container.h

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/*
 *  GiNaC Copyright (C) 1999-2026 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, see <https://www.gnu.org/licenses/>.
 */
 
#ifndef GINAC_CONTAINER_H
#define GINAC_CONTAINER_H
 
#include "ex.h"
#include "print.h"
#include "archive.h"
#include "assertion.h"
#include "compiler.h"
 
#include <algorithm>
#include <iterator>
#include <list>
#include <memory>
#include <stdexcept>
#include <vector>
 
namespace GiNaC {
 
template <template <class T, class = std::allocator<T>> class C>
class container_storage {
protected:
    typedef C<ex> STLT;
 
    container_storage() {}
    container_storage(size_t n, const ex & e) : seq(n, e) {}
    container_storage(std::initializer_list<ex> il) : seq(il) {}
 
    template <class In>
    container_storage(In b, In e) : seq(b, e) {}
 
    void reserve(size_t) {}
    static void reserve(STLT &, size_t) {}
 
    STLT seq;
 
    // disallow destruction of container through a container_storage*
protected:
    ~container_storage() {}
};
 
template <>
inline void container_storage<std::vector>::reserve(size_t n) { seq.reserve(n); }
 
template <>
inline void container_storage<std::vector>::reserve(std::vector<ex> & v, size_t n) { v.reserve(n); }
 
 
template <template <class T, class = std::allocator<T>> class C>
class container : public basic, public container_storage<C> {
    GINAC_DECLARE_REGISTERED_CLASS(container, basic)
protected:
    typedef typename container_storage<C>::STLT STLT;
 
public:
    typedef typename STLT::const_iterator const_iterator;
    typedef typename STLT::const_reverse_iterator const_reverse_iterator;
 
protected:
    // helpers
    static unsigned get_default_flags() { return 0; }
    static char get_open_delim() { return '('; }
    static char get_close_delim() { return ')'; }
 
    // constructors
public:
    container(STLT const & s)
    {
        setflag(get_default_flags());
        this->seq = s;
    }
 
    explicit container(STLT && v)
    {
        setflag(get_default_flags());
        this->seq.swap(v);
    }
 
    container(exvector::const_iterator b, exvector::const_iterator e)
     : container_storage<C>(b, e)
    {
        setflag(get_default_flags());
    }
 
    container(std::initializer_list<ex> il)
     : container_storage<C>(il)
    {
        setflag(get_default_flags());
    }
 
    // functions overriding virtual functions from base classes
public:
    bool info(unsigned inf) const override { return inherited::info(inf); }
    unsigned precedence() const override { return 10; }
    size_t nops() const override { return this->seq.size(); }
    ex op(size_t i) const override;
    ex & let_op(size_t i) override;
    ex subs(const exmap & m, unsigned options = 0) const override;
 
    void read_archive(const archive_node &n, lst &sym_lst) override
    {
        inherited::read_archive(n, sym_lst);
        setflag(get_default_flags());
 
        auto range =  n.find_property_range("seq", "seq");
        this->reserve(this->seq, range.end - range.begin);
        for (archive_node::archive_node_cit i=range.begin; i<range.end; ++i) {
            ex e;
            n.find_ex_by_loc(i, e, sym_lst);
            this->seq.emplace_back(e);
        }
    }
 
    void archive(archive_node &n) const override
    {
        inherited::archive(n);
        for (auto & i : this->seq) {
            n.add_ex("seq", i);
        }
    }
 
protected:
    ex conjugate() const override
    {
        STLT *newcont = nullptr;
        for (const_iterator i=this->seq.begin(); i!=this->seq.end(); ++i) {
            if (newcont) {
                newcont->push_back(i->conjugate());
                continue;
            }
            ex x = i->conjugate();
            if (are_ex_trivially_equal(x, *i)) {
                continue;
            }
            newcont = new STLT;
            this->reserve(*newcont, this->seq.size());
            for (const_iterator j=this->seq.begin(); j!=i; ++j) {
                newcont->push_back(*j);
            }
            newcont->push_back(x);
        }
        if (newcont) {
            ex result = thiscontainer(*newcont);
            delete newcont;
            return result;
        }
        return *this;
    }
 
    ex real_part() const override
    {
        STLT cont;
        this->reserve(cont, nops());
        const_iterator b = begin();
        const_iterator e = end();
        for(const_iterator i=b; i!=e; ++i)
            cont.push_back(i->real_part());
        return thiscontainer(cont);
    }
 
    ex imag_part() const override
    {
        STLT cont;
        this->reserve(cont, nops());
        const_iterator b = begin();
        const_iterator e = end();
        for(const_iterator i=b; i!=e; ++i)
            cont.push_back(i->imag_part());
        return thiscontainer(cont);
    }
 
    bool is_equal_same_type(const basic & other) const override;
 
