/** @file ex.h
 *
 *  Interface to GiNaC's light-weight expression handles. */

/*
 *  GiNaC Copyright (C) 1999 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_EX_H__
#define __GINAC_EX_H__

#include <iostream>
#include <ginac/basic.h>
#include <ginac/operators.h>

namespace GiNaC {

class ex;
class expand_options;
class status_flags;

class symbol;
class lst;

typedef vector<ex> exvector;

// enum definitions

ex const & exZERO(void);
ex const & exONE(void);
ex const & exTWO(void);
ex const & exTHREE(void);
ex const & exMINUSONE(void);
ex const & exHALF(void);
ex const & exMINUSHALF(void);

#define INLINE_EX_CONSTRUCTORS

/** Lightweight interface to GiNaC's symbolic objects. Basically all it does is
 *  to hold a pointer to the other objects, manage the reference counting and
 *  provide methods for manipulation of these objects. */
class ex
{
    friend class basic;

// member functions

    // default constructor, destructor, copy constructor assignment operator and helpers
public:
    ex()
#ifdef INLINE_EX_CONSTRUCTORS
    : bp(exZERO().bp)
        {
            GINAC_ASSERT(exZERO().bp!=0);
            GINAC_ASSERT(exZERO().bp->flags & status_flags::dynallocated);
            GINAC_ASSERT(bp!=0);
            ++bp->refcount;
        }
#else
;
#endif // def INLINE_EX_CONSTRUCTORS

    ~ex()
#ifdef INLINE_EX_CONSTRUCTORS
        {
            GINAC_ASSERT(bp!=0);
            GINAC_ASSERT(bp->flags & status_flags::dynallocated);
            if (--bp->refcount == 0) {
                delete bp;
            }
        }
#else
;
#endif // def INLINE_EX_CONSTRUCTORS
        
    ex(ex const & other)
#ifdef INLINE_EX_CONSTRUCTORS
    : bp(other.bp)
        {
            GINAC_ASSERT(bp!=0);
            GINAC_ASSERT((bp->flags) & status_flags::dynallocated);
            ++bp->refcount;
        }
#else
;
#endif // def INLINE_EX_CONSTRUCTORS
        
    ex const & operator=(ex const & other)
#ifdef INLINE_EX_CONSTRUCTORS
        {
            GINAC_ASSERT(bp!=0);
            GINAC_ASSERT(bp->flags & status_flags::dynallocated);
            GINAC_ASSERT(other.bp!=0);
            GINAC_ASSERT(other.bp->flags & status_flags::dynallocated);
            ++other.bp->refcount;
            basic * tmpbp=other.bp;
            if (--bp->refcount==0) {
                delete bp;
            }
            bp=tmpbp;
            return *this;
        }
#else
;
#endif // def INLINE_EX_CONSTRUCTORS

    // other constructors
public:
    ex(basic const & other)
#ifdef INLINE_EX_CONSTRUCTORS
    {
        construct_from_basic(other);
    }
#else
;
#endif // def INLINE_EX_CONSTRUCTORS
    
    ex(int const i);
    ex(unsigned int const i);
    ex(long const i);
    ex(unsigned long const i);
    ex(double const d);

