Open Chinese Convert: UTF8Util.hpp Source File

Open Chinese Convert 1.0.2 A project for conversion between Traditional and Simplified Chinese

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UTF8Util.hpp
1 /*
2 * Open Chinese Convert
3 *
4 * Copyright 2013 BYVoid <byvoid@byvoid.com>
5 *
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18
19 #pragma once
20
21 #include "Common.hpp"
22
23 namespace opencc {
28 class OPENCC_EXPORT UTF8Util {
29 public:
33 static void SkipUtf8Bom(FILE* fp);
34
39 static size_t NextCharLengthNoException(const char* str) {
40 char ch = *str;
41 if ((ch & 0x80) == 0x00) {
42 return 1;
43 } else if ((ch & 0xE0) == 0xC0) {
44 return 2;
45 } else if ((ch & 0xF0) == 0xE0) {
46 return 3;
47 } else if ((ch & 0xF8) == 0xF0) {
48 return 4;
49 } else if ((ch & 0xFC) == 0xF8) {
50 return 5;
51 } else if ((ch & 0xFE) == 0xFC) {
52 return 6;
53 }
54 return 0;
55 }
56
60 static size_t NextCharLength(const char* str) {
61 size_t length = NextCharLengthNoException(str);
62 if (length == 0) {
63 throw InvalidUTF8(str);
64 }
65 return length;
66 }
67
71 static size_t PrevCharLength(const char* str) {
72 for (size_t i = 1; i <= 6; i++) {
73 str--;
74 size_t length = NextCharLengthNoException(str);
75 if (length == i) {
76 return length;
77 }
78 }
79 throw InvalidUTF8(str);
80 }
81
85 static const char* NextChar(const char* str) {
86 return str + NextCharLength(str);
87 }
88
92 static const char* PrevChar(const char* str) {
93 return str - PrevCharLength(str);
94 }
95
102 static const char* FindNextInline(const char* str, const char ch) {
103 while (!IsLineEndingOrFileEnding(*str) && *str != ch) {
104 str = NextChar(str);
105 }
106 return str;
107 }
108
112 static bool IsLineEndingOrFileEnding(const char ch) {
113 return ch == '\0' || ch == '\n' || ch == '\r';
114 }
115
119 static string FromSubstr(const char* str, size_t length) {
120 string newStr;
121 newStr.resize(length);
122 strncpy(const_cast<char*>(newStr.c_str()), str, length);
123 return newStr;
124 }
125
129 static bool NotShorterThan(const char* str, size_t length) {
130 while (length > 0) {
131 if (*str == '\0') {
132 return false;
133 }
134 length--;
135 str++;
136 }
137 return true;
138 }
139
144 static string TruncateUTF8(const char* str, size_t maxLength) {
145 string wordTrunc;
146 if (NotShorterThan(str, maxLength)) {
147 size_t len = 0;
148 const char* pStr = str;
149 while (len < maxLength) {
150 size_t nextLen = NextCharLength(pStr);
151 pStr += nextLen;
152 len += nextLen;
153 }
154 wordTrunc = FromSubstr(str, len);
155 } else {
156 wordTrunc = str;
157 }
158 return wordTrunc;
159 }
160
164 static void ReplaceAll(string& str, const char* from, const char* to) {
165 string::size_type pos = 0;
166 string::size_type fromLen = strlen(from);
167 string::size_type toLen = strlen(to);
168 while ((pos = str.find(from, pos)) != string::npos) {
169 str.replace(pos, fromLen, to);
170 pos += toLen;
171 }
172 }
173
177 static string Join(const vector<string>& strings, const string& separator) {
178 std::ostringstream buffer;
179 bool first = true;
180 for (const auto& str : strings) {
181 if (!first) {
182 buffer << separator;
183 }
184 buffer << str;
185 first = false;
186 }
187 return buffer.str();
188 }
189
193 static string Join(const vector<string>& strings) {
194 std::ostringstream buffer;
195 for (const auto& str : strings) {
196 buffer << str;
197 }
198 return buffer.str();
199 }
200 };
201 }
opencc::UTF8Util::PrevCharLength
static size_t PrevCharLength(const char *str)
Returns the length in byte for the previous UTF8 character.
Definition: UTF8Util.hpp:71
opencc::UTF8Util::Join
static string Join(const vector< string > &strings)
Joins a string vector in to a string.
Definition: UTF8Util.hpp:193
opencc::InvalidUTF8
Definition: Exception.hpp:85
opencc::UTF8Util::Join
static string Join(const vector< string > &strings, const string &separator)
Joins a string vector in to a string with a separator.
Definition: UTF8Util.hpp:177
opencc::UTF8Util::NotShorterThan
static bool NotShorterThan(const char *str, size_t length)
Returns true if the given string is longer or as long as the given length.
Definition: UTF8Util.hpp:129
opencc::UTF8Util::ReplaceAll
static void ReplaceAll(string &str, const char *from, const char *to)
Replaces all patterns in a string in place.
Definition: UTF8Util.hpp:164
opencc::UTF8Util::FromSubstr
static string FromSubstr(const char *str, size_t length)
Copies a substring with given length to a new std::string.
Definition: UTF8Util.hpp:119
opencc
Definition: BinaryDict.hpp:24
opencc::UTF8Util::PrevChar
static const char * PrevChar(const char *str)
Move the char* pointer before the previous UTF8 character.
Definition: UTF8Util.hpp:92
opencc::UTF8Util::TruncateUTF8
static string TruncateUTF8(const char *str, size_t maxLength)
Truncates a string with a maximal length.
Definition: UTF8Util.hpp:144
opencc::UTF8Util::NextChar
static const char * NextChar(const char *str)
Returns the char* pointer over the next UTF8 character.
Definition: UTF8Util.hpp:85
opencc::UTF8Util
UTF8 string utilities.
Definition: UTF8Util.hpp:28
opencc::UTF8Util::FindNextInline
static const char * FindNextInline(const char *str, const char ch)
Finds a character in the same line.
Definition: UTF8Util.hpp:102
opencc::UTF8Util::NextCharLength
static size_t NextCharLength(const char *str)
Returns the length in byte for the next UTF8 character.
Definition: UTF8Util.hpp:60
opencc::UTF8Util::IsLineEndingOrFileEnding
static bool IsLineEndingOrFileEnding(const char ch)
Returns ture if the character is a line ending or end of file.
Definition: UTF8Util.hpp:112
opencc::UTF8Util::NextCharLengthNoException
static size_t NextCharLengthNoException(const char *str)
Returns the length in byte for the next UTF8 character.
Definition: UTF8Util.hpp:39