| name | ansi-escape-codes |
| description | Use when working on TaTUÍ's ANSI backend or event parser: SGR styling, cursor movement, raw mode, alt screen, mouse capture, or decoding input escape sequences. Triggers: ANSI, escape sequence, SGR, CSI, termios, raw mode, alt screen, cursor move, color degradation, mouse, bracketed paste. |
ANSI escape codes
Only src/tatui/backend/ and the event reader emit/decode escape sequences.
Output (backend)
- Style via SGR (
CSI ... m). Reset with CSI 0 m only when needed; track current style to avoid
redundant sequences.
- Move the cursor with absolute positioning (
CSI row ; col H) only when the next changed cell is
not adjacent; otherwise let natural advance handle it. Minimize total bytes.
- Color degradation: truecolor (
38;2;r;g;b) → 256 (38;5;n) → 16, chosen by backend capability
(ADR-0012).
- Lifecycle: enter raw mode (termios) + alt screen (
CSI ? 1049 h) + optional mouse capture on init;
restore all on teardown via defer/destructor, even on panic (ADR-0008).
Input (event reader)
- Decode CSI/SS3 sequences into key/mouse/resize/paste events (ADR-0007).
- The parser must be total: malformed or partial sequences yield a best-effort event or are buffered,
never crash. Fuzzed by
tests/fuzz/ansi_parser_smoke.nim.
References
Trimmed ECMA-48 SGR table and xterm ctlseqs subset live in docs/reference/terminal/.
