constant.cpp

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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/>.
 */
 
#include "constant.h"
#include "numeric.h"
#include "ex.h"
#include "archive.h"
#include "utils.h"
#include "inifcns.h"
 
#include <stdexcept>
#include <string>
 
namespace GiNaC {
 
GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(constant, basic,
  print_func<print_context>(&constant::do_print).
  print_func<print_latex>(&constant::do_print_latex).
  print_func<print_tree>(&constant::do_print_tree).
  print_func<print_python_repr>(&constant::do_print_python_repr))
 
 
// default constructor
 
// public
 
constant::constant() : ef(nullptr), serial(next_serial++), domain(domain::complex)
{
    setflag(status_flags::evaluated | status_flags::expanded);
}
 
// other constructors
 
// public
 
constant::constant(const std::string & initname, evalffunctype efun, const std::string & texname, unsigned dm)
  : name(initname), ef(efun), serial(next_serial++), domain(dm)
{
    if (texname.empty())
        TeX_name = "\\mathrm{" + name + "}";
    else
        TeX_name = texname;
    setflag(status_flags::evaluated | status_flags::expanded);
}
 
constant::constant(const std::string & initname, const numeric & initnumber, const std::string & texname, unsigned dm)
  : name(initname), ef(nullptr), number(initnumber), serial(next_serial++), domain(dm)
{
    if (texname.empty())
        TeX_name = "\\mathrm{" + name + "}";
    else
        TeX_name = texname;
    setflag(status_flags::evaluated | status_flags::expanded);
}
 
// archiving
 
void constant::read_archive(const archive_node &n, lst &sym_lst)
{
    // Find constant by name (!! this is bad: 'twould be better if there
    // was a list of all global constants that we could search)
    std::string s;
    if (n.find_string("name", s)) {
        if (s == Pi.name)
            *this = Pi;
        else if (s == Catalan.name)
            *this = Catalan;
        else if (s == Euler.name)
            *this = Euler;
        else
            throw (std::runtime_error("unknown constant '" + s + "' in archive"));
    } else
        throw (std::runtime_error("unnamed constant in archive"));
}
GINAC_BIND_UNARCHIVER(constant);
 
void constant::archive(archive_node &n) const
{
    inherited::archive(n);
    n.add_string("name", name);
}
 
// functions overriding virtual functions from base classes
 
// public
 
void constant::do_print(const print_context & c, unsigned level) const
{
    c.s << name;
}
 
void constant::do_print_tree(const print_tree & c, unsigned level) const
{
    c.s << std::string(level, ' ') << name << " (" << class_name() << ")" << " @" << this
        << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
        << std::endl;
}
 
void constant::do_print_latex(const print_latex & c, unsigned level) const
{
    c.s << TeX_name;
}
 
void constant::do_print_python_repr(const print_python_repr & c, unsigned level) const
{
    c.s << class_name() << "('" << name << "'";
    if (TeX_name != "\\mathrm{" + name + "}")
        c.s << ",TeX_name='" << TeX_name << "'";
    c.s << ')';
}
 
bool constant::info(unsigned inf) const
{
    if (inf == info_flags::polynomial)
        return true;
    if (inf == info_flags::real)
        return domain==domain::real || domain==domain::positive ;
    if (inf==info_flags::positive || inf==info_flags::nonnegative)
        return domain == domain::positive;
    else
        return inherited::info(inf);
}
 
ex constant::evalf() const
{
    if (ef!=nullptr) {
        return ef();
    } else {
        return number.evalf();
    }
    return *this;
}
 
bool constant::is_polynomial(const ex & var) const
{
    return true;
}
 
ex constant::conjugate() const
{
    if ( domain==domain::real || domain==domain::positive )
        return *this;
    return conjugate_function(*this).hold();
}
 
ex constant::real_part() const
{
    if ( domain==domain::real || domain==domain::positive )
        return *this;
    return real_part_function(*this).hold();
}
 
ex constant::imag_part() const
{
    if ( domain==domain::real || domain==domain::positive )
        return 0;
    return imag_part_function(*this).hold();
}
 
// protected
 
ex constant::derivative(const symbol & s) const
{
    return _ex0;
}
 
int constant::compare_same_type(const basic & other) const
{
    GINAC_ASSERT(is_exactly_a<constant>(other));
    const constant &o = static_cast<const constant &>(other);
 
    if (serial == o.serial)
        return 0;
    else
        return serial < o.serial ? -1 : 1;
}
 
bool constant::is_equal_same_type(const basic & other) const
{
    GINAC_ASSERT(is_exactly_a<constant>(other));
    const constant &o = static_cast<const constant &>(other);
 
    return serial == o.serial;
}
 
unsigned constant::calchash() const
{
    const void* typeid_this = (const void*)typeid(*this).name();
    hashvalue = golden_ratio_hash((uintptr_t)typeid_this ^ serial);
 
    setflag(status_flags::hash_calculated);
 
    return hashvalue;
}
 
// new virtual functions which can be overridden by derived classes
 
// none
 
// non-virtual functions in this class
 
// none
 
// static member variables
 
unsigned constant::next_serial = 0;
 
// global constants
 
const constant Pi("Pi", PiEvalf, "\\pi", domain::positive);
 
const constant Euler("Euler", EulerEvalf, "\\gamma_E", domain::positive);
 
const constant Catalan("Catalan", CatalanEvalf, "G", domain::positive);
 
} // namespace GiNaC