]> www.ginac.de Git - ginac.git/blobdiff - ginac/expairseq.h
documentation update
[ginac.git] / ginac / expairseq.h
index d9d7bf0530ecf6f78ef294f90be03fba848e63d2..23534978401c240f2fa4e3096282ce529ba1ee91 100644 (file)
@@ -3,7 +3,7 @@
  *  Interface to sequences of expression pairs. */
 
 /*
- *  GiNaC Copyright (C) 1999-2000 Johannes Gutenberg University Mainz, Germany
+ *  GiNaC Copyright (C) 1999-2002 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
 
 #include <vector>
 #include <list>
-
 // CINT needs <algorithm> to work properly with <vector> and <list>
-//#include <algorithm>
+#include <algorithm>
 
-#include <ginac/expair.h>
+#include "expair.h"
 
-#ifndef NO_GINAC_NAMESPACE
 namespace GiNaC {
-#endif // ndef NO_GINAC_NAMESPACE
-
-//#define EXPAIRSEQ_USE_HASHTAB
-
-typedef vector<expair> epvector;
-typedef epvector::iterator epviter;
-
-inline void iter_swap(epvector::iterator it1, epvector::iterator it2)
-{
-    (*it1).rest.swap((*it2).rest);
-    (*it1).coeff.swap((*it2).coeff);
-}
 
-typedef epvector::iterator epp;
-typedef list<epp> epplist;
-typedef vector<epplist> epplistvector;
+/** Using hash tables can potentially enhance the asymptotic behaviour of
+ *  combining n terms into one large sum (or n terms into one large product)
+ *  from O(n*log(n)) to about O(n).  There are, however, several drawbacks.
+ *  The constant in front of O(n) is quite large, when copying such an object
+ *  one also has to copy the has table, comparison is quite expensive because
+ *  there is no ordering any more, it doesn't help at all when combining two
+ *  expairseqs because due to the presorted nature the behaviour would be
+ *  O(n) anyways, the code is quite messy, etc, etc.  The code is here as
+ *  an example for following generations to tinker with. */
+#define EXPAIRSEQ_USE_HASHTAB 0
+
+typedef std::vector<expair> epvector;       ///< expair-vector
+typedef epvector::iterator epp;             ///< expair-vector pointer
+typedef std::list<epp> epplist;             ///< list of expair-vector pointers
+typedef std::vector<epplist> epplistvector; ///< vector of epplist
 
 /** A sequence of class expair.
  *  This is used for time-critical classes like sums and products of terms
  *  since handling a list of coeff and rest is much faster than handling a
- *  list of products or powers, respectively. (Incidentally, Maple does it
- *  the same way.) */
+ *  list of products or powers, respectively. (Not incidentally, Maple does it
+ *  the same way, maybe others too.)  The semantics is (at least) twofold:
+ *  one for addition and one for multiplication and several methods have to
+ *  be overridden by derived classes to reflect the change in semantics.
+ *  However, most functionality turns out to be shared between addition and
+ *  multiplication, which is the reason why there is this base class. */
 class expairseq : public basic
 {
-    GINAC_DECLARE_REGISTERED_CLASS(expairseq, basic)
+       GINAC_DECLARE_REGISTERED_CLASS_NO_CTORS(expairseq, basic)
 
