/*
  *  MoMEMta: a modular implementation of the Matrix Element Method
  *  Copyright (C) 2016  Universite catholique de Louvain (UCL), Belgium
  *
  *  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/>.
  */
 
 
 #pragma once
 
 #include <momemta/any.h>
 
 #include <memory>
 #include <stdexcept>
 #include <string>
 #include <vector>
 
 struct InputTag {
     public:
         InputTag(const std::string& module, const std::string& parameter);
         InputTag(const std::string& module, const std::string& parameter, size_t index);
         InputTag() = default;
 
         static bool isInputTag(const std::string& tag);
 
         static InputTag fromString(const std::string& tag);
 
         bool operator==(const InputTag& rhs) const;
 
         std::string toString() const;
 
         bool isIndexed() const;
 
         bool empty() const;
 
         void update();
 
         std::string module; 
         std::string parameter; 
         size_t index; 
 
     private:
         class tag_not_resolved_error: public std::runtime_error {
             using std::runtime_error::runtime_error;
         };
 
         bool indexed = false;
 
         std::string string_representation;
 };
 
 namespace std {
     template<>
         struct hash<InputTag> {
             size_t operator()(const InputTag& tag) const {
                 return string_hash(tag.module) + string_hash(tag.parameter);
             }
 
             private:
                 std::hash<std::string> string_hash;
         };
 }