Just published a shard to determine the graphemes cluster boundaries of unicode text.
In Crystal, String class provides a codepoints method to return Unicode code points. However, multiple code points may be combined into one user-perceived character or what the Unicode specification calls grapheme cluster.
This shard provides a tool to iterate over these grapheme clusters. This may be used to determine the number of user-perceived characters, to split strings in their intended places, or to extract individual characters which form a unit.