[READ-ONLY] Mirror of https://github.com/bombshell-dev/tty. Platform independent 2D layout engine for terminal applications based on Clay
📝 spec(renderer): specify caret behavior on empty text content
Adds a normative paragraph to §7.6 stating that a `caret` declaration on
empty content places the cursor at the text element's origin — the cell
where the first code point of `content` would be drawn if it were a
single space. Frames the empty-content case as a rendering commitment
the renderer must honor, without prescribing mechanism.
Charles Lowell
(Jul 8, 2026, 2:16 PM +0300)
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specs/renderer-spec.md
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specs/renderer-spec.md
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- If `N > [...content].length` or `N < 0`, behavior is unspecified; callers must
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keep offsets within bounds.
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When `content` is empty, the only in-range offset is `0`. In that case the
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caret's cell is the text element's origin — the cell at which the first code
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point of `content` would be drawn if `content` were a single space. This is a
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rendering commitment implied by the presence of a `caret` declaration, and the
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renderer must synthesize whatever minimal geometry is required to honor it. How
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this outcome is achieved is implementation-defined.
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Display position accounts for code points wider than one cell (CJK, fullwidth
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forms, some emoji): such code points occupy two cells, and the caret sits at the
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first cell of the pair. Cell widths are determined by the same measurement the