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/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* libdatrie - Double-Array Trie Library
* Copyright (C) 2006 Theppitak Karoonboonyanan <theppitak@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
* alpha-map.h - map between character codes and trie alphabet
* Created: 2006-08-19
* Author: Theppitak Karoonboonyanan <theppitak@gmail.com>
*/
#ifndef __ALPHA_MAP_H
#define __ALPHA_MAP_H
#include <stdio.h>
#include "typedefs.h"
#include "triedefs.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @file alpha-map.h
* @brief AlphaMap data type and functions
*
* AlphaMap is a mapping between AlphaChar and TrieChar. AlphaChar is the
* alphabet character used in words of a target language, while TrieChar
* is a small integer with packed range of values and is actually used in
* trie state transition calculations.
*
* Since double-array trie relies on sparse state transition table,
* a small set of input characters can make the table small, i.e. with
* small number of columns. But in real life, alphabet characters can be
* of non-continuous range of values. The unused slots between them can
* waste the space in the table, and can increase the chance of unused
* array cells.
*
* AlphaMap is thus defined for mapping between non-continuous ranges of
* values of AlphaChar and packed and continuous range of Triechar.
*
* In this implementation, TrieChar is defined as a single-byte integer,
* which means the largest AlphaChar set that is supported is of 255
* values, as the special value of 0 is reserved for null-termination code.
*/
/**
* @brief AlphaMap data type
*/
typedef struct _AlphaMap AlphaMap;
AlphaMap * alpha_map_new (void);
AlphaMap * alpha_map_clone (const AlphaMap *a_map);
void alpha_map_free (AlphaMap *alpha_map);
int alpha_map_add_range (AlphaMap *alpha_map,
AlphaChar begin,
AlphaChar end);
int alpha_char_strlen (const AlphaChar *str);
int alpha_char_strcmp (const AlphaChar *str1, const AlphaChar *str2);
#ifdef __cplusplus
}
#endif
#endif /* __ALPHA_MAP_H */
/*
vi:ts=4:ai:expandtab
*/
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