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Diffstat (limited to 'utf8.c')
| -rw-r--r-- | utf8.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/utf8.c b/utf8.c new file mode 100644 index 0000000000..8fa62571aa --- /dev/null +++ b/utf8.c @@ -0,0 +1,278 @@ +#include "git-compat-util.h" +#include "utf8.h" + +/* This code is originally from http://www.cl.cam.ac.uk/~mgk25/ucs/ */ + +struct interval { + int first; + int last; +}; + +/* auxiliary function for binary search in interval table */ +static int bisearch(wchar_t ucs, const struct interval *table, int max) { + int min = 0; + int mid; + + if (ucs < table[0].first || ucs > table[max].last) + return 0; + while (max >= min) { + mid = (min + max) / 2; + if (ucs > table[mid].last) + min = mid + 1; + else if (ucs < table[mid].first) + max = mid - 1; + else + return 1; + } + + return 0; +} + +/* The following two functions define the column width of an ISO 10646 + * character as follows: + * + * - The null character (U+0000) has a column width of 0. + * + * - Other C0/C1 control characters and DEL will lead to a return + * value of -1. + * + * - Non-spacing and enclosing combining characters (general + * category code Mn or Me in the Unicode database) have a + * column width of 0. + * + * - SOFT HYPHEN (U+00AD) has a column width of 1. + * + * - Other format characters (general category code Cf in the Unicode + * database) and ZERO WIDTH SPACE (U+200B) have a column width of 0. + * + * - Hangul Jamo medial vowels and final consonants (U+1160-U+11FF) + * have a column width of 0. + * + * - Spacing characters in the East Asian Wide (W) or East Asian + * Full-width (F) category as defined in Unicode Technical + * Report #11 have a column width of 2. + * + * - All remaining characters (including all printable + * ISO 8859-1 and WGL4 characters, Unicode control characters, + * etc.) have a column width of 1. + * + * This implementation assumes that wchar_t characters are encoded + * in ISO 10646. + */ + +static int wcwidth(wchar_t ch) +{ + /* + * Sorted list of non-overlapping intervals of non-spacing characters, + * generated by + * "uniset +cat=Me +cat=Mn +cat=Cf -00AD +1160-11FF +200B c". + */ + static const struct interval combining[] = { + { 0x0300, 0x0357 }, { 0x035D, 0x036F }, { 0x0483, 0x0486 }, + { 0x0488, 0x0489 }, { 0x0591, 0x05A1 }, { 0x05A3, 0x05B9 }, + { 0x05BB, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 }, + { 0x05C4, 0x05C4 }, { 0x0600, 0x0603 }, { 0x0610, 0x0615 }, + { 0x064B, 0x0658 }, { 0x0670, 0x0670 }, { 0x06D6, 0x06E4 }, + { 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED }, { 0x070F, 0x070F }, + { 0x0711, 0x0711 }, { 0x0730, 0x074A }, { 0x07A6, 0x07B0 }, + { 0x0901, 0x0902 }, { 0x093C, 0x093C }, { 0x0941, 0x0948 }, + { 0x094D, 0x094D }, { 0x0951, 0x0954 }, { 0x0962, 0x0963 }, + { 0x0981, 0x0981 }, { 0x09BC, 0x09BC }, { 0x09C1, 0x09C4 }, + { 0x09CD, 0x09CD }, { 0x09E2, 0x09E3 }, { 0x0A01, 0x0A02 }, + { 0x0A3C, 0x0A3C }, { 0x0A41, 0x0A42 }, { 0x0A47, 0x0A48 }, + { 0x0A4B, 0x0A4D }, { 0x0A70, 0x0A71 }, { 0x0A81, 0x0A82 }, + { 0x0ABC, 0x0ABC }, { 0x0AC1, 0x0AC5 }, { 0x0AC7, 0x0AC8 }, + { 0x0ACD, 0x0ACD }, { 0x0AE2, 0x0AE3 }, { 0x0B01, 0x0B01 }, + { 0x0B3C, 0x0B3C }, { 0x0B3F, 0x0B3F }, { 0x0B41, 0x0B43 }, + { 0x0B4D, 0x0B4D }, { 0x0B56, 0x0B56 }, { 0x0B82, 0x0B82 }, + { 0x0BC0, 0x0BC0 }, { 0x0BCD, 0x0BCD }, { 0x0C3E, 0x0C40 }, + { 0x0C46, 0x0C48 }, { 0x0C4A, 0x0C4D }, { 0x0C55, 0x0C56 }, + { 0x0CBC, 0x0CBC }, { 0x0CBF, 0x0CBF }, { 0x0CC6, 0x0CC6 }, + { 0x0CCC, 0x0CCD }, { 0x0D41, 0x0D43 }, { 0x0D4D, 0x0D4D }, + { 0x0DCA, 0x0DCA }, { 0x0DD2, 0x0DD4 }, { 0x0DD6, 0x0DD6 }, + { 0x0E31, 0x0E31 }, { 0x0E34, 0x0E3A }, { 0x0E47, 0x0E4E }, + { 0x0EB1, 0x0EB1 }, { 0x0EB4, 0x0EB9 }, { 0x0EBB, 0x0EBC }, + { 0x0EC8, 0x0ECD }, { 0x0F18, 0x0F19 }, { 0x0F35, 0x0F35 }, + { 0x0F37, 0x0F37 }, { 0x0F39, 0x0F39 }, { 0x0F71, 0x0F7E }, + { 0x0F80, 0x0F84 }, { 0x0F86, 0x0F87 }, { 0x0F90, 0x0F97 }, + { 0x0F99, 0x0FBC }, { 0x0FC6, 0x0FC6 }, { 0x102D, 0x1030 }, + { 0x1032, 0x1032 }, { 0x1036, 0x1037 }, { 0x1039, 0x1039 }, + { 0x1058, 0x1059 }, { 0x1160, 0x11FF }, { 0x1712, 0x1714 }, + { 0x1732, 0x1734 }, { 0x1752, 0x1753 }, { 0x1772, 0x1773 }, + { 0x17B4, 0x17B5 }, { 0x17B7, 0x17BD }, { 0x17C6, 0x17C6 }, + { 0x17C9, 0x17D3 }, { 0x17DD, 0x17DD }, { 0x180B, 0x180D }, + { 0x18A9, 0x18A9 }, { 0x1920, 0x1922 }, { 0x1927, 0x1928 }, + { 0x1932, 0x1932 }, { 0x1939, 0x193B }, { 0x200B, 0x200F }, + { 0x202A, 0x202E }, { 0x2060, 0x2063 }, { 0x206A, 0x206F }, + { 0x20D0, 0x20EA }, { 0x302A, 0x302F }, { 0x3099, 0x309A }, + { 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F }, { 0xFE20, 0xFE23 }, + { 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB }, { 0x1D167, 0x1D169 }, + { 0x1D173, 0x1D182 }, { 0x1D185, 0x1D18B }, + { 0x1D1AA, 0x1D1AD }, { 0xE0001, 0xE0001 }, + { 0xE0020, 0xE007F }, { 0xE0100, 0xE01EF } + }; + + /* test for 8-bit control characters */ + if (ch == 0) + return 0; + if (ch < 32 || (ch >= 0x7f && ch < 0xa0)) + return -1; + + /* binary search in table of non-spacing characters */ + if (bisearch(ch, combining, sizeof(combining) + / sizeof(struct interval) - 1)) + return 0; + + /* + * If we arrive here, ch is neither a combining nor a C0/C1 + * control character. + */ + + return 1 + + (ch >= 0x1100 && + /* Hangul Jamo init. consonants */ + (ch <= 0x115f || + ch == 0x2329 || ch == 0x232a || + /* CJK ... Yi */ + (ch >= 0x2e80 && ch <= 0xa4cf && + ch != 0x303f) || + /* Hangul Syllables */ + (ch >= 0xac00 && ch <= 0xd7a3) || + /* CJK Compatibility Ideographs */ + (ch >= 0xf900 && ch <= 0xfaff) || + /* CJK Compatibility Forms */ + (ch >= 0xfe30 && ch <= 0xfe6f) || + /* Fullwidth Forms */ + (ch >= 0xff00 && ch <= 0xff60) || + (ch >= 0xffe0 && ch <= 0xffe6) || + (ch >= 0x20000 && ch <= 0x2fffd) || + (ch >= 0x30000 && ch <= 0x3fffd))); +} + +/* + * This function returns the number of columns occupied by the character + * pointed to by the variable start. The pointer is updated to point at + * the next character. If it was not valid UTF-8, the pointer is set to NULL. + */ +int utf8_width(const char **start) +{ + unsigned char *s = (unsigned char *)*start; + wchar_t ch; + + if (*s < 0x80) { + /* 0xxxxxxx */ + ch = *s; + *start += 1; + } else if ((s[0] & 0xe0) == 0xc0) { + /* 110XXXXx 10xxxxxx */ + if ((s[1] & 0xc0) != 0x80 || + /* overlong? */ + (s[0] & 0xfe) == 0xc0) + goto invalid; + ch = ((s[0] & 0x1f) << 6) | (s[1] & 0x3f); + *start += 2; + } else if ((s[0] & 0xf0) == 0xe0) { + /* 1110XXXX 10Xxxxxx 10xxxxxx */ + if ((s[1] & 0xc0) != 0x80 || + (s[2] & 0xc0) != 0x80 || + /* overlong? */ + (s[0] == 0xe0 && (s[1] & 0xe0) == 0x80) || + /* surrogate? */ + (s[0] == 0xed && (s[1] & 0xe0) == 0xa0) || + /* U+FFFE or U+FFFF? */ + (s[0] == 0xef && s[1] == 0xbf && + (s[2] & 0xfe) == 0xbe)) + goto invalid; + ch = ((s[0] & 0x0f) << 12) | + ((s[1] & 0x3f) << 6) | (s[2] & 0x3f); + *start += 3; + } else if ((s[0] & 0xf8) == 0xf0) { + /* 11110XXX 10XXxxxx 10xxxxxx 10xxxxxx */ + if ((s[1] & 0xc0) != 0x80 || + (s[2] & 0xc0) != 0x80 || + (s[3] & 0xc0) != 0x80 || + /* overlong? */ + (s[0] == 0xf0 && (s[1] & 0xf0) == 0x80) || + /* > U+10FFFF? */ + (s[0] == 0xf4 && s[1] > 0x8f) || s[0] > 0xf4) + goto invalid; + ch = ((s[0] & 0x07) << 18) | ((s[1] & 0x3f) << 12) | + ((s[2] & 0x3f) << 6) | (s[3] & 0x3f); + *start += 4; + } else { +invalid: + *start = NULL; + return 0; + } + + return wcwidth(ch); +} + +int is_utf8(const char *text) +{ + while (*text) { + if (*text == '\n' || *text == '\t' || *text == '\r') { + text++; + continue; + } + utf8_width(&text); + if (!text) + return 0; + } + return 1; +} + +static void print_spaces(int count) +{ + static const char s[] = " "; + while (count >= sizeof(s)) { + fwrite(s, sizeof(s) - 1, 1, stdout); + count -= sizeof(s) - 1; + } + fwrite(s, count, 1, stdout); +} + +/* + * Wrap the text, if necessary. The variable indent is the indent for the + * first line, indent2 is the indent for all other lines. + */ +void print_wrapped_text(const char *text, int indent, int indent2, int width) +{ + int w = indent, assume_utf8 = is_utf8(text); + const char *bol = text, *space = NULL; + + for (;;) { + char c = *text; + if (!c || isspace(c)) { + if (w < width || !space) { + const char *start = bol; + if (space) + start = space; + else + print_spaces(indent); + fwrite(start, text - start, 1, stdout); + if (!c) { + putchar('\n'); + return; + } else if (c == '\t') + w |= 0x07; + space = text; + w++; + text++; + } + else { + putchar('\n'); + text = bol = space + 1; + space = NULL; + w = indent = indent2; + } + continue; + } + if (assume_utf8) + w += utf8_width(&text); + else { + w++; + text++; + } + } +} |