 // member functions
 
-    // default constructor, destructor, copy constructor assignment operator and helpers
+       // default ctor, dtor, copy ctor, assignment operator and helpers
 public:
-    expairseq() : basic(TINFO_expairseq)
-#ifdef EXPAIRSEQ_USE_HASHTAB
-        , hashtabsize(0)
-#endif // def EXPAIRSEQ_USE_HASHTAB
-        {
-        }
-    ~expairseq()
-        {
-            destroy(0);
-        }
-    expairseq(expairseq const & other);
-    expairseq const & operator=(expairseq const & other);
+       expairseq() : basic(TINFO_expairseq)
+#if EXPAIRSEQ_USE_HASHTAB
+                                           , hashtabsize(0)
+#endif // EXPAIRSEQ_USE_HASHTAB
+       { }
+       ~expairseq() { destroy(false); }
+       expairseq(const expairseq & other);
+       const expairseq & operator=(const expairseq & other);
 protected:
-    void copy(expairseq const & other);
-    void destroy(bool call_parent)
-        {
-            if (call_parent) basic::destroy(call_parent);
-        };
-
-    // other constructors
+       void copy(const expairseq & other);
+       void destroy(bool call_parent);
+       // other ctors
 public:
-    expairseq(ex const & lh, ex const & rh);
-    expairseq(exvector const & v);
-    expairseq(epvector const & v, ex const & oc);
-    expairseq(epvector * vp, ex const & oc); // vp will be deleted
-
-    // functions overriding virtual functions from bases classes
+       expairseq(const ex & lh, const ex & rh);
+       expairseq(const exvector & v);
+       expairseq(const epvector & v, const ex & oc);
+       expairseq(epvector * vp, const ex & oc); // vp will be deleted
+       
+       // 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;
-    void printtree(ostream & os, unsigned indent) const;
-    bool info(unsigned inf) const;
-    unsigned nops() const;
-    ex op(int const i) const;
-    ex & let_op(int const i);
-    ex eval(int level=0) const;
-    ex evalf(int level=0) const;
-    ex normal(lst &sym_lst, lst &repl_lst, int level=0) const;
-    ex diff(symbol const & s) const;
-    ex subs(lst const & ls, lst const & lr) const;
+       basic * duplicate() const;
+       void print(const print_context & c, unsigned level = 0) const;
+       unsigned precedence(void) const {return 10;}
+       bool info(unsigned inf) const;
+       unsigned nops() const;
+       ex op(int i) const;
+       ex & let_op(int i);
+       ex map(map_function & f) const;
+       ex eval(int level=0) const;
+       ex to_rational(lst &repl_lst) const;
+       bool match(const ex & pattern, lst & repl_lst) const;
+       ex subs(const lst & ls, const lst & lr, bool no_pattern = false) const;
 protected:
-    int compare_same_type(basic const & other) const;
-    bool is_equal_same_type(basic const & other) const;
-    unsigned return_type(void) const;
-    unsigned calchash(void) const;
-    ex expand(unsigned options=0) const;
-
-    // new virtual functions which can be overridden by derived classes
+       int compare_same_type(const basic & other) const;
+       bool is_equal_same_type(const basic & other) const;
+       unsigned return_type(void) const;
+       unsigned calchash(void) const;
+       ex expand(unsigned options=0) const;
+       
+       // new virtual functions which can be overridden by derived classes
 protected:
-    virtual ex thisexpairseq(epvector const & v, ex const & oc) const;
-    virtual ex thisexpairseq(epvector * vp, ex const & oc) const;
-    virtual void printseq(ostream & os, char delim, unsigned this_precedence,
-                          unsigned upper_precedence) const;
-    virtual void printpair(ostream & os, expair const & p,
-                           unsigned upper_precedence) const;
-    virtual expair split_ex_to_pair(ex const & e) const;
-    virtual expair combine_ex_with_coeff_to_pair(ex const & e,
-                                                 ex const & c) const;
-    virtual expair combine_pair_with_coeff_to_pair(expair const & p,
-                                                   ex const & c) const;
-    virtual ex recombine_pair_to_ex(expair const & p) const;
-    virtual bool expair_needs_further_processing(epp it);
-    virtual ex default_overall_coeff(void) const;
-    virtual void combine_overall_coeff(ex const & c);
-    virtual void combine_overall_coeff(ex const & c1, ex const & c2);
-    virtual bool can_make_flat(expair const & p) const;
-    
-    // non-virtual functions in this class
+       virtual ex thisexpairseq(const epvector & v, const ex & oc) const;
+       virtual ex thisexpairseq(epvector * vp, const ex & oc) const;
+       virtual void printseq(const print_context & c, char delim,
+                             unsigned this_precedence,
+                             unsigned upper_precedence) const;
+       virtual void printpair(const print_context & c, const expair & p,
+                              unsigned upper_precedence) const;
+       virtual expair split_ex_to_pair(const ex & e) const;
+       virtual expair combine_ex_with_coeff_to_pair(const ex & e,
+                                                                                                const ex & c) const;
+       virtual expair combine_pair_with_coeff_to_pair(const expair & p,
+                                                                                                  const ex & c) const;
+       virtual ex recombine_pair_to_ex(const expair & p) const;
+       virtual bool expair_needs_further_processing(epp it);
+       virtual ex default_overall_coeff(void) const;
+       virtual void combine_overall_coeff(const ex & c);
+       virtual void combine_overall_coeff(const ex & c1, const ex & c2);
+       virtual bool can_make_flat(const expair & p) const;
+       
