738 lines
22 KiB
C
738 lines
22 KiB
C
/* vim: set tabstop=4 shiftwidth=4: */
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/*
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* Line breaking in a Unicode sequence. Designed to be used in a
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* generic text renderer.
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*
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* Copyright (C) 2008-2010 Wu Yongwei <wuyongwei at gmail dot com>
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*
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* This software is provided 'as-is', without any express or implied
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* warranty. In no event will the author be held liable for any damages
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* arising from the use of this software.
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*
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* Permission is granted to anyone to use this software for any purpose,
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* including commercial applications, and to alter it and redistribute
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* it freely, subject to the following restrictions:
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*
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* 1. The origin of this software must not be misrepresented; you must
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* not claim that you wrote the original software. If you use this
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* software in a product, an acknowledgement in the product
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* documentation would be appreciated but is not required.
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* 2. Altered source versions must be plainly marked as such, and must
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* not be misrepresented as being the original software.
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* 3. This notice may not be removed or altered from any source
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* distribution.
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*
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* The main reference is Unicode Standard Annex 14 (UAX #14):
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* <URL:http://www.unicode.org/reports/tr14/>
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*
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* When this library was designed, this annex was at Revision 19, for
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* Unicode 5.0.0:
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* <URL:http://www.unicode.org/reports/tr14/tr14-19.html>
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*
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* This library has been updated according to Revision 24, for
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* Unicode 5.2.0:
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* <URL:http://www.unicode.org/reports/tr14/tr14-24.html>
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*
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* The Unicode Terms of Use are available at
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* <URL:http://www.unicode.org/copyright.html>
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*/
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/**
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* @file linebreak.c
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*
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* Implementation of the line breaking algorithm as described in Unicode
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* Standard Annex 14.
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*
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* @version 2.0, 2010/01/03
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* @author Wu Yongwei
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*/
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#include <assert.h>
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#include <stddef.h>
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#include <string.h>
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#include "linebreak.h"
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#include "linebreakdef.h"
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/**
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* Size of the second-level index to the line breaking properties.
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*/
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#define LINEBREAK_INDEX_SIZE 40
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/**
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* Version number of the library.
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*/
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const int linebreak_version = LINEBREAK_VERSION;
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/**
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* Enumeration of break actions. They are used in the break action
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* pair table below.
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*/
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enum BreakAction
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{
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DIR_BRK, /**< Direct break opportunity */
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IND_BRK, /**< Indirect break opportunity */
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CMI_BRK, /**< Indirect break opportunity for combining marks */
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CMP_BRK, /**< Prohibited break for combining marks */
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PRH_BRK /**< Prohibited break */
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};
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/**
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* Break action pair table. This is a direct mapping of Table 2 of
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* Unicode Standard Annex 14, Revision 24.
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*/
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static enum BreakAction baTable[LBP_JT][LBP_JT] = {
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{ /* OP */
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PRH_BRK, PRH_BRK, PRH_BRK, PRH_BRK, PRH_BRK, PRH_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, PRH_BRK, PRH_BRK, PRH_BRK, PRH_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, PRH_BRK, PRH_BRK, PRH_BRK, PRH_BRK, CMP_BRK,
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PRH_BRK, PRH_BRK, PRH_BRK, PRH_BRK, PRH_BRK, PRH_BRK },
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{ /* CL */
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DIR_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, PRH_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, DIR_BRK,
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DIR_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK },
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{ /* CP */
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DIR_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, PRH_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK, DIR_BRK,
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DIR_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK },
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{ /* QU */
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PRH_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK,
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IND_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK },
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{ /* GL */
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IND_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK,
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IND_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK },
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{ /* NS */
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DIR_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK,
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DIR_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK },
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{ /* EX */
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DIR_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK,
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DIR_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK },
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{ /* SY */
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DIR_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, DIR_BRK, IND_BRK, DIR_BRK, DIR_BRK,
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DIR_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK },
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{ /* IS */
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DIR_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, DIR_BRK, IND_BRK, IND_BRK, DIR_BRK,
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DIR_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK },
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{ /* PR */
