libbb: better unicode width support. Hopefully fixes bug 839.

Also opens up a possibility to make other unicode stuff smaller
and more correct later. but:

function                                             old     new   delta
static.combining                                       -     516    +516
bb_wcwidth                                             -     328    +328
unicode_cut_nchars                                     -     141    +141
mbstowc_internal                                       -      93     +93
in_table                                               -      78     +78
cal_main                                             899     961     +62
static.combining0x10000                                -      40     +40
unicode_strlen                                         -      31     +31
bb_mbstrlen                                           31       -     -31
bb_mbstowcs                                          173     102     -71
------------------------------------------------------------------------------
(add/remove: 7/1 grow/shrink: 1/1 up/down: 1289/-102)        Total: 1187 bytes

Uses code of Markus Kuhn, which is in public domain:
http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
"Permission to use, copy, modify, and distribute this software
 for any purpose and without fee is hereby granted. The author
 disclaims all warranties with regard to this software."

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

3 files changed, 372 insertions, 59 deletions

diff --git a/libbb/lineedit.c b/libbb/lineedit.c
index b73f1d6da..c50b31d67 100644
--- a/libbb/lineedit.c
+++ b/libbb/lineedit.c
@@ -878,7 +878,7 @@ static void showfiles(void)
 
         /* find the longest file name - use that as the column width */
         for (row = 0; row < nrows; row++) {
-                l = bb_mbstrlen(matches[row]);
+                l = unicode_strlen(matches[row]);
                 if (column_width < l)
                         column_width = l;
         }
@@ -898,7 +898,7 @@ static void showfiles(void)
 
                 for (nc = 1; nc < ncols && n+nrows < nfiles; n += nrows, nc++) {
                         printf("%s%-*s", matches[n],
-                                (int)(column_width - bb_mbstrlen(matches[n])), ""
+                                (int)(column_width - unicode_strlen(matches[n])), ""
                         );
                 }
                 puts(matches[n]);
diff --git a/libbb/unicode.c b/libbb/unicode.c
index 80042957c..844c154e0 100644
--- a/libbb/unicode.c
+++ b/libbb/unicode.c
@@ -9,22 +9,19 @@
 #include "libbb.h"
 #include "unicode.h"
 
-/* If it's not a constant... */
+/* If it's not #defined as a constant in unicode.h... */
 #ifndef unicode_status
 uint8_t unicode_status;
 #endif
 
-size_t FAST_FUNC bb_mbstrlen(const char *string)
-{
-        size_t width = mbstowcs(NULL, string, INT_MAX);
-        if (width == (size_t)-1L)
-                return strlen(string);
-        return width;
-}
+/* This file is compiled only if FEATURE_ASSUME_UNICODE is on.
+ * We check other options and decide whether to use libc support
+ * via locale, or use our own logic:
+ */
 
 #if ENABLE_LOCALE_SUPPORT
 
-/* Unicode support using libc */
+/* Unicode support using libc locale support. */
 
 void FAST_FUNC init_unicode(void)
 {
@@ -34,12 +31,12 @@ void FAST_FUNC init_unicode(void)
         if (unicode_status != UNICODE_UNKNOWN)
                 return;
 
-        unicode_status = bb_mbstrlen(unicode_0x394) == 1 ? UNICODE_ON : UNICODE_OFF;
+        unicode_status = unicode_strlen(unicode_0x394) == 1 ? UNICODE_ON : UNICODE_OFF;
 }
 
 #else
 
-/* Crude "locale support" which knows only C and Unicode locales */
+/* Homegrown Unicode support. It knows only C and Unicode locales. */
 
