| name | unicode-width |
| description | Use when handling text, graphemes, or cell width in TaTUÍ: Span/Line/Text, wide (CJK/emoji) characters, the cell skip flag, or grapheme segmentation. Triggers: unicode, grapheme, wide char, CJK, emoji, width, skip flag, combining, ZWJ. |
Unicode width & graphemes
Correct cell width is a hard correctness requirement: a wrong width corrupts the diff for the whole
frame.
Rules
- A cell holds one grapheme cluster, not one code point (combining marks, ZWJ emoji sequences).
- Display width per grapheme is 0, 1, or 2 columns.
- A width-2 grapheme occupies two cells: the first holds the symbol, the second is marked
skip=true
and is not independently written or diffed.
- Zero-width graphemes (combining marks) attach to the preceding cell.
When writing to a buffer
- Advance the cursor by the grapheme's display width.
- Clear the trailing
skip cell so stale glyph halves cannot leak through the diff.
- Truncation must never split a wide grapheme; pad with a space if only one column remains.
References
docs/reference/terminal/ for width tables; ADR-0006 for the chosen segmentation approach.
