* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
* USA
*/
+/** @file lib/charset.c @brief Character set conversion */
#include <config.h>
#include "types.h"
#include "configuration.h"
#include "utf8.h"
#include "vector.h"
-
+#include "unidata.h"
+
+/** @brief Low-level converstion routine
+ * @param from Source encoding
+ * @param to Destination encoding
+ * @param ptr First byte to convert
+ * @param n Number of bytes to convert
+ * @return Converted text, 0-terminated; or NULL on error.
+ */
static void *convert(const char *from, const char *to,
const void *ptr, size_t n) {
iconv_t i;
return buf;
}
-/* not everybody's iconv supports UCS-4, and it's inconvenient to have to know
- * our endianness, and it's easy to convert it ourselves, so we do */
-uint32_t *utf82ucs4(const char *mb) {
- struct dynstr_ucs4 d;
- uint32_t c;
-
- dynstr_ucs4_init(&d);
- while(*mb) {
- PARSE_UTF8(mb, c,
- error(0, "invalid UTF-8 sequence"); return 0;);
- dynstr_ucs4_append(&d, c);
- }
- dynstr_ucs4_terminate(&d);
- return d.vec;
-}
-
-char *ucs42utf8(const uint32_t *u) {
- struct dynstr d;
- uint32_t c;
-
- dynstr_init(&d);
- while((c = *u++)) {
- if(c < 0x80)
- dynstr_append(&d, c);
- else if(c < 0x800) {
- dynstr_append(&d, 0xC0 | (c >> 6));
- dynstr_append(&d, 0x80 | (c & 0x3F));
- } else if(c < 0x10000) {
- dynstr_append(&d, 0xE0 | (c >> 12));
- dynstr_append(&d, 0x80 | ((c >> 6) & 0x3F));
- dynstr_append(&d, 0x80 | (c & 0x3F));
- } else if(c < 0x110000) {
- dynstr_append(&d, 0xF0 | (c >> 18));
- dynstr_append(&d, 0x80 | ((c >> 12) & 0x3F));
- dynstr_append(&d, 0x80 | ((c >> 6) & 0x3F));
- dynstr_append(&d, 0x80 | (c & 0x3F));
- } else {
- error(0, "invalid UCS-4 character");
- return 0;
- }
- }
- dynstr_terminate(&d);
- return d.vec;
-}
-
+/** @brief Convert from the local multibyte encoding to UTF-8 */
char *mb2utf8(const char *mb) {
return convert(nl_langinfo(CODESET), "UTF-8", mb, strlen(mb) + 1);
}
+/** @brief Convert from UTF-8 to the local multibyte encoding */
char *utf82mb(const char *utf8) {
return convert("UTF-8", nl_langinfo(CODESET), utf8, strlen(utf8) + 1);
}
+/** @brief Convert from encoding @p from to UTF-8 */
char *any2utf8(const char *from, const char *any) {
return convert(from, "UTF-8", any, strlen(any) + 1);
}
+/** @brief Convert from encoding @p from to the local multibyte encoding */
char *any2mb(const char *from, const char *any) {
if(from) return convert(from, nl_langinfo(CODESET), any, strlen(any) + 1);
else return xstrdup(any);
}
+/** @brief Convert from encoding @p from to encoding @p to */
char *any2any(const char *from,
const char *to,
const char *any) {
else return xstrdup(any);
}
-int ucs4cmp(const uint32_t *a, const uint32_t *b) {
- while(*a && *b && *a == *b) ++a, ++b;
- if(*a > *b) return 1;
- else if(*a < *b) return -1;
- else return 0;
+/** @brief Return nonzero if @p c is a combining character */
+static int combining(int c) {
+ if(c < UNICODE_NCHARS) {
+ const struct unidata *const ud = &unidata[c / UNICODE_MODULUS][c % UNICODE_MODULUS];
+
+ return ud->general_category == unicode_General_Category_Mn || ud->ccc != 0;
+ }
+ /* Assume unknown characters are noncombining */
+ return 0;
+}
+
+/** @brief Truncate a string for display purposes
+ * @param s Pointer to UTF-8 string
+ * @param max Maximum number of columns
+ * @return @p or truncated string (never NULL)
+ *
+ * We don't correctly support bidi or double-width characters yet, nor
+ * locate default grapheme cluster boundaries for saner truncation.
+ */
+const char *truncate_for_display(const char *s, long max) {
+ const char *t = s, *r, *cut = 0;
+ char *truncated;
+ uint32_t c;
+ long n = 0;
+
+ /* We need to discover two things: firstly whether the string is
+ * longer than @p max glyphs and secondly if it is not, where to cut
+ * the string.
+ *
+ * Combining characters follow their base character (unicode
+ * standard 5.0 s2.11), so after each base character we must
+ */
+ while(*t) {
+ PARSE_UTF8(t, c, return s);
+ if(combining(c))
+ /* This must be an initial combining character. We just skip it. */
+ continue;
+ /* So c must be a base character. It may be followed by any
+ * number of combining characters. We advance past them. */
+ do {
+ r = t;
+ PARSE_UTF8(t, c, return s);
+ } while(combining(c));
+ /* Last character wasn't a combining character so back up */
+ t = r;
+ ++n;
+ /* So now there are N glyphs before position T. We might
+ * therefore have reached the cut position. */
+ if(n == max - 3)
+ cut = t;
+ }
+ /* If the string is short enough we return it unmodified */
+ if(n < max)
+ return s;
+ truncated = xmalloc_noptr(cut - s + 4);
+ memcpy(truncated, s, cut - s);
+ strcpy(truncated + (cut - s), "...");
+ return truncated;
}
/*
~mdw / disorder / blobdiff