 # if ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
 void FAST_FUNC init_unicode(void)
@@ -93,7 +90,6 @@ static size_t wcrtomb_internal(char *s, wchar_t wc)
         s[0] = wc | (uint8_t)(0x3f00 >> n);
         return n;
 }
-
 size_t FAST_FUNC wcrtomb(char *s, wchar_t wc, mbstate_t *ps UNUSED_PARAM)
 {
         if (unicode_status != UNICODE_ON) {
@@ -103,7 +99,6 @@ size_t FAST_FUNC wcrtomb(char *s, wchar_t wc, mbstate_t *ps UNUSED_PARAM)
 
         return wcrtomb_internal(s, wc);
 }
-
 size_t FAST_FUNC wcstombs(char *dest, const wchar_t *src, size_t n)
 {
         size_t org_n = n;
@@ -144,6 +139,51 @@ size_t FAST_FUNC wcstombs(char *dest, const wchar_t *src, size_t n)
         return org_n - n;
 }
 
+static const char *mbstowc_internal(wchar_t *res, const char *src)
+{
+        int bytes;
+        unsigned c = (unsigned char) *src++;
+
+        if (c <= 0x7f) {
+                *res = c;
+                return src;
+        }
+
+        /* 80-7FF -> 110yyyxx 10xxxxxx */
+        /* 800-FFFF -> 1110yyyy 10yyyyxx 10xxxxxx */
+        /* 10000-1FFFFF -> 11110zzz 10zzyyyy 10yyyyxx 10xxxxxx */
+        /* 200000-3FFFFFF -> 111110tt 10zzzzzz 10zzyyyy 10yyyyxx 10xxxxxx */
+        /* 4000000-FFFFFFFF -> 111111tt 10tttttt 10zzzzzz 10zzyyyy 10yyyyxx 10xxxxxx */
+        bytes = 0;
+        do {
+                c <<= 1;
+                bytes++;
+        } while ((c & 0x80) && bytes < 6);
+        if (bytes == 1)
+                return NULL;
+        c = (uint8_t)(c) >> bytes;
+
+        while (--bytes) {
+                unsigned ch = (unsigned char) *src++;
+                if ((ch & 0xc0) != 0x80) {
+                        return NULL;
+                }
+                c = (c << 6) + (ch & 0x3f);
+        }
+
+        /* TODO */
+        /* Need to check that c isn't produced by overlong encoding */
+        /* Example: 11000000 10000000 converts to NUL */
+        /* 11110000 10000000 10000100 10000000 converts to 0x100 */
+        /* correct encoding: 11000100 10000000 */
+        if (c <= 0x7f) { /* crude check */
+                return NULL;
+                //or maybe 0xfffd; /* replacement character */
+        }
+
+        *res = c;
+        return src;
+}
 size_t FAST_FUNC mbstowcs(wchar_t *dest, const char *src, size_t n)
 {
         size_t org_n = n;
@@ -162,58 +202,20 @@ size_t FAST_FUNC mbstowcs(wchar_t *dest, const char *src, size_t n)
         }
 
         while (n) {
-                int bytes;
-                unsigned c = (unsigned char) *src++;
-
-                if (c <= 0x7f) {
-                        if (dest)
-                                *dest++ = c;
-                        if (c == '\0')
-                                break;
-                        n--;
-                        continue;
-                }
-
-                /* 80-7FF -> 110yyyxx 10xxxxxx */
-                /* 800-FFFF -> 1110yyyy 10yyyyxx 10xxxxxx */
-                /* 10000-1FFFFF -> 11110zzz 10zzyyyy 10yyyyxx 10xxxxxx */
-                /* 200000-3FFFFFF -> 111110tt 10zzzzzz 10zzyyyy 10yyyyxx 10xxxxxx */
-                /* 4000000-FFFFFFFF -> 111111tt 10tttttt 10zzzzzz 10zzyyyy 10yyyyxx 10xxxxxx */
-                bytes = 0;
-                do {
-                        c <<= 1;
-                        bytes++;
-                } while ((c & 0x80) && bytes < 6);
-                if (bytes == 1)
+                wchar_t wc;
+                const char *rc = mbstowc_internal(dest ? dest : &wc, src);
+                if (rc == NULL) /* error */
                         return (size_t) -1L;
-                c = (uint8_t)(c) >> bytes;
-
-                while (--bytes) {
-                        unsigned ch = (unsigned char) *src++;
-                        if ((ch & 0xc0) != 0x80) {
-                                return (size_t) -1L;
-                        }
-                        c = (c << 6) + (ch & 0x3f);
-                }
-
-                /* TODO */
-                /* Need to check that c isn't produced by overlong encoding */
-                /* Example: 11000000 10000000 converts to NUL */
-                /* 11110000 10000000 10000100 10000000 converts to 0x100 */
-                /* correct encoding: 11000100 10000000 */
-                if (c <= 0x7f) { /* crude check */
-                        return (size_t) -1L;
-                        //or maybe: c = 0xfffd; /* replacement character */
-                }
-
                 if (dest)
-                        *dest++ = c;
+                        dest++;
                 n--;
         }
 