+       // non-virtual functions in this class
 protected:
-    void construct_from_2_ex_via_exvector(ex const & lh, ex const & rh);
-    void construct_from_2_ex(ex const & lh, ex const & rh);
-    void construct_from_2_expairseq(expairseq const & s1,
-                                    expairseq const & s2);
-    void construct_from_expairseq_ex(expairseq const & s,
-                                     ex const & e);
-    void construct_from_exvector(exvector const & v);
-    void construct_from_epvector(epvector const & v);
-    void make_flat(exvector const & v);
-    void make_flat(epvector const & v);
-    epvector * bubblesort(epvector::iterator itbegin, epvector::iterator itend);
-    epvector * mergesort(epvector::iterator itbegin, epvector::iterator itend);
-    void canonicalize(void);
-    void combine_same_terms_sorted_seq(void);
-#ifdef EXPAIRSEQ_USE_HASHTAB
-    void combine_same_terms(void);
-    unsigned calc_hashtabsize(unsigned sz) const;
-    unsigned calc_hashindex(ex const & e) const;
-    void shrink_hashtab(void);
-    void remove_hashtab_entry(epvector::const_iterator element);
-    void move_hashtab_entry(epvector::const_iterator oldpos,
-                            epvector::iterator newpos);
-    void sorted_insert(epplist & eppl, epp elem);
-    void build_hashtab_and_combine(epvector::iterator & first_numeric,
-                                   epvector::iterator & last_non_zero,
-                                   vector<bool> & touched,
-                                   unsigned & number_of_zeroes);
-    void drop_coeff_0_terms(epvector::iterator & first_numeric,
-                            epvector::iterator & last_non_zero,
-                            vector<bool> & touched,
-                            unsigned & number_of_zeroes);
-    bool has_coeff_0(void) const;
-    void add_numerics_to_hashtab(epvector::iterator first_numeric,                                              epvector::const_iterator last_non_zero);
-#endif // def EXPAIRSEQ_USE_HASHTAB
-    bool is_canonical() const;
-    epvector * expandchildren(unsigned options) const;
-    epvector * evalchildren(int level) const;
-    epvector evalfchildren(int level) const;
-    epvector normalchildren(int level) const;
-    epvector diffchildren(symbol const & s) const;
-    epvector * subschildren(lst const & ls, lst const & lr) const;
-    
+       void construct_from_2_ex_via_exvector(const ex & lh, const ex & rh);
+       void construct_from_2_ex(const ex & lh, const ex & rh);
+       void construct_from_2_expairseq(const expairseq & s1,
+                                       const expairseq & s2);
+       void construct_from_expairseq_ex(const expairseq & s,
+                                        const ex & e);
+       void construct_from_exvector(const exvector & v);
+       void construct_from_epvector(const epvector & v);
+       void make_flat(const exvector & v);
+       void make_flat(const epvector & v);
+       void canonicalize(void);
+       void combine_same_terms_sorted_seq(void);
+#if EXPAIRSEQ_USE_HASHTAB
+       void combine_same_terms(void);
+       unsigned calc_hashtabsize(unsigned sz) const;
+       unsigned calc_hashindex(const ex & e) const;
+       void shrink_hashtab(void);
+       void remove_hashtab_entry(epvector::const_iterator element);
+       void move_hashtab_entry(epvector::const_iterator oldpos,
+                               epvector::iterator newpos);
+       void sorted_insert(epplist & eppl, epvector::const_iterator elem);
+       void build_hashtab_and_combine(epvector::iterator & first_numeric,
+                                      epvector::iterator & last_non_zero,
+                                      vector<bool> & touched,
+                                      unsigned & number_of_zeroes);
+       void drop_coeff_0_terms(epvector::iterator & first_numeric,
+                               epvector::iterator & last_non_zero,
+                               vector<bool> & touched,
+                               unsigned & number_of_zeroes);
+       bool has_coeff_0(void) const;
+       void add_numerics_to_hashtab(epvector::iterator first_numeric,
+                                    epvector::const_iterator last_non_zero);
+#endif // EXPAIRSEQ_USE_HASHTAB
+       bool is_canonical() const;
+       epvector * expandchildren(unsigned options) const;
+       epvector * evalchildren(int level) const;
+       epvector * subschildren(const lst & ls, const lst & lr, bool no_pattern = false) const;
+       
 // member variables
-    
+       
 protected:
-    epvector seq;
-    ex overall_coeff;
-    static unsigned precedence;
-#ifdef EXPAIRSEQ_USE_HASHTAB
-    epplistvector hashtab;
-    unsigned hashtabsize;
-    unsigned hashmask;
-    static unsigned maxhashtabsize;
-    static unsigned minhashtabsize;
-    static unsigned hashtabfactor;
-#endif // def EXPAIRSEQ_USE_HASHTAB
+       epvector seq;
+       ex overall_coeff;
+#if EXPAIRSEQ_USE_HASHTAB
+       epplistvector hashtab;
+       unsigned hashtabsize;
+       unsigned hashmask;
+       static unsigned maxhashtabsize;
+       static unsigned minhashtabsize;
+       static unsigned hashtabfactor;
+#endif // EXPAIRSEQ_USE_HASHTAB
 };
 
-// global constants
-
-extern const expairseq some_expairseq;
-extern type_info const & typeid_expairseq;
-
 // utility functions
-inline const expairseq &ex_to_expairseq(const ex &e)
+
+/** Specialization of is_exactly_a<expairseq>(obj) for expairseq objects. */
+template<> inline bool is_exactly_a<expairseq>(const basic & obj)
 {
-       return static_cast<const expairseq &>(*e.bp);
+       return obj.tinfo()==TINFO_expairseq;
 }
 
-#ifndef NO_GINAC_NAMESPACE
 } // namespace GiNaC
-#endif // ndef NO_GINAC_NAMESPACE
 
 #endif // ndef __GINAC_EXPAIRSEQ_H__