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/*
******************************************************************************
* Copyright (C) 1996-2011, International Business Machines Corporation and   *
* others. All Rights Reserved.                                               *
******************************************************************************
*/

package com.ibm.icu.lang;

import com.ibm.icu.impl.UCharacterName;
import com.ibm.icu.impl.UCharacterNameChoice;
import com.ibm.icu.util.ValueIterator;

/**
 * 

Class enabling iteration of the codepoints and their names.

*

Result of each iteration contains a valid codepoint that has valid * name.

*

See UCharacter.getNameIterator() for an example of use.

* @author synwee * @since release 2.1, March 5 2002 */ class UCharacterNameIterator implements ValueIterator { // public methods ---------------------------------------------------- /** *

Gets the next result for this iteration and returns * true if we are not at the end of the iteration, false otherwise.

*

If the return boolean is a false, the contents of elements will not * be updated.

* @param element for storing the result codepoint and name * @return true if we are not at the end of the iteration, false otherwise. * @see com.ibm.icu.util.ValueIterator.Element */ public boolean next(ValueIterator.Element element) { if (m_current_ >= m_limit_) { return false; } if (m_choice_ == UCharacterNameChoice.UNICODE_CHAR_NAME || m_choice_ == UCharacterNameChoice.EXTENDED_CHAR_NAME ) { int length = m_name_.getAlgorithmLength(); if (m_algorithmIndex_ < length) { while (m_algorithmIndex_ < length) { // find the algorithm range that could contain m_current_ if (m_algorithmIndex_ < 0 || m_name_.getAlgorithmEnd(m_algorithmIndex_) < m_current_) { m_algorithmIndex_ ++; } else { break; } } if (m_algorithmIndex_ < length) { // interleave the data-driven ones with the algorithmic ones // iterate over all algorithmic ranges; assume that they are // in ascending order int start = m_name_.getAlgorithmStart(m_algorithmIndex_); if (m_current_ < start) { // this should get rid of those codepoints that are not // in the algorithmic range int end = start; if (m_limit_ <= start) { end = m_limit_; } if (!iterateGroup(element, end)) { m_current_ ++; return true; } } /* // "if (m_current_ >= m_limit_)" would not return true // because it can never be reached due to: // 1) It has already been checked earlier // 2) When m_current_ is updated earlier, it returns true // 3) No updates on m_limit_*/ if (m_current_ >= m_limit_) { // after iterateGroup fails, current codepoint may be // greater than limit return false; } element.integer = m_current_; element.value = m_name_.getAlgorithmName(m_algorithmIndex_, m_current_); // reset the group index if we are in the algorithmic names m_groupIndex_ = -1; m_current_ ++; return true; } } } // enumerate the character names after the last algorithmic range if (!iterateGroup(element, m_limit_)) { m_current_ ++; return true; } else if (m_choice_ == UCharacterNameChoice.EXTENDED_CHAR_NAME) { if (!iterateExtended(element, m_limit_)) { m_current_ ++; return true; } } return false; } /** *

Resets the iterator to start iterating from the integer index * UCharacter.MIN_VALUE or X if a setRange(X, Y) has been called previously. *

*/ public void reset() { m_current_ = m_start_; m_groupIndex_ = -1; m_algorithmIndex_ = -1; } /** *

Restricts the range of integers to iterate and resets the iteration * to begin at the index argument start.

*

If setRange(start, end) is not performed before next(element) is * called, the iteration will start from the integer index * UCharacter.MIN_VALUE and end at UCharacter.MAX_VALUE.

*

* If this range is set outside the range of UCharacter.MIN_VALUE and * UCharacter.MAX_VALUE, next(element) will always return false. *

