diff options
Diffstat (limited to 'utf8.h')
| -rw-r--r-- | utf8.h | 25 |
1 files changed, 18 insertions, 7 deletions
@@ -826,13 +826,24 @@ case any call to string overloading updates the internal UTF-8 encoding flag. =for apidoc Am|STRLEN|isUTF8_CHAR|const U8 *s|const U8 *e -Returns the number of bytes beginning at C<s> which form a legal UTF-8 (or -UTF-EBCDIC) encoded character, looking no further than S<C<e - s>> bytes into -C<s>. Returns 0 if the sequence starting at C<s> through S<C<e - 1>> is not -well-formed UTF-8. +Evaluates to non-zero if the first few bytes of the string starting at C<s> and +looking no further than S<C<e - 1>> are well-formed UTF-8 that represents some +code point; otherwise it evaluates to 0. If non-zero, the value gives how many +many bytes starting at C<s> comprise the code point's representation. -Note that an INVARIANT character (i.e. ASCII on non-EBCDIC -machines) is a valid UTF-8 character. +The code point can be any that will fit in a UV on this machine, using Perl's +extension to official UTF-8 to represent those higher than the Unicode maximum +of 0x10FFFF. That means that this macro is used to efficiently decide if the +next few bytes in C<s> is legal UTF-8 for a single character. Use +L</is_utf8_string>(), L</is_utf8_string_loclen>(), and +L</is_utf8_string_loc>() to check entire strings. + +Note that it is deprecated to use code points higher than what will fit in an +IV. This macro does not raise any warnings for such code points, treating them +as valid. + +Note also that a UTF-8 INVARIANT character (i.e. ASCII on non-EBCDIC machines) +is a valid UTF-8 character. =cut */ @@ -845,7 +856,7 @@ machines) is a valid UTF-8 character. ? 0 \ : LIKELY(IS_UTF8_CHAR_FAST(UTF8SKIP(s))) \ ? is_UTF8_CHAR_utf8_no_length_checks(s) \ - : _is_utf8_char_slow(s, e)) + : _is_utf8_char_slow(s, UTF8SKIP(s))) #define is_utf8_char_buf(buf, buf_end) isUTF8_CHAR(buf, buf_end) |