pmax.hh

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// This file is part of Awali.
// Copyright 2016-2022 Sylvain Lombardy, Victor Marsault, Jacques Sakarovitch
//
// Awali is a 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 3 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 <http://www.gnu.org/licenses/>.
 
#ifndef AWALI_WEIGHTSET_PMAX_HH
# define AWALI_WEIGHTSET_PMAX_HH
 
# include <ostream>
# include <string>
# include <sstream>
# include <utility>
 
#include <awali/sttc/misc/raise.hh>
#include <awali/common/enums.hh>
#include <awali/sttc/misc/stream.hh> // eat
#include <awali/sttc/weightset/fwd.hh>
#include <awali/sttc/weightset/b.hh>
#include <awali/sttc/weightset/weightset.hh>
 
namespace awali {
  namespace sttc {
  class pmax
  {
  public:
    using self_type = pmax;
 
    static std::string sname()
    {
      return "pmax";
    }
 
    std::string vname(bool = true) const
    {
      return sname();
    }
 
    static pmax make(std::istream& is)
    {
      eat(is, sname());
      return {};
    }
 
    using value_t = double;
 
    static value_t
    add(const value_t l, const value_t r)
    {
      return std::max(l, r);
    }
 
    static value_t
    mul(const value_t l, const value_t r)
    {
      return l*r;
    }
 
    static value_t
    rdiv(const value_t l, const value_t r)
    {
      require(!is_zero(r), "div: division by zero");
      return l/r;
    }
 
    static value_t
    ldiv(const value_t l, const value_t r)
    {
      return rdiv(r, l);
    }
 
    value_t
    star(const value_t v) const
    {
      if (v <= 1)
        return one();
      else
        raise(sname(), ": star: invalid value: ", format(*this, v));
    }
 
    static value_t
    one()
    {
      return 1.0;
    }
 
    static value_t
    zero()
    {
      return 0.0;
    }
 
    static bool
    equals(const value_t l, const value_t r)
    {
      return l == r;
    }
 
    static bool less_than(value_t lhs, value_t rhs)
    {
      return lhs < rhs;
    }
 
    constexpr static bool is_special(value_t)
    {
      return false;
    }
 
    static bool
    is_zero(const value_t v)
    {
      return v == zero();
    }
 
    static bool
    is_one(const value_t v)
    {
      return v == one();
    }
 
    static constexpr bool is_commutative_semiring() { return true; }
 
    static constexpr bool show_one() { return false; }
    static constexpr star_status_t star_status() { return star_status_t::TOPS; }
 
    static value_t
    transpose(const value_t v)
    {
      return v;
    }
 
    static size_t hash(value_t v)
    {
      return utils::hash_value(v);
    }
 
    static value_t
    conv(self_type, value_t v)
    {
      return v;
    }
 
    static value_t
    conv(b, b::value_t v)
    {
      return v ? one() : zero();
    }
 
    static value_t
    conv(std::istream& i)
    {
      value_t res;
      if (i >> res) {
        if(res<0)
          sttc::fail_reading(i, sname() + ": invalid value");
        return res;
      }
      else
        sttc::fail_reading(i, sname() + ": invalid value");
    }
 
    static value_t
    parse(const std::string & s, size_t& p) {
      size_t i=p;
      for(; i>0 && ((s[i-1]>='0' && s[i-1]<='9') || s[i-1]=='e' || s[i-1]=='E' || s[i-1]=='.' || s[i-1]=='+' || s[i-1]=='-'); --i)
        ;
      if(i==p)
        throw parse_exception("Wrong R value");
      std::istringstream st(s.substr(i, p-i));
      value_t x;
      st >> x;
      p=i;
      return x;
    }
 
    static std::ostream&
    print(const value_t v, std::ostream& o,
          const std::string& format = "text")
    {
      if(format == "json")
        o<< '"';
      o << v;
      if(format == "json")
        o<< '"';
      return o;
    }
 
    std::ostream&
    print_set(std::ostream& o, const std::string& format = "text") const
    {
      if (format == "latex")
        o << "\\mathbb{R}_{max,*}";
      else if (format == "text")
        o << "R-max-prod";
      else
        raise("invalid format: ", format);
      return o;
    }
 
    template<unsigned version = version::fsm_json>
    value_t
    value_from_json(json::node_t const* p) const {
      version::check_fsmjson<version>();
      switch (version) {
        case 0: /* Never occurs due to above check. */
        case 1:
        default:
          return p->to_double();
      }
    }
 
      template<unsigned version = version::fsm_json>
      static json::node_t* 
      to_json()
    {
      version::check_fsmjson<version>();
      switch (version) {
        case 0: /* Never occurs due to above check. */
        case 1:
        default:
          return new json::object_t( "semiring",
                                     new json::string_t("R-max-prod"));
      }
    }
 
    template<unsigned version = version::fsm_json>
    json::node_t* value_to_json(value_t v) 
    const
    {
      version::check_fsmjson<version>();
      switch (version) {
        case 0: /* Never occurs due to above check. */
        case 1:
        default:
          return new json::float_t(v);
      }
    }
 
  };
 
    inline pmax join(const pmax&, const pmax&) { return {}; }
    
    inline pmax join(const b&, const pmax&) { return {}; }
    inline pmax join(const pmax&, const b&) { return {}; }
 
 }
}//end of ns awali::stc
 
#endif // !AWALI_WEIGHTSET_PMAX_HH