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IND_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, DIR_BRK, IND_BRK, IND_BRK, IND_BRK,
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DIR_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK },
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{ /* PO */
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IND_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, DIR_BRK, IND_BRK, IND_BRK, DIR_BRK,
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DIR_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK },
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{ /* NU */
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IND_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK, DIR_BRK,
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IND_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK },
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{ /* AL */
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IND_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, DIR_BRK, IND_BRK, IND_BRK, DIR_BRK,
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IND_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK },
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{ /* ID */
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DIR_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, IND_BRK, DIR_BRK, DIR_BRK, DIR_BRK,
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IND_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK },
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{ /* IN */
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DIR_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK,
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IND_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK },
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{ /* HY */
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DIR_BRK, PRH_BRK, PRH_BRK, IND_BRK, DIR_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, DIR_BRK, IND_BRK, DIR_BRK, DIR_BRK,
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DIR_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK },
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{ /* BA */
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DIR_BRK, PRH_BRK, PRH_BRK, IND_BRK, DIR_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK,
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DIR_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK },
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{ /* BB */
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IND_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK,
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IND_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK },
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{ /* B2 */
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DIR_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK,
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DIR_BRK, IND_BRK, IND_BRK, DIR_BRK, PRH_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK },
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{ /* ZW */
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DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK,
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DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK,
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DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, PRH_BRK, DIR_BRK,
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DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK },
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{ /* CM */
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IND_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, DIR_BRK, IND_BRK, IND_BRK, DIR_BRK,
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IND_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK },
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{ /* WJ */
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IND_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK,
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IND_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK },
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{ /* H2 */
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DIR_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, IND_BRK, DIR_BRK, DIR_BRK, DIR_BRK,
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IND_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, IND_BRK, IND_BRK },
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{ /* H3 */
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DIR_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, IND_BRK, DIR_BRK, DIR_BRK, DIR_BRK,
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IND_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, IND_BRK },
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{ /* JL */
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DIR_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, IND_BRK, DIR_BRK, DIR_BRK, DIR_BRK,
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IND_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, IND_BRK, IND_BRK, IND_BRK, IND_BRK, DIR_BRK },
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{ /* JV */
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DIR_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, IND_BRK, DIR_BRK, DIR_BRK, DIR_BRK,
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IND_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, IND_BRK, IND_BRK },
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{ /* JT */
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DIR_BRK, PRH_BRK, PRH_BRK, IND_BRK, IND_BRK, IND_BRK, PRH_BRK,
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PRH_BRK, PRH_BRK, DIR_BRK, IND_BRK, DIR_BRK, DIR_BRK, DIR_BRK,
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IND_BRK, IND_BRK, IND_BRK, DIR_BRK, DIR_BRK, PRH_BRK, CMI_BRK,
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PRH_BRK, DIR_BRK, DIR_BRK, DIR_BRK, DIR_BRK, IND_BRK }
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};
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/**
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* Struct for the second-level index to the line breaking properties.
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*/
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struct LineBreakPropertiesIndex
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{
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utf32_t end; /**< End coding point */
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struct LineBreakProperties *lbp;/**< Pointer to line breaking properties */
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};
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/**
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* Second-level index to the line breaking properties.
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*/
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static struct LineBreakPropertiesIndex lb_prop_index[LINEBREAK_INDEX_SIZE] =
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{
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{ 0xFFFFFFFF, lb_prop_default }
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};
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/**
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* Initializes the second-level index to the line breaking properties.
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* If it is not called, the performance of #get_char_lb_class_lang (and
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* thus the main functionality) can be pretty bad, especially for big
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* code points like those of Chinese.
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*/
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void init_linebreak(void)
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{
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size_t i;
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size_t iPropDefault;
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size_t len;
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size_t step;
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len = 0;
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while (lb_prop_default[len].prop != LBP_Undefined)
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++len;
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step = len / LINEBREAK_INDEX_SIZE;
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iPropDefault = 0;
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for (i = 0; i < LINEBREAK_INDEX_SIZE; ++i)
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{
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lb_prop_index[i].lbp = lb_prop_default + iPropDefault;
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iPropDefault += step;
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lb_prop_index[i].end = lb_prop_default[iPropDefault].start - 1;
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}
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lb_prop_index[--i].end = 0xFFFFFFFF;
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}
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/**
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* Gets the language-specific line breaking properties.
