languages/stem.cc

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/* Copyright (C) 2007,2008,2010 Olly Betts
 * Copyright (C) 2010 Evgeny Sizikov
 *
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 */

#include <config.h>

#include <xapian/stem.h>

#include <xapian/error.h>

#include "steminternal.h"

#include "allsnowballheaders.h"

#include <string>

using namespace std;

namespace Xapian {

Stem::Stem(const Stem & o) : internal(o.internal) { }

void
Stem::operator=(const Stem & o)
{
    internal = o.internal;
}

Stem::Stem() : internal(0) { }

Stem::Stem(const std::string &language) : internal(0) {
    if (language.empty()) return;
    switch (language[0]) {
        case 'd':
            if (language == "da" || language == "danish") {
                internal = new InternalStemDanish;
                return;
            }
            if (language == "dutch") {
                internal = new InternalStemDutch;
                return;
            }
            if (language == "de") {
                internal = new InternalStemGerman;
                return;
            }
            break;
        case 'e':
            if (language == "en" || language == "english") {
                internal = new InternalStemEnglish;
                return;
            }
            if (language == "es") {
                internal = new InternalStemSpanish;
                return;
            }
            break;
        case 'f':
            if (language == "fi" || language == "finnish") {
                internal = new InternalStemFinnish;
                return;
            }
            if (language == "fr" || language == "french") {
                internal = new InternalStemFrench;
                return;
            }
            break;
        case 'g':
            if (language == "german") {
                internal = new InternalStemGerman;
                return;
            }
            if (language == "german2") {
                internal = new InternalStemGerman2;
                return;
            }
            break;
        case 'h':
            if (language == "hu" || language == "hungarian") {
                internal = new InternalStemHungarian;
                return;
            }
            break;
        case 'i':
            if (language == "it" || language == "italian") {
                internal = new InternalStemItalian;
                return;
            }
            break;
        case 'k':
            if (language == "kraaij_pohlmann") {
                internal = new InternalStemKraaij_pohlmann;
                return;
            }
            break;
        case 'l':
            if (language == "lovins") {
                internal = new InternalStemLovins;
                return;
            }
            break;
        case 'n':
            if (language == "nl") {
                internal = new InternalStemDutch;
                return;
            }
            if (language == "no" || language == "nb" || language == "nn" ||
                language == "norwegian") {
                // Snowball's "Norwegian" stemmer works for both nb and nn
                // according to AlexB on #xapian.
                internal = new InternalStemNorwegian;
                return;
            }
            if (language == "none") {
                return;
            }
            break;
        case 'p':
            if (language == "pt" || language == "portuguese") {
                internal = new InternalStemPortuguese;
                return;
            }
            if (language == "porter") {
                internal = new InternalStemPorter;
                return;
            }
            break;
        case 'r':
            if (language == "ru" || language == "russian") {
                internal = new InternalStemRussian;
                return;
            }
            if (language == "ro" || language == "romanian") {
                internal = new InternalStemRomanian;
                return;
            }
            break;
        case 's':
            if (language == "spanish") {
                internal = new InternalStemSpanish;
                return;
            }
            if (language == "sv" || language == "swedish") {
                internal = new InternalStemSwedish;
                return;
            }
            break;
        case 't':
            if (language == "tr" || language == "turkish") {
                internal = new InternalStemTurkish;
                return;
            }
            break;
    }
    throw Xapian::InvalidArgumentError("Language code " + language + " unknown");
}

Stem::Stem(StemImplementation * p) : internal(p) { }

Stem::~Stem() { }

string
Stem::operator()(const std::string &word) const
{
    if (!internal.get() || word.empty()) return word;
    return internal->operator()(word);
}

string
Stem::get_description() const
{
    string desc = "Xapian::Stem(";
    if (internal.get()) {
        desc += internal->get_description();
        desc += ')';
    } else {
        desc += "none)";
    }
    return desc;
}

string
Stem::get_available_languages()
{
    return LANGSTRING;
}

}

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