/* Pango * pango-script.c: Script tag handling * * Copyright (C) 2002 Red Hat Software * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 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 * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. * * Implementation of pango_script_iter is derived from ICU: * *  icu/sources/common/usc_impl.c * ********************************************************************** *   Copyright (C) 1999-2002, International Business Machines *   Corporation and others.  All Rights Reserved. ********************************************************************** * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the * "Software"), to deal in the Software without restriction, including * without limitation the rights to use, copy, modify, merge, publish, * distribute, and/or sell copies of the Software, and to permit persons * to whom the Software is furnished to do so, provided that the above * copyright notice(s) and this permission notice appear in all copies of * the Software and that both the above copyright notice(s) and this * permission notice appear in supporting documentation. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT * OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR * HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. * * Except as contained in this notice, the name of a copyright holder * shall not be used in advertising or otherwise to promote the sale, use * or other dealings in this Software without prior written authorization * of the copyright holder. */#include <config.h>#include <stdlib.h>#include <string.h>#include "pango-script.h"#include "pango-script-table.h"#define PAREN_STACK_DEPTH 128typedef struct _ParenStackEntry ParenStackEntry;struct _ParenStackEntry{  int pair_index;  PangoScript script_code;};struct _PangoScriptIter{  const gchar *text_start;  const gchar *text_end;  const gchar *script_start;  const gchar *script_end;  PangoScript script_code;  ParenStackEntry paren_stack[PAREN_STACK_DEPTH];  int paren_sp;};#define PANGO_SCRIPT_TABLE_MIDPOINT (G_N_ELEMENTS (pango_script_table) / 2)static inline PangoScriptpango_script_for_unichar_bsearch (gunichar ch){  int lower = 0;  int upper = G_N_ELEMENTS (pango_script_table) - 1;  static int saved_mid = PANGO_SCRIPT_TABLE_MIDPOINT;  int mid = saved_mid;  do    {      if (ch < pango_script_table[mid].start)	upper = mid - 1;      else if (ch >= pango_script_table[mid].start + pango_script_table[mid].chars)	lower = mid + 1;      else	return pango_script_table[saved_mid = mid].script;      mid = (lower + upper) / 2;    }  while (lower <= upper);  return PANGO_SCRIPT_UNKNOWN;}/** * pango_script_for_unichar: * @ch: a Unicode character * * Looks up the #PangoScript for a particular character (as defined by * Unicode Standard Annex #24). No check is made for @ch being a * valid Unicode character; if you pass in invalid character, the * result is undefined. * * Return value: the #PangoScript for the character. * * Since: 1.4 **/PangoScriptpango_script_for_unichar (gunichar ch){  if (ch < G_N_ELEMENTS (pango_script_easy_table))    return pango_script_easy_table[ch];  else    return pango_script_for_unichar_bsearch (ch);}/**********************************************************************//** * pango_script_iter_new: * @text: a UTF-8 string * @length: length of @text, or -1 if @text is nul-terminated. * * Create a new #PangoScriptIter, used to break a string of * Unicode into runs by text. No copy is made of @text, so * the caller needs to make sure it remains valid until * the iterator is freed with pango_script_iter_free ().x * * Return value: the new script iterator, initialized *  to point at the first range in the text, which should be *  freed with pango_script_iter_free(). If the string is *  empty, it will point at an empty range. * * Since: 1.4 **/PangoScriptIter *pango_script_iter_new (const char *text,		       int         length){  PangoScriptIter *iter = g_slice_new (PangoScriptIter);  iter->text_start = text;  if (length >= 0)    iter->text_end = text + length;  else    iter->text_end = text + strlen (text);  iter->script_start = text;  iter->script_end = text;  iter->script_code = PANGO_SCRIPT_COMMON;  iter->paren_sp = -1;  pango_script_iter_next (iter);  return iter;}/** * pango_script_iter_free: * @iter: a #PangoScriptIter * * Frees a #PangoScriptIter created with pango_script_iter_new(). * * Since: 1.4 **/voidpango_script_iter_free (PangoScriptIter *iter){  g_slice_free (PangoScriptIter, iter);}/** * pango_script_iter_get_range: * @iter: a #PangoScriptIter * @start: location to store start position of the range, or %NULL * @end: location to store end position of the range, or %NULL * @script: location to store script for range, or %NULL * * Gets information about the range to which @iter currently points. * The range is the set of locations p where *start <= p < *end. * (That is, it doesn't include the character stored at *end) * * Since: 1.4 **/voidpango_script_iter_get_range (PangoScriptIter      *iter,			     G_CONST_RETURN char **start,			     G_CONST_RETURN char **end,			     PangoScript          *script){  if (start)    *start = iter->script_start;  if (end)    *end = iter->script_end;  if (script)    *script = iter->script_code;}static const gunichar paired_chars[] = {  0x0028, 0x0029, /* ascii paired punctuation */  0x003c, 0x003e,  0x005b, 0x005d,  0x007b, 0x007d,  0x00ab, 0x00bb, /* guillemets */  0x2018, 0x2019, /* general punctuation */  0x201c, 0x201d,  0x2039, 0x203a,  0x3008, 0x3009, /* chinese paired punctuation */  0x300a, 0x300b,  0x300c, 0x300d,  0x300e, 0x300f,  0x3010, 0x3011,  0x3014, 0x3015,  0x3016, 0x3017,  0x3018, 0x3019,  0x301a, 0x301b};static intget_pair_index (gunichar ch){  int lower = 0;  int upper = G_N_ELEMENTS (paired_chars) - 1;  while (lower <= upper)    {      int mid = (lower + upper) / 2;      if (ch < paired_chars[mid])	upper = mid - 1;      else if (ch > paired_chars[mid])	lower = mid + 1;      else	return mid;    }  return -1;}#define REAL_SCRIPT(script) \  ((script) > PANGO_SCRIPT_INHERITED)#define SAME_SCRIPT(script1, script2) \  (!REAL_SCRIPT (script1) || !REAL_SCRIPT (script2) || (script1) == (script2))#define IS_OPEN(pair_index) (((pair_index) & 1) == 0)/** * pango_script_iter_next: * @iter: a #PangoScriptIter * * Advances a #PangoScriptIter to the next range. If @iter * is already at the end, it is left unchanged and %FALSE * is returned. * * Return value: %TRUE if @iter was successfully advanced. * * Since: 1.4 **/gbooleanpango_script_iter_next (PangoScriptIter *iter){  int start_sp;  if (iter->script_end == iter->text_end)    return FALSE;  start_sp = iter->paren_sp;  iter->script_code = PANGO_SCRIPT_COMMON;  iter->script_start = iter->script_end;  for (; iter->script_end < iter->text_end; iter->script_end = g_utf8_next_char (iter->script_end))    {      gunichar ch = g_utf8_get_char (iter->script_end);      PangoScript sc;      int pair_index;      sc = pango_script_for_unichar (ch);      if (sc != PANGO_SCRIPT_COMMON)	pair_index = -1;      else	pair_index = get_pair_index (ch);