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*
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* @param lang language of the text
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* @return pointer to the language-specific line breaking
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* properties array if found; \c NULL otherwise
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*/
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static struct LineBreakProperties *get_lb_prop_lang(const char *lang)
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{
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struct LineBreakPropertiesLang *lbplIter;
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if (lang != NULL)
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{
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for (lbplIter = lb_prop_lang_map; lbplIter->lang != NULL; ++lbplIter)
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{
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if (strncmp(lang, lbplIter->lang, lbplIter->namelen) == 0)
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{
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return lbplIter->lbp;
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}
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}
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}
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return NULL;
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}
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/**
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* Gets the line breaking class of a character from a line breaking
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* properties array.
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*
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* @param ch character to check
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* @param lbp pointer to the line breaking properties array
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* @return the line breaking class if found; \c LBP_XX otherwise
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*/
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static enum LineBreakClass get_char_lb_class(
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utf32_t ch,
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struct LineBreakProperties *lbp)
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{
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while (lbp->prop != LBP_Undefined && ch >= lbp->start)
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{
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if (ch <= lbp->end)
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return lbp->prop;
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++lbp;
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}
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return LBP_XX;
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}
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/**
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* Gets the line breaking class of a character from the default line
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* breaking properties array.
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*
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* @param ch character to check
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* @return the line breaking class if found; \c LBP_XX otherwise
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*/
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static enum LineBreakClass get_char_lb_class_default(
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utf32_t ch)
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{
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size_t i = 0;
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while (ch > lb_prop_index[i].end)
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++i;
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assert(i < LINEBREAK_INDEX_SIZE);
|
|
return get_char_lb_class(ch, lb_prop_index[i].lbp);
|
|
}
|
|
|
|
/**
|
|
* Gets the line breaking class of a character for a specific
|
|
* language. This function will check the language-specific data first,
|
|
* and then the default data if there is no language-specific property
|
|
* available for the character.
|
|
*
|
|
* @param ch character to check
|
|
* @param lbpLang pointer to the language-specific line breaking
|
|
* properties array
|
|
* @return the line breaking class if found; \c LBP_XX
|
|
* otherwise
|
|
*/
|
|
static enum LineBreakClass get_char_lb_class_lang(
|
|
utf32_t ch,
|
|
struct LineBreakProperties *lbpLang)
|
|
{
|
|
enum LineBreakClass lbcResult;
|
|
|
|
/* Find the language-specific line breaking class for a character */
|
|
if (lbpLang)
|
|
{
|
|
lbcResult = get_char_lb_class(ch, lbpLang);
|
|
if (lbcResult != LBP_XX)
|
|
return lbcResult;
|
|
}
|
|
|
|
/* Find the generic language-specific line breaking class, if no
|
|
* language context is provided, or language-specific data are not
|
|
* available for the specific character in the specified language */
|
|
return get_char_lb_class_default(ch);
|
|
}
|
|
|
|
/**
|
|
* Resolves the line breaking class for certain ambiguous or complicated
|
|
* characters. They are treated in a simplistic way in this
|
|
* implementation.
|
|
*
|
|
* @param lbc line breaking class to resolve
|
|
* @param lang language of the text
|
|
* @return the resolved line breaking class
|
|
*/
|
|
static enum LineBreakClass resolve_lb_class(
|
|
enum LineBreakClass lbc,
|
|
const char *lang)
|
|
{
|
|
switch (lbc)
|
|
{
|
|
case LBP_AI:
|
|
if (lang != NULL &&
|
|
(strncmp(lang, "zh", 2) == 0 || /* Chinese */
|
|
strncmp(lang, "ja", 2) == 0 || /* Japanese */
|
|
strncmp(lang, "ko", 2) == 0)) /* Korean */
|
|
{
|
|
return LBP_ID;
|
|
}
|
|
/* Fall through */
|
|
case LBP_SA:
|
|
case LBP_SG:
|
|
case LBP_XX:
|
|
return LBP_AL;
|
|
default:
|
|
return lbc;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Gets the next Unicode character in a UTF-8 sequence. The index will
|
|
* be advanced to the next complete character, unless the end of string
|
|
* is reached in the middle of a UTF-8 sequence.
