/** @file pseries.h
 *
 *  Interface to class for extended truncated power series. */

/*
 *  GiNaC Copyright (C) 1999-2000 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
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  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
 */

#ifndef __GINAC_SERIES_H__
#define __GINAC_SERIES_H__

#include "basic.h"
#include "expairseq.h"

#ifndef NO_NAMESPACE_GINAC
namespace GiNaC {
#endif // ndef NO_NAMESPACE_GINAC

/** This class holds a extended truncated power series (positive and negative
 *  integer powers). It consists of expression coefficients (only non-zero
 *  coefficients are stored), an expansion variable and an expansion point.
 *  Other classes must provide members to convert into this type. */
class pseries : public basic
{
    GINAC_DECLARE_REGISTERED_CLASS(pseries, basic)

    // default constructor, destructor, copy constructor, assignment operator and helpers
public:
    pseries();
    ~pseries();
    pseries(const pseries &other);
    const pseries &operator=(const pseries &other);
protected:
    void copy(const pseries &other);
    void destroy(bool call_parent);

    // other constructors
public:
    pseries(const ex &var_, const ex &point_, const epvector &ops_);

    // functions overriding virtual functions from base classes
public:
    basic *duplicate() const;
    void print(ostream &os, unsigned upper_precedence=0) const;
    void printraw(ostream &os) const;
    unsigned nops(void) const;
    ex op(int i) const;
    ex &let_op(int i);
    int degree(const symbol &s) const;
    int ldegree(const symbol &s) const;
    ex coeff(const symbol &s, int n=1) const;
    ex collect(const symbol &s) const;
    ex eval(int level=0) const;
    ex evalf(int level=0) const;
    ex series(const symbol & s, const ex & p, int order) const;
    ex normal(lst &sym_lst, lst &repl_lst, int level=0) const;
    ex subs(const lst & ls, const lst & lr) const;
protected:
    ex derivative(const symbol & s) const;

    // non-virtual functions in this class
public:
    ex convert_to_poly(bool no_order = false) const;
    bool is_compatible_to(const pseries &other) const {return var.compare(other.var) == 0 && point.compare(other.point) == 0;}
    bool is_zero(void) const {return seq.size() == 0;}
    ex add_series(const pseries &other) const;
    ex mul_const(const numeric &other) const;
    ex mul_series(const pseries &other) const;
    ex power_const(const numeric &p, int deg) const;

protected:
    /** Vector of {coefficient, power} pairs */
    epvector seq;

    /** Series variable (holds a symbol) */
    ex var;

    /** Expansion point */
    ex point;
};

// global constants
extern const pseries some_pseries;
extern const type_info & typeid_pseries;

/** Return a reference to the pseries object embedded in an expression.
 *  The result is undefined if the expression does not contain a pseries
 *  object at its top level.
 *
 *  @param e expression
 *  @return reference to pseries object
 *  @see is_ex_of_type */
inline const pseries &ex_to_pseries(const ex &e)
{
	return static_cast<const pseries &>(*e.bp);
}

/** Convert the pseries object embedded in an expression to an ordinary
 *  polynomial in the expansion variable. The result is undefined if the
 *  expression does not contain a pseries object at its top level.
 *
 *  @param e expression
 *  @return polynomial expression
 *  @see is_ex_of_type
 *  @see pseries::convert_to_poly */
inline ex series_to_poly(const ex &e)
{
	return (static_cast<const pseries &>(*e.bp).convert_to_poly(true));
}

#ifndef NO_NAMESPACE_GINAC
} // namespace GiNaC
#endif // ndef NO_NAMESPACE_GINAC

#endif // ndef __GINAC_SERIES_H__