icuSources/i18n/uitercollationiterator.h

   1 /*
   2 *******************************************************************************
   3 * Copyright (C) 2012-2014, International Business Machines
   4 * Corporation and others.  All Rights Reserved.
   5 *******************************************************************************
   6 * uitercollationiterator.h
   7 *
   8 * created on: 2012sep23 (from utf16collationiterator.h)
   9 * created by: Markus W. Scherer
  10 */
  11
  12 #ifndef __UITERCOLLATIONITERATOR_H__
  13 #define __UITERCOLLATIONITERATOR_H__
  14
  15 #include "unicode/utypes.h"
  16
  17 #if !UCONFIG_NO_COLLATION
  18
  19 #include "unicode/uiter.h"
  20 #include "cmemory.h"
  21 #include "collation.h"
  22 #include "collationdata.h"
  23 #include "normalizer2impl.h"
  24
  25 U_NAMESPACE_BEGIN
  26
  27 /**
  28  * UCharIterator-based collation element and character iterator.
  29  * Handles normalized text inline, with length or NUL-terminated.
  30  * Unnormalized text is handled by a subclass.
  31  */
  32 class U_I18N_API UIterCollationIterator : public CollationIterator {
  33 public:
  34     UIterCollationIterator(const CollationData *d, UBool numeric, UCharIterator &ui)
  35             : CollationIterator(d, numeric), iter(ui) {}
  36
  37     virtual ~UIterCollationIterator();
  38
  39     virtual void resetToOffset(int32_t newOffset);
  40
  41     virtual int32_t getOffset() const;
  42
  43     virtual UChar32 nextCodePoint(UErrorCode &errorCode);
  44
  45     virtual UChar32 previousCodePoint(UErrorCode &errorCode);
  46
  47 protected:
  48     virtual uint32_t handleNextCE32(UChar32 &c, UErrorCode &errorCode);
  49
  50     virtual UChar handleGetTrailSurrogate();
  51
  52     virtual void forwardNumCodePoints(int32_t num, UErrorCode &errorCode);
  53
  54     virtual void backwardNumCodePoints(int32_t num, UErrorCode &errorCode);
  55
  56     UCharIterator &iter;
  57 };
  58
  59 /**
  60  * Incrementally checks the input text for FCD and normalizes where necessary.
  61  */
  62 class U_I18N_API FCDUIterCollationIterator : public UIterCollationIterator {
  63 public:
  64     FCDUIterCollationIterator(const CollationData *data, UBool numeric, UCharIterator &ui, int32_t startIndex)
  65             : UIterCollationIterator(data, numeric, ui),
  66               state(ITER_CHECK_FWD), start(startIndex),
  67               nfcImpl(data->nfcImpl) {}
  68
  69     virtual ~FCDUIterCollationIterator();
  70
  71     virtual void resetToOffset(int32_t newOffset);
  72
  73     virtual int32_t getOffset() const;
  74
  75     virtual UChar32 nextCodePoint(UErrorCode &errorCode);
  76
  77     virtual UChar32 previousCodePoint(UErrorCode &errorCode);
  78
  79 protected:
  80     virtual uint32_t handleNextCE32(UChar32 &c, UErrorCode &errorCode);
  81
  82     virtual UChar handleGetTrailSurrogate();
  83
  84     virtual void forwardNumCodePoints(int32_t num, UErrorCode &errorCode);
  85
  86     virtual void backwardNumCodePoints(int32_t num, UErrorCode &errorCode);
  87
  88 private:
  89     /**
  90      * Switches to forward checking if possible.
  91      */
  92     void switchToForward();
  93
  94     /**
  95      * Extends the FCD text segment forward or normalizes around pos.
  96      * @return TRUE if success
  97      */
  98     UBool nextSegment(UErrorCode &errorCode);
  99
 100     /**
 101      * Switches to backward checking.
 102      */
 103     void switchToBackward();
 104
 105     /**
 106      * Extends the FCD text segment backward or normalizes around pos.
 107      * @return TRUE if success
 108      */
 109     UBool previousSegment(UErrorCode &errorCode);
 110
 111     UBool normalize(const UnicodeString &s, UErrorCode &errorCode);
 112
 113     enum State {
 114         /**
 115          * The input text [start..(iter index)[ passes the FCD check.
 116          * Moving forward checks incrementally.
 117          * pos & limit are undefined.
 118          */
 119         ITER_CHECK_FWD,
 120         /**
 121          * The input text [(iter index)..limit[ passes the FCD check.
 122          * Moving backward checks incrementally.
 123          * start & pos are undefined.
 124          */
 125         ITER_CHECK_BWD,
 126         /**
 127          * The input text [start..limit[ passes the FCD check.
 128          * pos tracks the current text index.
 129          */
 130         ITER_IN_FCD_SEGMENT,
 131         /**
 132          * The input text [start..limit[ failed the FCD check and was normalized.
 133          * pos tracks the current index in the normalized string.
 134          * The text iterator is at the limit index.
 135          */
 136         IN_NORM_ITER_AT_LIMIT,
 137         /**
 138          * The input text [start..limit[ failed the FCD check and was normalized.
 139          * pos tracks the current index in the normalized string.
 140          * The text iterator is at the start index.
 141          */
 142         IN_NORM_ITER_AT_START
 143     };
 144
 145     State state;
 146
 147     int32_t start;
 148     int32_t pos;
 149     int32_t limit;
 150
 151     const Normalizer2Impl &nfcImpl;
 152     UnicodeString normalized;
 153 };
 154
 155 U_NAMESPACE_END
 156
 157 #endif  // !UCONFIG_NO_COLLATION
 158 #endif  // __UITERCOLLATIONITERATOR_H__