Function extractCompleteSequences

packages/pi-tui/src/stdin-buffer.ts:192–255

(buffer: string)

}

function extractCompleteSequences(buffer: string): { sequences: string[]; remainder: string } {
	const sequences: string[] = [];
	let pos = 0;

	while (pos < buffer.length) {
		const remaining = buffer.slice(pos);

		// Try to extract a sequence starting at this position
		if (remaining.startsWith(ESC)) {
			// Find the end of this escape sequence
			let seqEnd = 1;
			while (seqEnd <= remaining.length) {
				const candidate = remaining.slice(0, seqEnd);
				const status = isCompleteSequence(candidate);

				if (status === "complete") {
					// WezTerm with enable_kitty_keyboard sends the Escape key press as a
					// raw '\x1b' byte (simple text path in encode_kitty, ignoring
					// DISAMBIGUATE_ESCAPE_CODES) and the release as a full Kitty CSI-u
					// sequence. These arrive concatenated as '\x1b\x1b[27;...u'.
					// The buffer would normally treat '\x1b\x1b' as a complete meta-key
					// sequence (ESC + single char), leaving '[27;...u' to be typed as
					// plain text. If the character immediately following '\x1b\x1b'
					// would begin a new escape sequence, emit only the first ESC and
					// restart from the second.
					if (candidate === "\x1b\x1b") {
						const nextChar = remaining[seqEnd];
						if (
							nextChar === "[" || // CSI
							nextChar === "]" || // OSC
							nextChar === "O" || // SS3
							nextChar === "P" || // DCS
							nextChar === "_" // APC
						) {
							sequences.push(ESC);
							pos += 1;
							break;
						}
					}
					sequences.push(candidate);
					pos += seqEnd;
					break;
				} else if (status === "incomplete") {
					seqEnd++;
				} else {
					// Should not happen when starting with ESC
					sequences.push(candidate);
					pos += seqEnd;
					break;
				}
			}

			if (seqEnd > remaining.length) {
				return { sequences, remainder: remaining };
			}
		} else {
			// Not an escape sequence - take a single character
			sequences.push(remaining[0]!);