|
|
*
|
|
* @param[in] s input UTF-8 string
|
|
* @param[in] len length of the string in bytes
|
|
* @param[in,out] ip pointer to the index
|
|
* @return the Unicode character beginning at the index; or
|
|
* #EOS if end of input is encountered
|
|
*/
|
|
utf32_t lb_get_next_char_utf8(
|
|
const utf8_t *s,
|
|
size_t len,
|
|
size_t *ip)
|
|
{
|
|
utf8_t ch;
|
|
utf32_t res;
|
|
|
|
assert(*ip <= len);
|
|
if (*ip == len)
|
|
return EOS;
|
|
ch = s[*ip];
|
|
|
|
if (ch < 0xC2 || ch > 0xF4)
|
|
{ /* One-byte sequence, tail (should not occur), or invalid */
|
|
*ip += 1;
|
|
return ch;
|
|
}
|
|
else if (ch < 0xE0)
|
|
{ /* Two-byte sequence */
|
|
if (*ip + 2 > len)
|
|
return EOS;
|
|
res = ((ch & 0x1F) << 6) + (s[*ip + 1] & 0x3F);
|
|
*ip += 2;
|
|
return res;
|
|
}
|
|
else if (ch < 0xF0)
|
|
{ /* Three-byte sequence */
|
|
if (*ip + 3 > len)
|
|
return EOS;
|
|
res = ((ch & 0x0F) << 12) +
|
|
((s[*ip + 1] & 0x3F) << 6) +
|
|
((s[*ip + 2] & 0x3F));
|
|
*ip += 3;
|
|
return res;
|
|
}
|
|
else
|
|
{ /* Four-byte sequence */
|
|
if (*ip + 4 > len)
|
|
return EOS;
|
|
res = ((ch & 0x07) << 18) +
|
|
((s[*ip + 1] & 0x3F) << 12) +
|
|
((s[*ip + 2] & 0x3F) << 6) +
|
|
((s[*ip + 3] & 0x3F));
|
|
*ip += 4;
|
|
return res;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Gets the next Unicode character in a UTF-16 sequence. The index will
|
|
* be advanced to the next complete character, unless the end of string
|
|
* is reached in the middle of a UTF-16 surrogate pair.
|
|
*
|
|
* @param[in] s input UTF-16 string
|
|
* @param[in] len length of the string in words
|
|
* @param[in,out] ip pointer to the index
|
|
* @return the Unicode character beginning at the index; or
|
|
* #EOS if end of input is encountered
|
|
*/
|
|
utf32_t lb_get_next_char_utf16(
|
|
const utf16_t *s,
|
|
size_t len,
|
|
size_t *ip)
|
|
{
|
|
utf16_t ch;
|
|
|
|
assert(*ip <= len);
|
|
if (*ip == len)
|
|
return EOS;
|
|
ch = s[(*ip)++];
|
|
|
|
if (ch < 0xD800 || ch > 0xDBFF)
|
|
{ /* If the character is not a high surrogate */
|
|
return ch;
|
|
}
|
|
if (*ip == len)
|
|
{ /* If the input ends here (an error) */
|
|
--(*ip);
|
|
return EOS;
|
|
}
|
|
if (s[*ip] < 0xDC00 || s[*ip] > 0xDFFF)
|
|
{ /* If the next character is not the low surrogate (an error) */
|
|
return ch;
|
|
}
|
|
/* Return the constructed character and advance the index again */
|
|
return (((utf32_t)ch & 0x3FF) << 10) + (s[(*ip)++] & 0x3FF) + 0x10000;
|
|
}
|
|
|
|
/**
|
|
* Gets the next Unicode character in a UTF-32 sequence. The index will
|
|
* be advanced to the next character.
|
|
*
|
|
* @param[in] s input UTF-32 string
|
|
* @param[in] len length of the string in dwords
|
|
* @param[in,out] ip pointer to the index
|
|
* @return the Unicode character beginning at the index; or
|
|
* #EOS if end of input is encountered
|
|
*/
|
|
utf32_t lb_get_next_char_utf32(
|
|
const utf32_t *s,
|
|
size_t len,
|
|
size_t *ip)
|
|
{
|
|
assert(*ip <= len);
|
|
if (*ip == len)
|
|
return EOS;
|
|
return s[(*ip)++];
|
|
}
|
|
|
|
/**
|
|
* Sets the line breaking information for a generic input string.
