tanl: tanl: tag/Tanlpos/State.h Source File

00001 /*
00002 **  Tanl
00003 **  tag/TanlPos/State.h
00004 **  ----------------------------------------------------------------------
00005 **  Copyright (c) 2005  Giuseppe Attardi (attardi@di.unipi.it).
00006 **  ----------------------------------------------------------------------
00007 **
00008 **  This file is part of Tanl.
00009 **
00010 **  Tanl is free software; you can redistribute it and/or modify it
00011 **  under the terms of the GNU General Public License, version 3,
00012 **  as published by the Free Software Foundation.
00013 **
00014 **  Tanl is distributed in the hope that it will be useful,
00015 **  but WITHOUT ANY WARRANTY; without even the implied warranty of
00016 **  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00017 **  GNU General Public License for more details.
00018 **
00019 **  You should have received a copy of the GNU General Public License
00020 **  along with this program.  If not, see <http://www.gnu.org/licenses/>.
00021 **  ----------------------------------------------------------------------
00022 */
00023 
00024 #ifndef Tanl_POS_State_H
00025 #define Tanl_POS_State_H
00026 
00027 #include "Tag.h"
00028 
00029 // standard
00030 #include <vector>
00031 #include <tr1/unordered_map>
00032 
00033 namespace Tanl { namespace POS {
00034 
00039 struct State : public std::vector<TagID>
00040 {
00041   State(TagID tag = 0) : std::vector<TagID>(tag_order + 1, tag) { }
00042 
00043   // FIXME: avoid making full copy, using a linked list? Beppe
00044   State add(TagID n) {
00045     State res(size());
00046     res[0] = n;
00047     for (int i = 1; i < size(); ++i)
00048       res[i+1] = (*this)[i];
00049     return res;
00050   }
00051 
00052   int compareTo(State const& other) const {
00053     int i = 0;
00054     for (; i <= tag_order && i < size() && i < other.size(); i++) {
00055       TagID t1 = (*this)[i];
00056       TagID t2 = other[i];
00057       if (t1 < t2)
00058         return -1;
00059       else if (t1 > t2)
00060         return 1;
00061     }
00062     if (i > tag_order || i == size() && i == other.size())
00063       return 0;
00064     return (i == size()) ? -1 : 1;
00065   }
00066 
00067   static int tag_order;         
00068 
00069 };
00070  
00071  inline bool operator ==(State const& s1, State const& s2) {
00072    return s1.compareTo(s2) == 0;
00073  }
00074 
00075 } // namespace POS
00076 } // namespace Tanl
00077 
00078 namespace std { namespace tr1 {
00079 
00080   template<>
00081   struct hash<Tanl::POS::State const&> : public std::unary_function<Tanl::POS::State const&, std::size_t>
00082     {      
00083       std::size_t operator()(Tanl::POS::State const& __s) const
00084       {
00085         unsigned long __h = 0;
00086         for (int i = 0; i < __s.size() ; ++i)
00087           __h = 131 * __h + (unsigned int)__s[i];
00088         return size_t(__h);
00089       }
00090     };
00091 }}
00092 
00093 #endif // Tanl_POS_State_H