unicode_grapheme_break, unicode_grapheme_break_init, unicode_grapheme_break_next, unicode_grapheme_break_deinit — unicode grapheme cluster boundary rules


#include <courier-unicode.h>
unicode_grapheme_break_info_t unicode_grapheme_break_init( void);  
int unicode_grapheme_next( unicode_grapheme_break_info_t handle,
  char32_t c);
void unicode_grapheme_deinit( unicode_grapheme_break_info_t handle);
int unicode_grapheme_break( char32_t a,
  char32_t b);


These functions implement the unicode grapheme cluster breaking algorithm. Invoke unicode_grapheme_break_init() to initialize the grapheme cluster breaking algorithm. unicode_grapheme_break_init() returns an opaque handle. Each subsequent call to unicode_grapheme_break_next() passes this handle, and the next character. unicode_grapheme_break_next() returns a non-0 value if there's a grapheme break before the character, in a sequence of Unicode characters. unicode_grapheme_break_deinit() releases all resources used by the grapheme breaking handle, and the unicode_grapheme_break_info_t handle is no longer valid after this call.

The first call to unicode_grapheme_break_next() always returns non-0, as per the GB1 rule.

unicode_grapheme_break() is a simplified interface that returns non-zero if there is a grapheme break between two unicode characters a and b. This is is equivalent to calling unicode_grapheme_break_init(), followed by two calls to unicode_grapheme_break_next(), and finally unicode_grapheme_break_deinit(), then returning the result of the second call to unicode_grapheme_break_next().