    // new virtual functions which can be overridden by derived classes
protected:
    virtual ex thiscontainer(const STLT & v) const { return container(v); }
 
    virtual ex thiscontainer(STLT && v) const { return container(std::move(v)); }
 
    virtual void printseq(const print_context & c, char openbracket, char delim,
                          char closebracket, unsigned this_precedence,
                          unsigned upper_precedence = 0) const;
 
    // non-virtual functions in this class
private:
    void sort_(std::random_access_iterator_tag)
    {
        std::sort(this->seq.begin(), this->seq.end(), ex_is_less());
    }
 
    void sort_(std::input_iterator_tag)
    {
        this->seq.sort(ex_is_less());
    }
 
    void unique_()
    {
        typename STLT::iterator p = std::unique(this->seq.begin(), this->seq.end(), ex_is_equal());
        this->seq.erase(p, this->seq.end());
    }
 
public:
    container & prepend(const ex & b);
    container & append(const ex & b);
    container & remove_first();
    container & remove_last();
    container & remove_all();
    container & sort();
    container & unique();
 
    const_iterator begin() const {return this->seq.begin();}
    const_iterator end() const {return this->seq.end();}
    const_reverse_iterator rbegin() const {return this->seq.rbegin();}
    const_reverse_iterator rend() const {return this->seq.rend();}
 
protected:
    void do_print(const print_context & c, unsigned level) const;
    void do_print_tree(const print_tree & c, unsigned level) const;
    void do_print_python(const print_python & c, unsigned level) const;
    void do_print_python_repr(const print_python_repr & c, unsigned level) const;
    STLT subschildren(const exmap & m, unsigned options = 0) const;
};
 
template <template <class T, class = std::allocator<T>> class C>
container<C>::container()
{
    setflag(get_default_flags());
}
 
template <template <class T, class = std::allocator<T>> class C>
void container<C>::do_print(const print_context & c, unsigned level) const
{
    // always print brackets around seq, ignore upper_precedence
    printseq(c, get_open_delim(), ',', get_close_delim(), precedence(), precedence()+1);
}
 
template <template <class T, class = std::allocator<T>> class C>
void container<C>::do_print_tree(const print_tree & c, unsigned level) const
{
    c.s << std::string(level, ' ') << class_name() << " @" << this
        << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
        << ", nops=" << nops()
        << std::endl;
    const_iterator i = this->seq.begin(), end = this->seq.end();
    while (i != end) {
        i->print(c, level + c.delta_indent);
        ++i;
    }
    c.s << std::string(level + c.delta_indent,' ') << "=====" << std::endl;
}
 
template <template <class T, class = std::allocator<T>> class C>
void container<C>::do_print_python(const print_python & c, unsigned level) const
{
    printseq(c, '[', ',', ']', precedence(), precedence()+1);
}
 
template <template <class T, class = std::allocator<T>> class C>
void container<C>::do_print_python_repr(const print_python_repr & c, unsigned level) const
{
    c.s << class_name();
    printseq(c, '(', ',', ')', precedence(), precedence()+1);
}
 
template <template <class T, class = std::allocator<T>> class C>
ex container<C>::op(size_t i) const
{
    GINAC_ASSERT(i < nops());
 
    const_iterator it = this->seq.begin();
    advance(it, i);
    return *it;
}
 
template <template <class T, class = std::allocator<T>> class C>
ex & container<C>::let_op(size_t i)
{
    GINAC_ASSERT(i < nops());
 
    ensure_if_modifiable();
    typename STLT::iterator it = this->seq.begin();
    advance(it, i);
    return *it;
}
 
template <template <class T, class = std::allocator<T>> class C>
ex container<C>::subs(const exmap & m, unsigned options) const
{
    // After having subs'ed all children, this method subs'es one final
    // level, but only if the intermediate result is a container! This is
    // because if the intermediate result has eval'ed to a non-container a
    // last level substitution would be wrong, as this example involving a
    // function f and its inverse f^-1 shows:
    // f(x).subs(x==f^-1(x))
    //   -> f(f^-1(x))  [subschildren]
    //   -> x           [eval]   /* must not subs(x==f^-1(x))! */
    STLT subsed = subschildren(m, options);
    if (!subsed.empty()) {
        ex result(thiscontainer(subsed));
        if (is_a<container<C>>(result))
            return ex_to<basic>(result).subs_one_level(m, options);
        else
            return result;
    } else {
        if (is_a<container<C>>(*this))
            return subs_one_level(m, options);
        else
            return *this;
    }
}
 