* @param start first integer in range to iterate * @param limit 1 integer after the last integer in range * @exception IllegalArgumentException thrown when attempting to set an * illegal range. E.g limit <= start */ public void setRange(int start, int limit) { if (start >= limit) { throw new IllegalArgumentException( "start or limit has to be valid Unicode codepoints and start < limit"); } if (start < UCharacter.MIN_VALUE) { m_start_ = UCharacter.MIN_VALUE; } else { m_start_ = start; } if (limit > UCharacter.MAX_VALUE + 1) { m_limit_ = UCharacter.MAX_VALUE + 1; } else { m_limit_ = limit; } m_current_ = m_start_; } // protected constructor --------------------------------------------- /** * Constructor * @param name name data * @param choice name choice from the class * com.ibm.icu.lang.UCharacterNameChoice */ protected UCharacterNameIterator(UCharacterName name, int choice) { if(name==null){ throw new IllegalArgumentException("UCharacterName name argument cannot be null. Missing unames.icu?"); } m_name_ = name; // no explicit choice in UCharacter so no checks on choice m_choice_ = choice; m_start_ = UCharacter.MIN_VALUE; m_limit_ = UCharacter.MAX_VALUE + 1; m_current_ = m_start_; } // private data members --------------------------------------------- /** * Name data */ private UCharacterName m_name_; /** * Name choice */ private int m_choice_; /** * Start iteration range */ private int m_start_; /** * End + 1 iteration range */ private int m_limit_; /** * Current codepoint */ private int m_current_; /** * Group index */ private int m_groupIndex_ = -1; /** * Algorithm index */ private int m_algorithmIndex_ = -1; /** * Group use */ private static char GROUP_OFFSETS_[] = new char[UCharacterName.LINES_PER_GROUP_ + 1]; private static char GROUP_LENGTHS_[] = new char[UCharacterName.LINES_PER_GROUP_ + 1]; // private methods -------------------------------------------------- /** * Group name iteration, iterate all the names in the current 32-group and * returns the first codepoint that has a valid name. * @param result stores the result codepoint and name * @param limit last codepoint + 1 in range to search * @return false if a codepoint with a name is found in group and we can * bail from further iteration, true to continue on with the * iteration */ private boolean iterateSingleGroup(ValueIterator.Element result, int limit) { synchronized(GROUP_OFFSETS_) { synchronized(GROUP_LENGTHS_) { int index = m_name_.getGroupLengths(m_groupIndex_, GROUP_OFFSETS_, GROUP_LENGTHS_); while (m_current_ < limit) { int offset = UCharacterName.getGroupOffset(m_current_); String name = m_name_.getGroupName( index + GROUP_OFFSETS_[offset], GROUP_LENGTHS_[offset], m_choice_); if ((name == null || name.length() == 0) && m_choice_ == UCharacterNameChoice.EXTENDED_CHAR_NAME) { name = m_name_.getExtendedName(m_current_); } if (name != null && name.length() > 0) { result.integer = m_current_; result.value = name; return false; } ++ m_current_; } } } return true; } /** * Group name iteration, iterate all the names in the current 32-group and * returns the first codepoint that has a valid name. * @param result stores the result codepoint and name * @param limit last codepoint + 1 in range to search * @return false if a codepoint with a name is found in group and we can * bail from further iteration, true to continue on with the * iteration */ private boolean iterateGroup(ValueIterator.Element result, int limit) { if (m_groupIndex_ < 0) { m_groupIndex_ = m_name_.getGroup(m_current_); } while (m_groupIndex_ < m_name_.m_groupcount_ && m_current_ < limit) { // iterate till the last group or the last codepoint int startMSB = UCharacterName.getCodepointMSB(m_current_); int gMSB = m_name_.getGroupMSB(m_groupIndex_); // can be -1 if (startMSB == gMSB) { if (startMSB == UCharacterName.getCodepointMSB(limit - 1)) { // if start and limit - 1 are in the same group, then enumerate // only in that one return iterateSingleGroup(result, limit); } // enumerate characters in the partial start group // if (m_name_.getGroupOffset(m_current_) != 0) { if (!iterateSingleGroup(result, UCharacterName.getGroupLimit(gMSB))) { return false; } ++ m_groupIndex_; // continue with the next group } else if (startMSB > gMSB) { // make sure that we start enumerating with the first group // after start m_groupIndex_ ++; } else { int gMIN = UCharacterName.getGroupMin(gMSB); if (gMIN > limit) { gMIN = limit; } if (m_choice_ == UCharacterNameChoice.EXTENDED_CHAR_NAME) { if (!iterateExtended(result, gMIN)) { return false; } } m_current_ = gMIN; } } return true; } /** * Iterate extended names. * @param result stores the result codepoint and name * @param limit last codepoint + 1 in range to search * @return false if a codepoint with a name is found and we can * bail from further iteration, true to continue on with the * iteration (this will always be false for valid codepoints) */ private boolean iterateExtended(ValueIterator.Element result, int limit) { while (m_current_ < limit) { String name = m_name_.getExtendedOr10Name(m_current_); if (name != null && name.length() > 0) { result.integer = m_current_; result.value = name; return false; } ++ m_current_; } return true; } }




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