list.hh

// This file is a part of Aurelia.
// Copyright (C) 2010  Valentin David
// Copyright (C) 2010  University of Bergen
//
// 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 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 __LIST_HH
# define __LIST_HH

# include <memory>

namespace aurelia {

  struct list_nil {
  private:
  public:
    enum : unsigned { size = 0 };
    list_nil() {}
    list_nil(const list_nil&) {}
    list_nil(list_nil&&) {}
  };

  template <typename T, typename Tail>
  struct list_cons {
  private:
    T h;
    Tail t;

  public:
    enum : unsigned { size = (unsigned)(Tail::size)+1 };

    list_cons(T&& h, const Tail& t):
      h(std::move(h)), t(t) {}

    list_cons(T&& h, Tail&& t):
      h(std::move(h)), t(std::move(t)) {}

    list_cons(const T& h, Tail&& t):
      h(h), t(std::move(t)) {}

    list_cons(const T& h, const Tail& t):
      h(h), t(t) {}

    list_cons(const list_cons& other):
      h(other.h), t(other.t) {}

    list_cons(list_cons&& other):
      h(std::move(other.h)), t(std::move(other.t)) {}

    const T& head() const {
      return h;
    }

    const Tail& tail() const {
      return t;
    }
  };

  template <typename H, typename T>
  H head(const list_cons<H,T>& l) {
    return l.head();
  }


  template <typename H, typename T>
  T tail(const list_cons<H,T>& l) {
    return l.tail();
  }

  template <typename H, typename T>
  list_cons<H,T> cons(const H& h, const T& t) {
    return list_cons<H,T>(h, t);
  };

  void head(list_nil);

  list_nil tail(list_nil);

  list_nil cons();

}

#endif