym_lst), serial(next_serial++)
-{
-       if (!n.find_string("name", name))
-               name = std::string("");
-       if (!n.find_string("TeXname", TeX_name))
-               TeX_name = std::string("");
-       setflag(status_flags::evaluated | status_flags::expanded);
-}
-
-/** Unarchive the object. */
-ex symbol::unarchive(const archive_node &n, lst &sym_lst)
+/** Read object from archive_node. */
+void symbol::read_archive(const archive_node &n, lst &sym_lst)
 {
-       ex s = (new symbol(n, sym_lst))->setflag(status_flags::dynallocated);
+       inherited::read_archive(n, sym_lst);
+       serial = next_serial++;
+       std::string tmp_name;
+       n.find_string("name", tmp_name);
 
        // If symbol is in sym_lst, return the existing symbol
        for (lst::const_iterator it = sym_lst.begin(); it != sym_lst.end(); ++it) {
-               if (is_a<symbol>(*it) && (ex_to<symbol>(*it).name == ex_to<symbol>(s).name))
-                       return *it;
+               if (is_a<symbol>(*it) && (ex_to<symbol>(*it).name == tmp_name)) {
+                       *this = ex_to<symbol>(*it);
+                       return;
+               }
        }
+       name = tmp_name;
+       if (!n.find_string("TeXname", TeX_name))
+               TeX_name = std::string("");
+       setflag(status_flags::evaluated | status_flags::expanded);
 
-       // Otherwise add new symbol to list and return it
-       sym_lst.append(s);
-       return s;
+       setflag(status_flags::dynallocated);
+       sym_lst.append(*this);
 }
 
 /** Archive the object. */
@@ -256,8 +254,8 @@ bool symbol::is_equal_same_type(const basic & other) const
 
 unsigned symbol::calchash() const
 {
-       const void* this_tinfo = (const void*)typeid(*this).name();
-       hashvalue = golden_ratio_hash((p_int)this_tinfo ^ serial);
+       unsigned seed = make_hash_seed(typeid(*this));
+       hashvalue = golden_ratio_hash(seed ^ serial);
        setflag(status_flags::hash_calculated);
        return hashvalue;
 }
@@ -328,6 +326,10 @@ static const std::string& get_default_TeX_name(const std::string& name)
                return name;
 }
 
+GINAC_BIND_UNARCHIVER(symbol);
+GINAC_BIND_UNARCHIVER(realsymbol);
+GINAC_BIND_UNARCHIVER(possymbol);
+
 //////////
 // static member variables
 //////////