utf8: make it easier to auto-update git_wcwidth()

The function git_wcwidth() returns for a given unicode code point the
width on the display:

 -1 for control characters,
  0 for combining or other non-visible code points
  1 for e.g. ASCII
  2 for double-width code points.

This table had been originally been extracted for one Unicode
version, probably 3.2.

We now use two tables these days, one for zero-width and another for
double-width.  Make it easier to update these tables to a later
version of Unicode by factoring out the table from utf8.c into
unicode_width.h and add the script update_unicode.sh to update the
table based on the latest Unicode specification files.

Thanks to Peter Krefting <peter@softwolves.pp.se> and Kevin Bracey
<kevin@bracey.fi> for helping with their Unicode knowledge.

Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 59 deletions

diff --git a/utf8.c b/utf8.c
index 5134552..db7ef3c 100644
--- a/utf8.c
+++ b/utf8.c
@@ -80,65 +80,8 @@ static int git_wcwidth(ucs_char_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, 0x036F }, { 0x0483, 0x0489 }, { 0x0591, 0x05BD },
-		{ 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 }, { 0x05C4, 0x05C5 },
-		{ 0x05C7, 0x05C7 }, { 0x0600, 0x0604 }, { 0x0610, 0x061A },
-		{ 0x064B, 0x065F }, { 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 }
-	};
-	static const struct interval double_width[] = {
-		{ 0x1100, 0x115F },
-		{ 0x2329, 0x232A },
-		{ 0x2E80, 0x303E },
-		{ 0x3040, 0xA4CF },
-		{ 0xAC00, 0xD7A3 },
-		{ 0xF900, 0xFAFF },
-		{ 0xFE30, 0xFE6F },
-		{ 0xFF00, 0xFF60 },
-		{ 0xFFE0, 0xFFE6 },
-		{ 0x20000, 0x2FFFD },
-		{ 0x30000, 0x3FFFD }
-	};
+#include "unicode_width.h"
 
 	/* test for 8-bit control characters */
 	if (ch == 0)
@@ -147,7 +90,7 @@ static int git_wcwidth(ucs_char_t ch)
 		return -1;
 
 	/* binary search in table of non-spacing characters */
-	if (bisearch(ch, combining, sizeof(combining)
+	if (bisearch(ch, zero_width, sizeof(zero_width)
 				/ sizeof(struct interval) - 1))
 		return 0;