|
|
*
|
|
* @param[in] s input string
|
|
* @param[in] len length of the input
|
|
* @param[in] lang language of the input
|
|
* @param[out] brks pointer to the output breaking data,
|
|
* containing #LINEBREAK_MUSTBREAK,
|
|
* #LINEBREAK_ALLOWBREAK, #LINEBREAK_NOBREAK,
|
|
* or #LINEBREAK_INSIDEACHAR
|
|
* @param[in] get_next_char function to get the next UTF-32 character
|
|
*/
|
|
void set_linebreaks(
|
|
const void *s,
|
|
size_t len,
|
|
const char *lang,
|
|
char *brks,
|
|
get_next_char_t get_next_char)
|
|
{
|
|
utf32_t ch;
|
|
enum LineBreakClass lbcCur;
|
|
enum LineBreakClass lbcNew;
|
|
enum LineBreakClass lbcLast;
|
|
struct LineBreakProperties *lbpLang;
|
|
size_t posCur = 0;
|
|
size_t posLast = 0;
|
|
|
|
--posLast; /* To be ++'d later */
|
|
ch = get_next_char(s, len, &posCur);
|
|
if (ch == EOS)
|
|
return;
|
|
lbpLang = get_lb_prop_lang(lang);
|
|
lbcCur = resolve_lb_class(get_char_lb_class_lang(ch, lbpLang), lang);
|
|
lbcNew = LBP_Undefined;
|
|
|
|
nextline:
|
|
|
|
/* Special treatment for the first character */
|
|
switch (lbcCur)
|
|
{
|
|
case LBP_LF:
|
|
case LBP_NL:
|
|
lbcCur = LBP_BK;
|
|
break;
|
|
case LBP_CB:
|
|
lbcCur = LBP_BA;
|
|
break;
|
|
case LBP_SP:
|
|
lbcCur = LBP_WJ;
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
/* Process a line till an explicit break or end of string */
|
|
for (;;)
|
|
{
|
|
for (++posLast; posLast < posCur - 1; ++posLast)
|
|
{
|
|
brks[posLast] = LINEBREAK_INSIDEACHAR;
|
|
}
|
|
assert(posLast == posCur - 1);
|
|
lbcLast = lbcNew;
|
|
ch = get_next_char(s, len, &posCur);
|
|
if (ch == EOS)
|
|
break;
|
|
lbcNew = get_char_lb_class_lang(ch, lbpLang);
|
|
if (lbcCur == LBP_BK || (lbcCur == LBP_CR && lbcNew != LBP_LF))
|
|
{
|
|
brks[posLast] = LINEBREAK_MUSTBREAK;
|
|
lbcCur = resolve_lb_class(lbcNew, lang);
|
|
goto nextline;
|
|
}
|
|
|
|
switch (lbcNew)
|
|
{
|
|
case LBP_SP:
|
|
brks[posLast] = LINEBREAK_NOBREAK;
|
|
continue;
|
|
case LBP_BK:
|
|
case LBP_LF:
|
|
case LBP_NL:
|
|
brks[posLast] = LINEBREAK_NOBREAK;
|
|
lbcCur = LBP_BK;
|
|
continue;
|
|
case LBP_CR:
|
|
brks[posLast] = LINEBREAK_NOBREAK;
|
|
lbcCur = LBP_CR;
|
|
continue;
|
|
case LBP_CB:
|
|
brks[posLast] = LINEBREAK_ALLOWBREAK;
|
|
lbcCur = LBP_BA;
|
|
continue;
|
|
default:
|
|
break;
|
|
}
|
|
|
|
lbcNew = resolve_lb_class(lbcNew, lang);
|
|
|
|
assert(lbcCur <= LBP_JT);
|
|
assert(lbcNew <= LBP_JT);
|
|
switch (baTable[lbcCur - 1][lbcNew - 1])
|
|
{
|
|
case DIR_BRK:
|
|
brks[posLast] = LINEBREAK_ALLOWBREAK;
|
|
break;
|
|
case CMI_BRK:
|
|
case IND_BRK:
|
|
if (lbcLast == LBP_SP)
|
|
{
|
|
brks[posLast] = LINEBREAK_ALLOWBREAK;
|
|
}
|
|
else
|
|
{
|
|
brks[posLast] = LINEBREAK_NOBREAK;
|
|
}
|
|
break;
|
|
case CMP_BRK:
|
|
brks[posLast] = LINEBREAK_NOBREAK;
|
|
if (lbcLast != LBP_SP)
|
|
continue;
|
|
break;
|
|
case PRH_BRK:
|
|
brks[posLast] = LINEBREAK_NOBREAK;
|
|
break;
|
|
}
|
|
|
|
lbcCur = lbcNew;
|
|
}
|
|
|
|
assert(posLast == posCur - 1 && posCur <= len);
|
|
/* Break after the last character */
|
|
brks[posLast] = LINEBREAK_MUSTBREAK;
|
|
/* When the input contains incomplete sequences */
|
|
while (posCur < len)
|
|
{
|
|
brks[posCur++] = LINEBREAK_INSIDEACHAR;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Sets the line breaking information for a UTF-8 input string.