         return org_n - n;
 }
 
+#include "unicode_wcwidth.c"
+
 int FAST_FUNC iswspace(wint_t wc)
 {
         return (unsigned)wc <= 0x7f && isspace(wc);
@@ -229,4 +231,98 @@ int FAST_FUNC iswpunct(wint_t wc)
         return (unsigned)wc <= 0x7f && ispunct(wc);
 }
 
+#endif /* Homegrown Unicode support */
+
+
+/* The rest is mostly same for libc and for "homegrown" support */
+
+size_t FAST_FUNC unicode_strlen(const char *string)
+{
+        size_t width = mbstowcs(NULL, string, INT_MAX);
+        if (width == (size_t)-1L)
+                return strlen(string);
+        return width;
+}
+
+char* FAST_FUNC unicode_cut_nchars(unsigned width, const char *src)
+{
+        char *dst;
+        unsigned dst_len;
+
+        if (unicode_status != UNICODE_ON)
+                return xasprintf("%-*.*s", width, width, src);
+
+        dst = NULL;
+        dst_len = 0;
+        while (1) {
+                int w;
+                wchar_t wc;
+
+                dst = xrealloc(dst, dst_len + 2 * MB_CUR_MAX);
+#if ENABLE_LOCALE_SUPPORT
+                {
+                        mbstate_t mbst = { 0 };
+                        ssize_t rc = mbsrtowcs(&wc, &src, 1, &mbst);
+                        if (rc <= 0) /* error, or end-of-string */
+                                break;
+                }
+#else
+                src = mbstowc_internal(&wc, src);
+                if (!src || wc == 0) /* error, or end-of-string */
+                        break;
 #endif
+                w = wcwidth(wc);
+                if (w < 0) /* non-printable wchar */
+                        break;
+                width -= w;
+                if ((int)width < 0) { /* string is longer than width */
+                        width += w;
+                        while (width) {
+                                dst[dst_len++] = ' ';
+                                width--;
+                        }
+                        break;
+                }
+#if ENABLE_LOCALE_SUPPORT
+                {
+                        mbstate_t mbst = { 0 };
+                        dst_len += wcrtomb(&dst[dst_len], wc, &mbst);
+                }
+#else
+                dst_len += wcrtomb_internal(&dst[dst_len], wc);
+#endif
+        }
+        dst[dst_len] = '\0';
+        return dst;
+}
+
+unsigned FAST_FUNC unicode_padding_to_width(unsigned width, const char *src)
+{
+        if (unicode_status != UNICODE_ON) {
+                return width - strnlen(src, width);
+        }
+
+        while (1) {
+                int w;
+                wchar_t wc;
+
+#if ENABLE_LOCALE_SUPPORT
+                {
+                        mbstate_t mbst = { 0 };
+                        ssize_t rc = mbsrtowcs(&wc, &src, 1, &mbst);
+                        if (rc <= 0) /* error, or end-of-string */
+                                return width;
+                }
+#else
+                src = mbstowc_internal(&wc, src);
+                if (!src || wc == 0) /* error, or end-of-string */
+                        return width;
+#endif
+                w = wcwidth(wc);
+                if (w < 0) /* non-printable wchar */
+                        return width;
+                width -= w;
+                if ((int)width <= 0) /* string is longer than width */
+                        return 0;
+        }
+}
diff --git a/libbb/unicode_wcwidth.c b/libbb/unicode_wcwidth.c
new file mode 100644
index 000000000..515c084c1
--- /dev/null
+++ b/libbb/unicode_wcwidth.c
@@ -0,0 +1,217 @@
+/*
+ * This is an implementation of wcwidth() and wcswidth() (defined in
+ * IEEE Std 1002.1-2001) for Unicode.