    // functions overriding virtual functions from bases classes
    // none
    
    // new virtual functions which can be overridden by derived classes
    // none

    // non-virtual functions in this class
public:
    void swap(ex & other);
    void printraw(ostream & os) const;
    void printtree(ostream & os, unsigned indent=0) const;
    void print(ostream & os, unsigned upper_precedence=0) const;
    void printcsrc(ostream & os, unsigned type, const char *var_name) const;
    void dbgprint(void) const;
    void dbgprinttree(void) const;
    bool info(unsigned inf) const;
    int nops() const;
    ex expand(unsigned options=0) const;
    bool has(ex const & other) const;
    int degree(symbol const & s) const;
    int ldegree(symbol const & s) const;
    ex coeff(symbol const & s, int const n=1) const;
    ex lcoeff(symbol const & s) const { return coeff(s, degree(s)); }
    ex tcoeff(symbol const & s) const { return coeff(s, ldegree(s)); }
    ex numer(bool normalize = true) const;
    ex denom(bool normalize = true) const;
    ex unit(const symbol &x) const;
    ex content(const symbol &x) const;
    numeric integer_content(void) const;
    ex primpart(const symbol &x) const;
    ex primpart(const symbol &x, const ex &cont) const;
    ex normal(int level = 0) const;
    ex smod(const numeric &xi) const;
    numeric max_coefficient(void) const;
    ex collect(symbol const & s) const;
    ex eval(int level = 0) const;
    ex evalf(int level = 0) const;
    ex diff(symbol const & s, unsigned nth = 1) const;
    ex series(symbol const & s, ex const & point, int order = 6) const;
    ex subs(lst const & ls, lst const & lr) const;
    ex subs(ex const & e) const;
    exvector get_indices(void) const;
    ex simplify_ncmul(exvector const & v) const;
    ex operator[](ex const & index) const;
    ex operator[](int const i) const;
    ex op(int const i) const;
    ex & let_op(int const i);
    int compare(ex const & other) const
#ifdef INLINE_EX_CONSTRUCTORS
        {
            GINAC_ASSERT(bp!=0);
            GINAC_ASSERT(other.bp!=0);
            if (bp==other.bp) {
                // special case: both expression point to same basic, trivially equal
                return 0; 
            }
            return bp->compare(*other.bp);
        }
#else
;
#endif // def INLINE_EX_CONSTRUCTORS
    bool is_equal(ex const & other) const
#ifdef INLINE_EX_CONSTRUCTORS
        {
            GINAC_ASSERT(bp!=0);
            GINAC_ASSERT(other.bp!=0);
            if (bp==other.bp) {
                // special case: both expression point to same basic, trivially equal
                return true; 
            }
            return bp->is_equal(*other.bp);
        }
#else
;
#endif // def INLINE_EX_CONSTRUCTORS
    bool is_zero(void) const {return compare(exZERO()) == 0;};
        
    unsigned return_type(void) const;
    unsigned return_type_tinfo(void) const;
    unsigned gethash(void) const;

    ex exadd(ex const & rh) const;
    ex exmul(ex const & rh) const;
    ex exncmul(ex const & rh) const;
private:
    void construct_from_basic(basic const & other);
    void makewriteable();

// member variables

public:
    basic *bp;
};

// utility functions
inline bool are_ex_trivially_equal(const ex &e1, const ex &e2)
{
	return e1.bp == e2.bp;
}

// wrapper functions around member functions
inline int nops(ex const & thisex)
{ return thisex.nops(); }

inline ex expand(ex const & thisex, unsigned options = 0)
{ return thisex.expand(options); }

inline bool has(ex const & thisex, ex const & other)
{ return thisex.has(other); }

inline int degree(ex const & thisex, symbol const & s)
{ return thisex.degree(s); }

inline int ldegree(ex const & thisex, symbol const & s)
{ return thisex.ldegree(s); }

inline ex coeff(ex const & thisex, symbol const & s, int const n=1)
{ return thisex.coeff(s, n); }

inline ex numer(ex const & thisex, bool normalize = true)
{ return thisex.numer(normalize); }

inline ex denom(ex const & thisex, bool normalize = true)
{ return thisex.denom(normalize); }

inline ex normal(ex const & thisex, int level=0)
{ return thisex.normal(level); }

inline ex collect(ex const & thisex, symbol const & s)
{ return thisex.collect(s); }

inline ex eval(ex const & thisex, int level = 0)
{ return thisex.eval(level); }

inline ex evalf(ex const & thisex, int level = 0)
{ return thisex.evalf(level); }

inline ex diff(ex const & thisex, symbol const & s, unsigned nth = 1)
{ return thisex.diff(s, nth); }

inline ex subs(ex const & thisex, ex const & e)
{ return thisex.subs(e); }

inline ex subs(ex const & thisex, lst const & ls, lst const & lr)
{ return thisex.subs(ls, lr); }

inline void swap(ex & e1, ex & e2)
{ e1.swap(e2); }

} // namespace GiNaC

#endif // ndef __GINAC_EX_H__