1 // Scintilla source code edit control
2 /** @file UniConversion.h
3 ** Functions to handle UTF-8 and UTF-16 strings.
4 **/
5 // Copyright 1998-2001 by Neil Hodgson <neilh@scintilla.org>
6 // The License.txt file describes the conditions under which this software may be distributed.
7
8 #ifndef UNICONVERSION_H
9 #define UNICONVERSION_H
10
11 namespace Scintilla {
12
13 constexpr int UTF8MaxBytes = 4;
14
15 constexpr int unicodeReplacementChar = 0xFFFD;
16
17 size_t UTF8Length(std::wstring_view wsv) noexcept;
18 size_t UTF8PositionFromUTF16Position(std::string_view u8Text, size_t positionUTF16) noexcept;
19 void UTF8FromUTF16(std::wstring_view wsv, char *putf, size_t len) noexcept;
20 void UTF8FromUTF32Character(int uch, char *putf) noexcept;
21 size_t UTF16Length(std::string_view svu8) noexcept;
22 size_t UTF16FromUTF8(std::string_view svu8, wchar_t *tbuf, size_t tlen);
23 size_t UTF32Length(std::string_view svu8) noexcept;
24 size_t UTF32FromUTF8(std::string_view svu8, unsigned int *tbuf, size_t tlen);
25 // WStringFromUTF8 does the right thing when wchar_t is 2 or 4 bytes so
26 // works on both Windows and Unix.
27 std::wstring WStringFromUTF8(std::string_view svu8);
28 unsigned int UTF16FromUTF32Character(unsigned int val, wchar_t *tbuf) noexcept;
29 bool UTF8IsValid(std::string_view svu8) noexcept;
30 std::string FixInvalidUTF8(const std::string &text);
31
32 extern const unsigned char UTF8BytesOfLead[256];
33
UnicodeFromUTF8(const unsigned char * us)34 inline int UnicodeFromUTF8(const unsigned char *us) noexcept {
35 switch (UTF8BytesOfLead[us[0]]) {
36 case 1:
37 return us[0];
38 case 2:
39 return ((us[0] & 0x1F) << 6) + (us[1] & 0x3F);
40 case 3:
41 return ((us[0] & 0xF) << 12) + ((us[1] & 0x3F) << 6) + (us[2] & 0x3F);
42 default:
43 return ((us[0] & 0x7) << 18) + ((us[1] & 0x3F) << 12) + ((us[2] & 0x3F) << 6) + (us[3] & 0x3F);
44 }
45 }
46
UTF8IsTrailByte(unsigned char ch)47 inline constexpr bool UTF8IsTrailByte(unsigned char ch) noexcept {
48 return (ch >= 0x80) && (ch < 0xc0);
49 }
50
UTF8IsAscii(int ch)51 inline constexpr bool UTF8IsAscii(int ch) noexcept {
52 return ch < 0x80;
53 }
54
55 enum { UTF8MaskWidth=0x7, UTF8MaskInvalid=0x8 };
56 int UTF8Classify(const unsigned char *us, size_t len) noexcept;
UTF8Classify(std::string_view sv)57 inline int UTF8Classify(std::string_view sv) noexcept {
58 return UTF8Classify(reinterpret_cast<const unsigned char *>(sv.data()), sv.length());
59 }
60
61 // Similar to UTF8Classify but returns a length of 1 for invalid bytes
62 // instead of setting the invalid flag
63 int UTF8DrawBytes(const unsigned char *us, int len) noexcept;
64
65 // Line separator is U+2028 \xe2\x80\xa8
66 // Paragraph separator is U+2029 \xe2\x80\xa9
67 constexpr int UTF8SeparatorLength = 3;
UTF8IsSeparator(const unsigned char * us)68 inline bool UTF8IsSeparator(const unsigned char *us) noexcept {
69 return (us[0] == 0xe2) && (us[1] == 0x80) && ((us[2] == 0xa8) || (us[2] == 0xa9));
70 }
71
72 // NEL is U+0085 \xc2\x85
73 constexpr int UTF8NELLength = 2;
UTF8IsNEL(const unsigned char * us)74 inline bool UTF8IsNEL(const unsigned char *us) noexcept {
75 return (us[0] == 0xc2) && (us[1] == 0x85);
76 }
77
78 // Is the sequence of 3 char a UTF-8 line end? Only the last two char are tested for a NEL.
UTF8IsMultibyteLineEnd(unsigned char ch0,unsigned char ch1,unsigned char ch2)79 constexpr bool UTF8IsMultibyteLineEnd(unsigned char ch0, unsigned char ch1, unsigned char ch2) noexcept {
80 return
81 ((ch0 == 0xe2) && (ch1 == 0x80) && ((ch2 == 0xa8) || (ch2 == 0xa9))) ||
82 ((ch1 == 0xc2) && (ch2 == 0x85));
83 }
84
85 enum { SURROGATE_LEAD_FIRST = 0xD800 };
86 enum { SURROGATE_LEAD_LAST = 0xDBFF };
87 enum { SURROGATE_TRAIL_FIRST = 0xDC00 };
88 enum { SURROGATE_TRAIL_LAST = 0xDFFF };
89 enum { SUPPLEMENTAL_PLANE_FIRST = 0x10000 };
90
UTF16CharLength(wchar_t uch)91 inline constexpr unsigned int UTF16CharLength(wchar_t uch) noexcept {
92 return ((uch >= SURROGATE_LEAD_FIRST) && (uch <= SURROGATE_LEAD_LAST)) ? 2 : 1;
93 }
94
UTF16LengthFromUTF8ByteCount(unsigned int byteCount)95 inline constexpr unsigned int UTF16LengthFromUTF8ByteCount(unsigned int byteCount) noexcept {
96 return (byteCount < 4) ? 1 : 2;
97 }
98
99 }
100
101 #endif
102