+ *
+ * http://www.opengroup.org/onlinepubs/007904975/functions/wcwidth.html
+ * http://www.opengroup.org/onlinepubs/007904975/functions/wcswidth.html
+ *
+ * In fixed-width output devices, Latin characters all occupy a single
+ * "cell" position of equal width, whereas ideographic CJK characters
+ * occupy two such cells. Interoperability between terminal-line
+ * applications and (teletype-style) character terminals using the
+ * UTF-8 encoding requires agreement on which character should advance
+ * the cursor by how many cell positions. No established formal
+ * standards exist at present on which Unicode character shall occupy
+ * how many cell positions on character terminals. These routines are
+ * a first attempt of defining such behavior based on simple rules
+ * applied to data provided by the Unicode Consortium.
+ *
+ * For some graphical characters, the Unicode standard explicitly
+ * defines a character-cell width via the definition of the East Asian
+ * FullWidth (F), Wide (W), Half-width (H), and Narrow (Na) classes.
+ * In all these cases, there is no ambiguity about which width a
+ * terminal shall use. For characters in the East Asian Ambiguous (A)
+ * class, the width choice depends purely on a preference of backward
+ * compatibility with either historic CJK or Western practice.
+ * Choosing single-width for these characters is easy to justify as
+ * the appropriate long-term solution, as the CJK practice of
+ * displaying these characters as double-width comes from historic
+ * implementation simplicity (8-bit encoded characters were displayed
+ * single-width and 16-bit ones double-width, even for Greek,
+ * Cyrillic, etc.) and not any typographic considerations.
+ *
+ * Much less clear is the choice of width for the Not East Asian
+ * (Neutral) class. Existing practice does not dictate a width for any
+ * of these characters. It would nevertheless make sense
+ * typographically to allocate two character cells to characters such
+ * as for instance EM SPACE or VOLUME INTEGRAL, which cannot be
+ * represented adequately with a single-width glyph. The following
+ * routines at present merely assign a single-cell width to all
+ * neutral characters, in the interest of simplicity. This is not
+ * entirely satisfactory and should be reconsidered before
+ * establishing a formal standard in this area. At the moment, the
+ * decision which Not East Asian (Neutral) characters should be
+ * represented by double-width glyphs cannot yet be answered by
+ * applying a simple rule from the Unicode database content. Setting
+ * up a proper standard for the behavior of UTF-8 character terminals
+ * will require a careful analysis not only of each Unicode character,
+ * but also of each presentation form, something the author of these
+ * routines has avoided to do so far.
+ *
+ * http://www.unicode.org/unicode/reports/tr11/
+ *
+ * Markus Kuhn -- 2007-05-26 (Unicode 5.0)
+ *
+ * Permission to use, copy, modify, and distribute this software
+ * for any purpose and without fee is hereby granted. The author
+ * disclaims all warranties with regard to this software.
+ *
+ * Latest version: http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
+ */
+
+struct interval {
+        uint16_t first;
+        uint16_t last;
+};
+
+/* auxiliary function for binary search in interval table */
+static int in_table(unsigned ucs, const struct interval *table, unsigned max)
+{
+        unsigned min = 0;
+        unsigned 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(unsigned ucs)
+{
