X-Git-Url: https://www.ginac.de/ginac.git//ginac.git?p=ginac.git;a=blobdiff_plain;f=ginac%2Fexpairseq.h;h=e4e34653f33ff273774aa91937a5fb1cbdda5a0c;hp=ee7ddbd3fcc358d5f03e7b0167a9275fb2eb7604;hb=94c15f8b02a5a9e274d3aedcefd76565861b4219;hpb=19c8f943c15dcc0d946fb4d5fef11e487d34857a diff --git a/ginac/expairseq.h b/ginac/expairseq.h index ee7ddbd3..e4e34653 100644 --- a/ginac/expairseq.h +++ b/ginac/expairseq.h @@ -3,7 +3,7 @@ * Interface to sequences of expression pairs. */ /* - * GiNaC Copyright (C) 1999-2000 Johannes Gutenberg University Mainz, Germany + * GiNaC Copyright (C) 1999-2001 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 @@ -25,76 +25,69 @@ #include #include - // CINT needs to work properly with and #include #include "expair.h" -#ifndef NO_NAMESPACE_GINAC namespace GiNaC { -#endif // ndef NO_NAMESPACE_GINAC - -//#define EXPAIRSEQ_USE_HASHTAB -typedef std::vector 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 std::list epplist; -typedef std::vector 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 epvector; ///< expair-vector +typedef epvector::iterator epviter; ///< expair-vector iterator +typedef epvector::iterator epp; ///< expair-vector pointer +typedef std::list epplist; ///< list of expair-vector pointers +typedef std::vector 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 +#if EXPAIRSEQ_USE_HASHTAB , hashtabsize(0) -#endif // def EXPAIRSEQ_USE_HASHTAB - { - } - ~expairseq() - { - destroy(0); - } +#endif // EXPAIRSEQ_USE_HASHTAB + { } + ~expairseq() { destroy(false); } expairseq(const expairseq & other); const expairseq & operator=(const expairseq & other); protected: void copy(const expairseq & other); - void destroy(bool call_parent) - { - if (call_parent) basic::destroy(call_parent); - }; - - // other constructors + void destroy(bool call_parent); + // other ctors public: 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 bases classes public: basic * duplicate() const; - void print(std::ostream & os, unsigned upper_precedence=0) const; - void printraw(std::ostream & os) const; - void printtree(std::ostream & os, unsigned indent) const; + void print(const print_context & c, unsigned level = 0) const; bool info(unsigned inf) const; unsigned nops() const; ex op(int i) const; @@ -111,15 +104,15 @@ protected: 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(const epvector & v, const ex & oc) const; virtual ex thisexpairseq(epvector * vp, const ex & oc) const; - virtual void printseq(std::ostream & os, char delim, + virtual void printseq(const print_context & c, char delim, unsigned this_precedence, unsigned upper_precedence) const; - virtual void printpair(std::ostream & os, const expair & p, + 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, @@ -145,11 +138,9 @@ protected: void construct_from_epvector(const epvector & v); void make_flat(const exvector & v); void make_flat(const epvector & 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 +#if EXPAIRSEQ_USE_HASHTAB void combine_same_terms(void); unsigned calc_hashtabsize(unsigned sz) const; unsigned calc_hashindex(const ex & e) const; @@ -169,7 +160,7 @@ protected: 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 +#endif // EXPAIRSEQ_USE_HASHTAB bool is_canonical() const; epvector * expandchildren(unsigned options) const; epvector * evalchildren(int level) const; @@ -184,29 +175,22 @@ protected: epvector seq; ex overall_coeff; static unsigned precedence; -#ifdef EXPAIRSEQ_USE_HASHTAB +#if EXPAIRSEQ_USE_HASHTAB epplistvector hashtab; unsigned hashtabsize; unsigned hashmask; static unsigned maxhashtabsize; static unsigned minhashtabsize; static unsigned hashtabfactor; -#endif // def EXPAIRSEQ_USE_HASHTAB +#endif // EXPAIRSEQ_USE_HASHTAB }; -// global constants - -extern const expairseq some_expairseq; -extern const type_info & typeid_expairseq; - // utility functions inline const expairseq &ex_to_expairseq(const ex &e) { return static_cast(*e.bp); } -#ifndef NO_NAMESPACE_GINAC } // namespace GiNaC -#endif // ndef NO_NAMESPACE_GINAC #endif // ndef __GINAC_EXPAIRSEQ_H__