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__ */
98