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// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
/**
* @author Peter Boros
* @date 2004/08/20
* @version $Id$
* @file wordchartokenizer.h
* @brief Tokenizer based on the unicode WORDCHAR property.
*/
#pragma once
#include "tokenizer.h"
#include <iostream>
#include <vector>
#include <string>
#include <algorithm>
namespace fsa {
// {{{ class WordCharTokenizer
/**
* @class WordCharTokenizer
* @brief Tokenizer based on the Unicode WORDCHAR property.
*/
class WordCharTokenizer : public Tokenizer {
public:
/**
* @brief Enumareted type for specifying puctuation removal strategy.
*
* Enumareted type for specifying puctuation removal strategy. The
* following strategies are currently supported:
* - PUNCTUATION_DISCARD: discard all punctuation.
* - PUNCTUATION_FULL: honour all punctuation and insert
* punctuation token.
* - PUNCTUATION_SMART: same as PUNCTUATION_FULL, with some
* heuristics to not break acronyms and names.
* - PUNCTUATION_WHITESPACEONLY: treat everything (including
* punctuation) as word characters, except white space.
*/
enum Punctuation {
PUNCTUATION_DISCARD = 0,
PUNCTUATION_FULL,
PUNCTUATION_SMART,
PUNCTUATION_WHITESPACEONLY
};
private:
static const bool _punctuation_table[]; /**< Table used for punctuation tests. */
std::vector<std::string> _tokens; /**< Vector holding the tokens. */
unsigned int _current; /**< Index of current token. */
Punctuation _punctuation; /**< Punctuation strategy. */
std::string _punctuation_token; /**< Special token for marking punctuation. */
bool _lowercase; /**< Indicator whether tokens should be lowercased. */
public:
WordCharTokenizer(Punctuation punct = PUNCTUATION_DISCARD, const std::string &punct_token = ".") :
_tokens(),
_current(0),
_punctuation(punct),
_punctuation_token(punct_token),
_lowercase(true)
{}
virtual ~WordCharTokenizer() {}
Punctuation getPunctuation() const { return _punctuation; }
void setPunctuation(Punctuation punct) { _punctuation=punct; }
std::string getPunctuationToken() const { return _punctuation_token; }
void setPunctuationToken(const std::string &punct_token) { _punctuation_token=punct_token; }
void rewind() { _current=0; }
void setLowerCase(bool lc) { _lowercase = lc; }
bool getLowerCase() const { return _lowercase; }
/**
* @brief Initialize the tokenizer.
*
* @param text Input text.
* @return True on success.
*/
bool init(const std::string &text) override;
/**
* @brief Check if there are more tokens available.
*
* @return True if there are more tokens.
*/
bool hasMore() override;
/**
* @brief Get next token.
*
* @return Next token, or empty string if there are no more tokens left.
*/
std::string getNext() override;
};
// }}}
} // namespace fsa
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