template <template <class T, class = std::allocator<T>> class C>
int container<C>::compare_same_type(const basic & other) const
{
    GINAC_ASSERT(is_a<container>(other));
    const container & o = static_cast<const container &>(other);
 
    const_iterator it1 = this->seq.begin(), it1end = this->seq.end(),
                   it2 = o.seq.begin(), it2end = o.seq.end();
 
    while (it1 != it1end && it2 != it2end) {
        int cmpval = it1->compare(*it2);
        if (cmpval)
            return cmpval;
        ++it1; ++it2;
    }
 
    return (it1 == it1end) ? (it2 == it2end ? 0 : -1) : 1;
}
 
template <template <class T, class = std::allocator<T>> class C>
bool container<C>::is_equal_same_type(const basic & other) const
{
    GINAC_ASSERT(is_a<container>(other));
    const container & o = static_cast<const container &>(other);
 
    if (this->seq.size() != o.seq.size())
        return false;
 
    const_iterator it1 = this->seq.begin(), it1end = this->seq.end(), it2 = o.seq.begin();
    while (it1 != it1end) {
        if (!it1->is_equal(*it2))
            return false;
        ++it1; ++it2;
    }
 
    return true;
}
 
template <template <class T, class = std::allocator<T>> class C>
container<C> & container<C>::prepend(const ex & b)
{
    ensure_if_modifiable();
    this->seq.push_front(b);
    return *this;
}
 
template <template <class T, class = std::allocator<T>> class C>
container<C> & container<C>::append(const ex & b)
{
    ensure_if_modifiable();
    this->seq.push_back(b);
    return *this;
}
 
template <template <class T, class = std::allocator<T>> class C>
container<C> & container<C>::remove_first()
{
    ensure_if_modifiable();
    this->seq.pop_front();
    return *this;
}
 
template <template <class T, class = std::allocator<T>> class C>
container<C> & container<C>::remove_last()
{
    ensure_if_modifiable();
    this->seq.pop_back();
    return *this;
}
 
template <template <class T, class = std::allocator<T>> class C>
container<C> & container<C>::remove_all()
{
    ensure_if_modifiable();
    this->seq.clear();
    return *this;
}
 
template <template <class T, class = std::allocator<T>> class C>
container<C> & container<C>::sort()
{
    ensure_if_modifiable();
    sort_(typename std::iterator_traits<typename STLT::iterator>::iterator_category());
    return *this;
}
 
template<> inline void container<std::list>::unique_()
{
    this->seq.unique(ex_is_equal());
}
 
template <template <class T, class = std::allocator<T>> class C>
container<C> & container<C>::unique()
{
    ensure_if_modifiable();
    unique_();
    return *this;
}
 
template <template <class T, class = std::allocator<T>> class C>
void container<C>::printseq(const print_context & c, char openbracket, char delim,
                            char closebracket, unsigned this_precedence,
                            unsigned upper_precedence) const
{
    if (this_precedence <= upper_precedence)
        c.s << openbracket;
 
    if (!this->seq.empty()) {
        const_iterator it = this->seq.begin(), itend = this->seq.end();
        --itend;
        while (it != itend) {
            it->print(c, this_precedence);
            c.s << delim;
            ++it;
        }
        it->print(c, this_precedence);
    }
 
    if (this_precedence <= upper_precedence)
        c.s << closebracket;
}
 
template <template <class T, class = std::allocator<T>> class C>
typename container<C>::STLT container<C>::subschildren(const exmap & m, unsigned options) const
{
    // returns an empty container if nothing had to be substituted
    // returns a STLT with substituted elements otherwise
 
    const_iterator cit = this->seq.begin(), end = this->seq.end();
    while (cit != end) {
        const ex & subsed_ex = cit->subs(m, options);
        if (!are_ex_trivially_equal(*cit, subsed_ex)) {
 
            // copy first part of seq which hasn't changed
            STLT s(this->seq.begin(), cit);
            this->reserve(s, this->seq.size());
 
            // insert changed element
            s.push_back(subsed_ex);
            ++cit;
 
            // copy rest
            while (cit != end) {
                s.push_back(cit->subs(m, options));
                ++cit;
            }
 
            return s;
        }
 
        ++cit;
    }
    
    return STLT(); // nothing has changed
}
 
} // namespace GiNaC
 
#endif // ndef GINAC_CONTAINER_H