icuSources/common/unicode/ustringtrie.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) 2010-2012, International Business Machines
   6 *   Corporation and others.  All Rights Reserved.
   7 *******************************************************************************
   8 *   file name:  udicttrie.h
   9 *   encoding:   UTF-8
  10 *   tab size:   8 (not used)
  11 *   indentation:4
  12 *
  13 *   created on: 2010dec17
  14 *   created by: Markus W. Scherer
  15 */
  16
  17 #ifndef __USTRINGTRIE_H__
  18 #define __USTRINGTRIE_H__
  19
  20 /**
  21  * \file
  22  * \brief C API: Helper definitions for dictionary trie APIs.
  23  */
  24
  25 #include "unicode/utypes.h"
  26
  27
  28 /**
  29  * Return values for BytesTrie::next(), UCharsTrie::next() and similar methods.
  30  * @see USTRINGTRIE_MATCHES
  31  * @see USTRINGTRIE_HAS_VALUE
  32  * @see USTRINGTRIE_HAS_NEXT
  33  * @stable ICU 4.8
  34  */
  35 enum UStringTrieResult {
  36     /**
  37      * The input unit(s) did not continue a matching string.
  38      * Once current()/next() return USTRINGTRIE_NO_MATCH,
  39      * all further calls to current()/next() will also return USTRINGTRIE_NO_MATCH,
  40      * until the trie is reset to its original state or to a saved state.
  41      * @stable ICU 4.8
  42      */
  43     USTRINGTRIE_NO_MATCH,
  44     /**
  45      * The input unit(s) continued a matching string
  46      * but there is no value for the string so far.
  47      * (It is a prefix of a longer string.)
  48      * @stable ICU 4.8
  49      */
  50     USTRINGTRIE_NO_VALUE,
  51     /**
  52      * The input unit(s) continued a matching string
  53      * and there is a value for the string so far.
  54      * This value will be returned by getValue().
  55      * No further input byte/unit can continue a matching string.
  56      * @stable ICU 4.8
  57      */
  58     USTRINGTRIE_FINAL_VALUE,
  59     /**
  60      * The input unit(s) continued a matching string
  61      * and there is a value for the string so far.
  62      * This value will be returned by getValue().
  63      * Another input byte/unit can continue a matching string.
  64      * @stable ICU 4.8
  65      */
  66     USTRINGTRIE_INTERMEDIATE_VALUE
  67 };
  68
  69 /**
  70  * Same as (result!=USTRINGTRIE_NO_MATCH).
  71  * @param result A result from BytesTrie::first(), UCharsTrie::next() etc.
  72  * @return true if the input bytes/units so far are part of a matching string/byte sequence.
  73  * @stable ICU 4.8
  74  */
  75 #define USTRINGTRIE_MATCHES(result) ((result)!=USTRINGTRIE_NO_MATCH)
  76
  77 /**
  78  * Equivalent to (result==USTRINGTRIE_INTERMEDIATE_VALUE || result==USTRINGTRIE_FINAL_VALUE) but
  79  * this macro evaluates result exactly once.
  80  * @param result A result from BytesTrie::first(), UCharsTrie::next() etc.
  81  * @return true if there is a value for the input bytes/units so far.
  82  * @see BytesTrie::getValue
  83  * @see UCharsTrie::getValue
  84  * @stable ICU 4.8
  85  */
  86 #define USTRINGTRIE_HAS_VALUE(result) ((result)>=USTRINGTRIE_FINAL_VALUE)
  87
  88 /**
  89  * Equivalent to (result==USTRINGTRIE_NO_VALUE || result==USTRINGTRIE_INTERMEDIATE_VALUE) but
  90  * this macro evaluates result exactly once.
  91  * @param result A result from BytesTrie::first(), UCharsTrie::next() etc.
  92  * @return true if another input byte/unit can continue a matching string.
  93  * @stable ICU 4.8
  94  */
  95 #define USTRINGTRIE_HAS_NEXT(result) ((result)&1)
  96
  97 #endif  /* __USTRINGTRIE_H__ */