1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
|
// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
////////////////////////////////////////////////////////////////////////////
//
//
// Purpose:
//
//
////////////////////////////////////////////////////////////////////////////
using System.Collections;
using System.Diagnostics;
using System.Runtime.Serialization;
namespace System.Globalization
{
//
// This is public because GetTextElement() is public.
//
[Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public class TextElementEnumerator : IEnumerator
{
private String _str;
private int _index;
private int _startIndex;
[NonSerialized]
private int _strLen; // This is the length of the total string, counting from the beginning of string.
[NonSerialized]
private int _currTextElementLen; // The current text element lenght after MoveNext() is called.
[OptionalField(VersionAdded = 2)]
private UnicodeCategory _uc;
[OptionalField(VersionAdded = 2)]
private int _charLen; // The next abstract char to look at after MoveNext() is called. It could be 1 or 2, depending on if it is a surrogate or not.
internal TextElementEnumerator(String str, int startIndex, int strLen)
{
Debug.Assert(str != null, "TextElementEnumerator(): str != null");
Debug.Assert(startIndex >= 0 && strLen >= 0, "TextElementEnumerator(): startIndex >= 0 && strLen >= 0");
Debug.Assert(strLen >= startIndex, "TextElementEnumerator(): strLen >= startIndex");
_str = str;
_startIndex = startIndex;
_strLen = strLen;
Reset();
}
// the following fields is defined to keep the compatibility with Everett.
// don't change/remove the names/types of these fields.
private int _endIndex;
private int _nextTextElementLen;
[OnDeserializing]
private void OnDeserializing(StreamingContext ctx)
{
_charLen = -1;
}
[OnDeserialized]
private void OnDeserialized(StreamingContext ctx)
{
_strLen = _endIndex + 1;
_currTextElementLen = _nextTextElementLen;
if (_charLen == -1)
{
_uc = CharUnicodeInfo.InternalGetUnicodeCategory(_str, _index, out _charLen);
}
}
[OnSerializing]
private void OnSerializing(StreamingContext ctx)
{
_endIndex = _strLen - 1;
_nextTextElementLen = _currTextElementLen;
}
public bool MoveNext()
{
if (_index >= _strLen)
{
// Make the _index to be greater than _strLen so that we can throw exception if GetTextElement() is called.
_index = _strLen + 1;
return (false);
}
_currTextElementLen = StringInfo.GetCurrentTextElementLen(_str, _index, _strLen, ref _uc, ref _charLen);
_index += _currTextElementLen;
return (true);
}
//
// Get the current text element.
//
public Object Current
{
get
{
return (GetTextElement());
}
}
//
// Get the current text element.
//
public String GetTextElement()
{
if (_index == _startIndex)
{
throw new InvalidOperationException(SR.InvalidOperation_EnumNotStarted);
}
if (_index > _strLen)
{
throw new InvalidOperationException(SR.InvalidOperation_EnumEnded);
}
return (_str.Substring(_index - _currTextElementLen, _currTextElementLen));
}
//
// Get the starting index of the current text element.
//
public int ElementIndex
{
get
{
if (_index == _startIndex)
{
throw new InvalidOperationException(SR.InvalidOperation_EnumNotStarted);
}
return (_index - _currTextElementLen);
}
}
public void Reset()
{
_index = _startIndex;
if (_index < _strLen)
{
// If we have more than 1 character, get the category of the current char.
_uc = CharUnicodeInfo.InternalGetUnicodeCategory(_str, _index, out _charLen);
}
}
}
}
|