|
|
*
|
|
* @param[in] s input UTF-8 string
|
|
* @param[in] len length of the input
|
|
* @param[in] lang language of the input
|
|
* @param[out] brks pointer to the output breaking data, containing
|
|
* #LINEBREAK_MUSTBREAK, #LINEBREAK_ALLOWBREAK,
|
|
* #LINEBREAK_NOBREAK, or #LINEBREAK_INSIDEACHAR
|
|
*/
|
|
void set_linebreaks_utf8(
|
|
const utf8_t *s,
|
|
size_t len,
|
|
const char *lang,
|
|
char *brks)
|
|
{
|
|
set_linebreaks(s, len, lang, brks,
|
|
(get_next_char_t)lb_get_next_char_utf8);
|
|
}
|
|
|
|
/**
|
|
* Sets the line breaking information for a UTF-16 input string.
|
|
*
|
|
* @param[in] s input UTF-16 string
|
|
* @param[in] len length of the input
|
|
* @param[in] lang language of the input
|
|
* @param[out] brks pointer to the output breaking data, containing
|
|
* #LINEBREAK_MUSTBREAK, #LINEBREAK_ALLOWBREAK,
|
|
* #LINEBREAK_NOBREAK, or #LINEBREAK_INSIDEACHAR
|
|
*/
|
|
void set_linebreaks_utf16(
|
|
const utf16_t *s,
|
|
size_t len,
|
|
const char *lang,
|
|
char *brks)
|
|
{
|
|
set_linebreaks(s, len, lang, brks,
|
|
(get_next_char_t)lb_get_next_char_utf16);
|
|
}
|
|
|
|
/**
|
|
* Sets the line breaking information for a UTF-32 input string.
|
|
*
|
|
* @param[in] s input UTF-32 string
|
|
* @param[in] len length of the input
|
|
* @param[in] lang language of the input
|
|
* @param[out] brks pointer to the output breaking data, containing
|
|
* #LINEBREAK_MUSTBREAK, #LINEBREAK_ALLOWBREAK,
|
|
* #LINEBREAK_NOBREAK, or #LINEBREAK_INSIDEACHAR
|
|
*/
|
|
void set_linebreaks_utf32(
|
|
const utf32_t *s,
|
|
size_t len,
|
|
const char *lang,
|
|
char *brks)
|
|
{
|
|
set_linebreaks(s, len, lang, brks,
|
|
(get_next_char_t)lb_get_next_char_utf32);
|
|
}
|
|
|
|
/**
|
|
* Tells whether a line break can occur between two Unicode characters.
|
|
* This is a wrapper function to expose a simple interface. Generally
|
|
* speaking, it is better to use #set_linebreaks_utf32 instead, since
|
|
* complicated cases involving combining marks, spaces, etc. cannot be
|
|
* correctly processed.
|
|
*
|
|
* @param char1 the first Unicode character
|
|
* @param char2 the second Unicode character
|
|
* @param lang language of the input
|
|
* @return one of #LINEBREAK_MUSTBREAK, #LINEBREAK_ALLOWBREAK,
|
|
* #LINEBREAK_NOBREAK, or #LINEBREAK_INSIDEACHAR
|
|
*/
|
|
int is_line_breakable(
|
|
utf32_t char1,
|
|
utf32_t char2,
|
|
const char* lang)
|
|
{
|
|
utf32_t s[2];
|
|
char brks[2];
|
|
s[0] = char1;
|
|
s[1] = char2;
|
|
set_linebreaks_utf32(s, 2, lang, brks);
|
|
return brks[0];
|
|
}
|