Steps through the input buffer 1 unicode character (glyph) at a time (ie, not necessarily 1 byte at a time). Bitwise 'and' our charset->mask with the mask for each glyph. This has the effect of limiting what charsets our charset->mask can match.
input text buffer (must be in UTF-8)
Steps through the input buffer 1 unicode character (glyph) at a time (ie, not necessarily 1 byte at a time). Bitwise 'and' our charset->mask with the mask for each glyph. This has the effect of limiting what charsets our charset->mask can match.