icuSources/i18n/uitercollationiterator.h

   1 // © 2016 and later: Unicode, Inc. and others.
   2 // License & terms of use: http://www.unicode.org/copyright.html
   3 /*
   4 *******************************************************************************
   5 * Copyright (C) 2012-2016, International Business Machines
   6 * Corporation and others.  All Rights Reserved.
   7 *******************************************************************************
   8 * uitercollationiterator.h
   9 *
  10 * created on: 2012sep23 (from utf16collationiterator.h)
  11 * created by: Markus W. Scherer
  12 */
  13
  14 #ifndef __UITERCOLLATIONITERATOR_H__
  15 #define __UITERCOLLATIONITERATOR_H__
  16
  17 #include "unicode/utypes.h"
  18
  19 #if !UCONFIG_NO_COLLATION
  20
  21 #include "unicode/uiter.h"
  22 #include "cmemory.h"
  23 #include "collation.h"
  24 #include "collationdata.h"
  25 #include "collationiterator.h"
  26 #include "normalizer2impl.h"
  27
  28 U_NAMESPACE_BEGIN
  29
  30 /**
  31  * UCharIterator-based collation element and character iterator.
  32  * Handles normalized text inline, with length or NUL-terminated.
  33  * Unnormalized text is handled by a subclass.
  34  */
  35 class U_I18N_API UIterCollationIterator : public CollationIterator {
  36 public:
  37     UIterCollationIterator(const CollationData *d, UBool numeric, UCharIterator &ui)
  38             : CollationIterator(d, numeric), iter(ui) {}
  39
  40     virtual ~UIterCollationIterator();
  41
  42     virtual void resetToOffset(int32_t newOffset);
  43
  44     virtual int32_t getOffset() const;
  45
  46     virtual UChar32 nextCodePoint(UErrorCode &errorCode);
  47
  48     virtual UChar32 previousCodePoint(UErrorCode &errorCode);
  49
  50 protected:
  51     virtual uint32_t handleNextCE32(UChar32 &c, UErrorCode &errorCode);
  52
  53     virtual UChar handleGetTrailSurrogate();
  54
  55     virtual void forwardNumCodePoints(int32_t num, UErrorCode &errorCode);
  56
  57     virtual void backwardNumCodePoints(int32_t num, UErrorCode &errorCode);
  58
  59     UCharIterator &iter;
  60 };
  61
  62 /**
  63  * Incrementally checks the input text for FCD and normalizes where necessary.
  64  */
  65 class U_I18N_API FCDUIterCollationIterator : public UIterCollationIterator {
  66 public:
  67     FCDUIterCollationIterator(const CollationData *data, UBool numeric, UCharIterator &ui, int32_t startIndex)
  68             : UIterCollationIterator(data, numeric, ui),
  69               state(ITER_CHECK_FWD), start(startIndex),
  70               nfcImpl(data->nfcImpl) {}
  71
  72     virtual ~FCDUIterCollationIterator();
  73
  74     virtual void resetToOffset(int32_t newOffset);
  75
  76     virtual int32_t getOffset() const;
  77
  78     virtual UChar32 nextCodePoint(UErrorCode &errorCode);
  79
  80     virtual UChar32 previousCodePoint(UErrorCode &errorCode);
  81
  82 protected:
  83     virtual uint32_t handleNextCE32(UChar32 &c, UErrorCode &errorCode);
  84
  85     virtual UChar handleGetTrailSurrogate();
  86
  87     virtual void forwardNumCodePoints(int32_t num, UErrorCode &errorCode);
  88
  89     virtual void backwardNumCodePoints(int32_t num, UErrorCode &errorCode);
  90
  91 private:
  92     /**
  93      * Switches to forward checking if possible.
  94      */
  95     void switchToForward();
  96
  97     /**
  98      * Extends the FCD text segment forward or normalizes around pos.
  99      * @return TRUE if success
 100      */
 101     UBool nextSegment(UErrorCode &errorCode);
 102
 103     /**
 104      * Switches to backward checking.
 105      */
 106     void switchToBackward();
 107
 108     /**
 109      * Extends the FCD text segment backward or normalizes around pos.
 110      * @return TRUE if success
 111      */
 112     UBool previousSegment(UErrorCode &errorCode);
 113
 114     UBool normalize(const UnicodeString &s, UErrorCode &errorCode);
 115
 116     enum State {
 117         /**
 118          * The input text [start..(iter index)[ passes the FCD check.
 119          * Moving forward checks incrementally.
 120          * pos & limit are undefined.
 121          */
 122         ITER_CHECK_FWD,
 123         /**
 124          * The input text [(iter index)..limit[ passes the FCD check.
 125          * Moving backward checks incrementally.
 126          * start & pos are undefined.
 127          */
 128         ITER_CHECK_BWD,
 129         /**
 130          * The input text [start..limit[ passes the FCD check.
 131          * pos tracks the current text index.
 132          */
 133         ITER_IN_FCD_SEGMENT,
 134         /**
 135          * The input text [start..limit[ failed the FCD check and was normalized.
 136          * pos tracks the current index in the normalized string.
 137          * The text iterator is at the limit index.
 138          */
 139         IN_NORM_ITER_AT_LIMIT,
 140         /**
 141          * The input text [start..limit[ failed the FCD check and was normalized.
 142          * pos tracks the current index in the normalized string.
 143          * The text iterator is at the start index.
 144          */
 145         IN_NORM_ITER_AT_START
 146     };
 147
 148     State state;
 149
 150     int32_t start;
 151     int32_t pos;
 152     int32_t limit;
 153
 154     const Normalizer2Impl &nfcImpl;
 155     UnicodeString normalized;
 156 };
 157
 158 U_NAMESPACE_END
 159
 160 #endif  // !UCONFIG_NO_COLLATION
 161 #endif  // __UITERCOLLATIONITERATOR_H__