Code Points 1st Byte 2nd Byte 3rd Byte 4th Byte
- U+0000..U+007F 00..7F
- U+0080..U+07FF C2..DF 80..BF
- U+0800..U+0FFF E0 A0..BF 80..BF
- U+1000..U+CFFF E1..EC 80..BF 80..BF
- U+D000..U+D7FF ED 80..9F 80..BF
+ U+0000..U+007F 00..7F
+ U+0080..U+07FF C2..DF 80..BF
+ U+0800..U+0FFF E0 A0..BF 80..BF
+ U+1000..U+CFFF E1..EC 80..BF 80..BF
+ U+D000..U+D7FF ED 80..9F 80..BF
U+D800..U+DFFF ******* ill-formed *******
- U+E000..U+FFFF EE..EF 80..BF 80..BF
+ U+E000..U+FFFF EE..EF 80..BF 80..BF
U+10000..U+3FFFF F0 90..BF 80..BF 80..BF
U+40000..U+FFFFF F1..F3 80..BF 80..BF 80..BF
U+100000..U+10FFFF F4 80..8F 80..BF 80..BF
Note the A0..BF in U+0800..U+0FFF, the 80..9F in U+D000...U+D7FF,
the 90..BF in U+10000..U+3FFFF, and the 80...8F in U+100000..U+10FFFF.
+The "gaps" are caused by legal UTF-8 avoiding non-shortest encodings:
+it is technically possible to UTF-8-encode a single code point in different
+ways, but that is explicitly forbidden, and the shortest possible encoding
+should always be used (and that is what Perl does).
*/
#define UTF8_ALLOW_FE_FF 0x0008
#define UTF8_ALLOW_SHORT 0x0010
#define UTF8_ALLOW_SURROGATE 0x0020
-#define UTF8_ALLOW_BOM 0x0040
-#define UTF8_ALLOW_FFFF 0x0080
-#define UTF8_ALLOW_LONG 0x0100
+#define UTF8_ALLOW_FFFF 0x0040 /* Allows also FFFE. */
+#define UTF8_ALLOW_LONG 0x0080
#define UTF8_ALLOW_ANYUV (UTF8_ALLOW_EMPTY|UTF8_ALLOW_FE_FF|\
- UTF8_ALLOW_SURROGATE|UTF8_ALLOW_BOM|\
+ UTF8_ALLOW_SURROGATE|\
UTF8_ALLOW_FFFF|UTF8_ALLOW_LONG)
-#define UTF8_ALLOW_ANY 0x00ff
+#define UTF8_ALLOW_ANY 0x00FF
#define UTF8_CHECK_ONLY 0x0200
-#define UNICODE_SURROGATE_FIRST 0xd800
-#define UNICODE_SURROGATE_LAST 0xdfff
-#define UNICODE_REPLACEMENT 0xfffd
-#define UNICODE_BYTER_ORDER_MARK 0xfffe
-#define UNICODE_ILLEGAL 0xffff
+#define UNICODE_SURROGATE_FIRST 0xD800
+#define UNICODE_SURROGATE_LAST 0xDFFF
+#define UNICODE_REPLACEMENT 0xFFFD
+#define UNICODE_BYTE_ORDER_MARK 0xFEFF
+#define UNICODE_ILLEGAL 0xFFFF
/* Though our UTF-8 encoding can go beyond this,
- * let's be conservative. */
+ * let's be conservative and do as Unicode 3.2 says. */
#define PERL_UNICODE_MAX 0x10FFFF
#define UNICODE_ALLOW_SURROGATE 0x0001 /* Allow UTF-16 surrogates (EVIL) */
#define UNICODE_ALLOW_FDD0 0x0002 /* Allow the U+FDD0...U+FDEF */
-#define UNICODE_ALLOW_FFFE 0x0004 /* Allow 0xFFFE, 0x1FFFE, ... */
-#define UNICODE_ALLOW_FFFF 0x0008 /* Allow 0xFFFE, 0x1FFFE, ... */
-#define UNICODE_ALLOW_SUPER 0x0010 /* Allow past 10xFFFF */
-#define UNICODE_ALLOW_ANY 0xFFFF
+#define UNICODE_ALLOW_FFFF 0x0004 /* Allow 0xFFF[EF], 0x1FFF[EF], ... */
+#define UNICODE_ALLOW_SUPER 0x0008 /* Allow past 10xFFFF */
+#define UNICODE_ALLOW_ANY 0x000F
#define UNICODE_IS_SURROGATE(c) ((c) >= UNICODE_SURROGATE_FIRST && \
(c) <= UNICODE_SURROGATE_LAST)
#define UNICODE_IS_REPLACEMENT(c) ((c) == UNICODE_REPLACEMENT)
-#define UNICODE_IS_BYTE_ORDER_MARK(c) ((c) == UNICODE_BYTER_ORDER_MARK)
+#define UNICODE_IS_BYTE_ORDER_MARK(c) ((c) == UNICODE_BYTE_ORDER_MARK)
#define UNICODE_IS_ILLEGAL(c) ((c) == UNICODE_ILLEGAL)
#ifdef HAS_QUAD