1/*
2*******************************************************************************
3*   Copyright (C) 2010-2012, International Business Machines
4*   Corporation and others.  All Rights Reserved.
5*******************************************************************************
6*   file name:  udicttrie.h
7*   encoding:   US-ASCII
8*   tab size:   8 (not used)
9*   indentation:4
10*
11*   created on: 2010dec17
12*   created by: Markus W. Scherer
13*/
14
15#ifndef __USTRINGTRIE_H__
16#define __USTRINGTRIE_H__
17
18/**
19 * \file
20 * \brief C API: Helper definitions for dictionary trie APIs.
21 */
22
23#include "unicode/utypes.h"
24
25
26/**
27 * Return values for BytesTrie::next(), UCharsTrie::next() and similar methods.
28 * @see USTRINGTRIE_MATCHES
29 * @see USTRINGTRIE_HAS_VALUE
30 * @see USTRINGTRIE_HAS_NEXT
31 * @stable ICU 4.8
32 */
33enum UStringTrieResult {
34    /**
35     * The input unit(s) did not continue a matching string.
36     * Once current()/next() return USTRINGTRIE_NO_MATCH,
37     * all further calls to current()/next() will also return USTRINGTRIE_NO_MATCH,
38     * until the trie is reset to its original state or to a saved state.
39     * @stable ICU 4.8
40     */
41    USTRINGTRIE_NO_MATCH,
42    /**
43     * The input unit(s) continued a matching string
44     * but there is no value for the string so far.
45     * (It is a prefix of a longer string.)
46     * @stable ICU 4.8
47     */
48    USTRINGTRIE_NO_VALUE,
49    /**
50     * The input unit(s) continued a matching string
51     * and there is a value for the string so far.
52     * This value will be returned by getValue().
53     * No further input byte/unit can continue a matching string.
54     * @stable ICU 4.8
55     */
56    USTRINGTRIE_FINAL_VALUE,
57    /**
58     * The input unit(s) continued a matching string
59     * and there is a value for the string so far.
60     * This value will be returned by getValue().
61     * Another input byte/unit can continue a matching string.
62     * @stable ICU 4.8
63     */
64    USTRINGTRIE_INTERMEDIATE_VALUE
65};
66
67/**
68 * Same as (result!=USTRINGTRIE_NO_MATCH).
69 * @param result A result from BytesTrie::first(), UCharsTrie::next() etc.
70 * @return true if the input bytes/units so far are part of a matching string/byte sequence.
71 * @stable ICU 4.8
72 */
73#define USTRINGTRIE_MATCHES(result) ((result)!=USTRINGTRIE_NO_MATCH)
74
75/**
76 * Equivalent to (result==USTRINGTRIE_INTERMEDIATE_VALUE || result==USTRINGTRIE_FINAL_VALUE) but
77 * this macro evaluates result exactly once.
78 * @param result A result from BytesTrie::first(), UCharsTrie::next() etc.
79 * @return true if there is a value for the input bytes/units so far.
80 * @see BytesTrie::getValue
81 * @see UCharsTrie::getValue
82 * @stable ICU 4.8
83 */
84#define USTRINGTRIE_HAS_VALUE(result) ((result)>=USTRINGTRIE_FINAL_VALUE)
85
86/**
87 * Equivalent to (result==USTRINGTRIE_NO_VALUE || result==USTRINGTRIE_INTERMEDIATE_VALUE) but
88 * this macro evaluates result exactly once.
89 * @param result A result from BytesTrie::first(), UCharsTrie::next() etc.
90 * @return true if another input byte/unit can continue a matching string.
91 * @stable ICU 4.8
92 */
93#define USTRINGTRIE_HAS_NEXT(result) ((result)&1)
94
95#endif  /* __USTRINGTRIE_H__ */
96