unicode-width

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.