+        /* 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, 0x0486 }, { 0x0488, 0x0489 },
+                { 0x0591, 0x05BD }, { 0x05BF, 0x05BF }, { 0x05C1, 0x05C2 },
+                { 0x05C4, 0x05C5 }, { 0x05C7, 0x05C7 }, { 0x0600, 0x0603 },
+                { 0x0610, 0x0615 }, { 0x064B, 0x065E }, { 0x0670, 0x0670 },
+                { 0x06D6, 0x06E4 }, { 0x06E7, 0x06E8 }, { 0x06EA, 0x06ED },
+                { 0x070F, 0x070F }, { 0x0711, 0x0711 }, { 0x0730, 0x074A },
+                { 0x07A6, 0x07B0 }, { 0x07EB, 0x07F3 }, { 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 },
+                { 0x0CE2, 0x0CE3 }, { 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 }, { 0x135F, 0x135F },
+                { 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 },
+                { 0x1A17, 0x1A18 }, { 0x1B00, 0x1B03 }, { 0x1B34, 0x1B34 },
+                { 0x1B36, 0x1B3A }, { 0x1B3C, 0x1B3C }, { 0x1B42, 0x1B42 },
+                { 0x1B6B, 0x1B73 }, { 0x1DC0, 0x1DCA }, { 0x1DFE, 0x1DFF },
+                { 0x200B, 0x200F }, { 0x202A, 0x202E }, { 0x2060, 0x2063 },
+                { 0x206A, 0x206F }, { 0x20D0, 0x20EF }, { 0x302A, 0x302F },
+                { 0x3099, 0x309A }, { 0xA806, 0xA806 }, { 0xA80B, 0xA80B },
+                { 0xA825, 0xA826 }, { 0xFB1E, 0xFB1E }, { 0xFE00, 0xFE0F },
+                { 0xFE20, 0xFE23 }, { 0xFEFF, 0xFEFF }, { 0xFFF9, 0xFFFB }
+        };
+        static const struct interval combining0x10000[] = {
+                { 0x0A01, 0x0A03 }, { 0x0A05, 0x0A06 }, { 0x0A0C, 0x0A0F },
+                { 0x0A38, 0x0A3A }, { 0x0A3F, 0x0A3F }, { 0xD167, 0xD169 },
+                { 0xD173, 0xD182 }, { 0xD185, 0xD18B }, { 0xD1AA, 0xD1AD },
+                { 0xD242, 0xD244 }
+        };
+
+        if (ucs == 0)
+                return 0;
+        /* test for 8-bit control characters (00-1f, 80-9f, 7f) */
+        if ((ucs & ~0x80) < 0x20 || ucs == 0x7f)
+                return -1;
+        if (ucs < 0x0300) /* optimization */
+                return 1;
+
+        /* binary search in table of non-spacing characters */
+        if (in_table(ucs, combining, ARRAY_SIZE(combining) - 1))
+                return 0;
+
+        if (ucs < 0x1100) /* optimization */
+                return 1;
+
+        /* binary search in table of non-spacing characters, cont. */
+        if (in_table(ucs ^ 0x10000, combining0x10000, ARRAY_SIZE(combining0x10000) - 1))
+                return 0;
+        if (ucs == 0xE0001
+         || (ucs >= 0xE0020 && ucs <= 0xE007F)
+         || (ucs >= 0xE0100 && ucs <= 0xE01EF)
+        ) {
+                return 0;
+        }
+
+        /* if we arrive here, ucs is not a combining or C0/C1 control character */
+
+        return 1 +
+                (  (/*ucs >= 0x1100 &&*/ ucs <= 0x115f) /* Hangul Jamo init. consonants */
+                || ucs == 0x2329
+                || ucs == 0x232a
+                || (ucs >= 0x2e80 && ucs <= 0xa4cf && ucs != 0x303f) /* CJK ... Yi */
+                || (ucs >= 0xac00 && ucs <= 0xd7a3) /* Hangul Syllables */
+                || (ucs >= 0xf900 && ucs <= 0xfaff) /* CJK Compatibility Ideographs */
+                || (ucs >= 0xfe10 && ucs <= 0xfe19) /* Vertical forms */
+                || (ucs >= 0xfe30 && ucs <= 0xfe6f) /* CJK Compatibility Forms */
+                || (ucs >= 0xff00 && ucs <= 0xff60) /* Fullwidth Forms */
+                || (ucs >= 0xffe0 && ucs <= 0xffe6)
+                || (ucs >= 0x20000 && ucs <= 0x2fffd)
+                || (ucs >= 0x30000 && ucs <= 0x3fffd)
+                );
+}