Use the new parser in the ex(const string&, lst&) ctor.

[ginac.git] / ginac / symbol.h

diff --git a/ginac/symbol.h b/ginac/symbol.h
index 9c7e526d6dca881b89c35a49e39fff2feb89c27b..c174ad5f5136b10e83d8dc0dc1cf526b07b142d6 100644 (file)
--- a/ginac/symbol.h
+++ b/ginac/symbol.h
@@ -3,7 +3,7 @@
  *  Interface to GiNaC's symbolic objects. */
 
 /*
- *  GiNaC Copyright (C) 1999-2006 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2008 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
@@ -31,26 +31,13 @@
 namespace GiNaC {
 
 /** Basic CAS symbol.  It has a name because it must know how to output itself.
- *  It may be assigned an expression, but this feature is only intended for
- *  programs like 'ginsh' that want to associate symbols with expressions.
- *  If you want to replace symbols by expressions in your code, you should
- *  use ex::subs() or use objects of class ex instead of class symbol in the
- *  first place. */
+ */
 class symbol : public basic
 {
        GINAC_DECLARE_REGISTERED_CLASS(symbol, basic)
 
        friend class realsymbol;
-
-// types
-       
-       /** Symbols as keys to expressions - only for ginsh. */
-       class assigned_ex_info : public refcounted {
-       public:
-               assigned_ex_info() throw();  ///< Default ctor
-               bool is_assigned;            ///< True if there is an expression assigned
-               ex assigned_expression;      ///< The actual expression
-       };
+       friend class possymbol;
 
 // member functions
        
@@ -65,7 +52,7 @@ public:
        // functions overriding virtual functions from base classes
 public:
        bool info(unsigned inf) const;
-       ex eval(int level = 0) const;
+       ex eval(int level = 0) const { return *this; } // for performance reasons
        ex evalf(int level = 0) const { return *this; } // overwrites basic::evalf() for performance reasons
        ex series(const relational & s, int order, unsigned options = 0) const;
        ex subs(const exmap & m, unsigned options = 0) const { return subs_one_level(m, options); } // overwrites basic::subs() for performance reasons
@@ -85,8 +72,6 @@ protected:
        
        // non-virtual functions in this class
 public:
-       void assign(const ex & value);
-       void unassign();
        void set_name(const std::string & n) { name = n; }
        std::string get_name() const { return name; }
        unsigned get_domain() const { return domain; }
@@ -102,7 +87,6 @@ private:
 // member variables
 
 protected:
-       ptr<assigned_ex_info> asexinfop; ///< assigned expression, only for private use by ginsh
        unsigned serial;                 ///< unique serial number for comparison
        std::string name;                ///< printname of this symbol
        std::string TeX_name;            ///< LaTeX name of this symbol
@@ -127,17 +111,38 @@ public:
 };
 
 
+/** Specialization of symbol to real domain */
+class possymbol : public symbol
+{
+       // constructors
+public:
+       possymbol();
+       explicit possymbol(const std::string & initname, unsigned domain = domain::positive);
+       possymbol(const std::string & initname, const std::string & texname, unsigned domain = domain::positive);
+       possymbol(const std::string & initname, unsigned rt, tinfo_t rtt, unsigned domain = domain::positive);
+       possymbol(const std::string & initname, const std::string & texname, unsigned rt, tinfo_t rtt, unsigned domain = domain::positive);
+};
+
+
 // utility functions
 
 /** Specialization of is_exactly_a<realsymbol>(obj) for realsymbol objects. */
 template<> inline bool is_exactly_a<realsymbol>(const basic & obj)
 {
-       return (obj.tinfo() == &symbol::tinfo_static) && (static_cast<const symbol &>(obj).get_domain() == domain::real);
+       if (obj.tinfo() != &symbol::tinfo_static)
+               return false;
+       unsigned domain = static_cast<const symbol &>(obj).get_domain();
+       return domain==domain::real || domain==domain::positive;
 }
 
-// wrapper functions around member functions
-inline void unassign(symbol & symarg)
-{ symarg.unassign(); }
+/** Specialization of is_exactly_a<possymbol>(obj) for possymbol objects. */
+template<> inline bool is_exactly_a<possymbol>(const basic & obj)
+{
+       if (obj.tinfo() != &symbol::tinfo_static)
+               return false;
+       unsigned domain = static_cast<const symbol &>(obj).get_domain();
+       return domain == domain::positive;
+}
 
 } // namespace GiNaC