Make step(0)=1/2 again and remove step_power.

[ginac.git] / ginac / numeric.h

diff --git a/ginac/numeric.h b/ginac/numeric.h
index ac1d5b8a1271f2db55361e30fc4537ccdbc42155..f0e3362f8965aec7bcd5aaf199e6d65f1f3362d7 100644 (file)
--- a/ginac/numeric.h
+++ b/ginac/numeric.h
@@ -3,7 +3,7 @@
  *  Makes the interface to the underlying bignum package available. */
 
 /*
- *  GiNaC Copyright (C) 1999-2005 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2006 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
@@ -17,7 +17,7 @@
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
 #ifndef __GINAC_NUMERIC_H__
@@ -27,6 +27,7 @@
 #include "ex.h"
 
 #include <stdexcept>
+#include <vector>
 
 #include <cln/complex.h>
 
@@ -39,6 +40,12 @@
 
 namespace GiNaC {
 
+/** Function pointer to implement callbacks in the case 'Digits' gets changed.
+ *  Main purpose of such callbacks is to adjust look-up tables of certain
+ *  functions to the new precision. Parameter contains the signed difference
+ *  between new Digits and old Digits. */
+typedef void (* digits_changed_callback)(long);
+
 /** This class is used to instantiate a global singleton object Digits
  *  which behaves just like Maple's Digits.  We need an object rather 
  *  than a dumber basic type since as a side-effect we let it change
@@ -55,11 +62,14 @@ public:
        _numeric_digits();
        _numeric_digits& operator=(long prec);
        operator long();
-       void print(std::ostream &os) const;
+       void print(std::ostream& os) const;
+       void add_callback(digits_changed_callback callback);
 // member variables
 private:
        long digits;                        ///< Number of decimal digits
        static bool too_late;               ///< Already one object present
+       // Holds a list of functions that get called when digits is changed.
+       std::vector<digits_changed_callback> callbacklist;
 };
 
 
@@ -98,7 +108,7 @@ public:
        int degree(const ex & s) const;
        int ldegree(const ex & s) const;
        ex coeff(const ex & s, int n = 1) const;
-       bool has(const ex &other) const;
+       bool has(const ex &other, unsigned options = 0) const;
        ex eval(int level = 0) const;
        ex evalf(int level = 0) const;
        ex subs(const exmap & m, unsigned options = 0) const { return subs_one_level(m, options); } // overwrites basic::subs() for performance reasons
@@ -138,6 +148,7 @@ public:
        const numeric & operator=(double d);
        const numeric & operator=(const char *s);
        const numeric inverse() const;
+       numeric step() const;
        int csgn() const;
        int compare(const numeric &other) const;
        bool is_equal(const numeric &other) const;
@@ -240,6 +251,9 @@ inline const numeric pow(const numeric &x, const numeric &y)
 inline const numeric inverse(const numeric &x)
 { return x.inverse(); }
 
+inline numeric step(const numeric &x)
+{ return x.step(); }
+
 inline int csgn(const numeric &x)
 { return x.csgn(); }
 
@@ -307,14 +321,6 @@ ex EulerEvalf();
 ex CatalanEvalf();
 
 
-// utility functions
-
-/** Specialization of is_exactly_a<numeric>(obj) for numeric objects. */
-template<> inline bool is_exactly_a<numeric>(const basic & obj)
-{
-       return obj.tinfo()==TINFO_numeric;
-}
-
 } // namespace GiNaC
 
 #ifdef __MAKECINT__