UNICODE_GRAPHEME_BRE(3)

NAME
unicode_grapheme_break, unicode_grapheme_break_init, unicode_grapheme_break_next, unicode_grapheme_break_deinit - unicode grapheme cluster boundary rules

SYNOPSIS

#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);

DESCRIPTION

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releases all resources used by the grapheme breaking handle, and the unicode_grapheme_break_info_t handle is no longer valid after this call.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().

SEE ALSO

TR-29[1], courier-unicode(7), unicode_convert_tocase(3), unicode_line_break(3), unicode_word_break(3).

AUTHOR

Sam Varshavchik
    Author

NOTES

1.  TR-29
    https://www.unicode.org/reports/tr29/tr29-43.html