Function parseOscColor

src/ink/termio/osc.ts:317–342

(spec: string)

 * to 8-bit). Returns null on parse failure.
 */
export function parseOscColor(spec: string): Color | null {
  const hex = spec.match(/^#([0-9a-f]{2})([0-9a-f]{2})([0-9a-f]{2})$/i)
  if (hex) {
    return {
      type: 'rgb',
      r: parseInt(hex[1]!, 16),
      g: parseInt(hex[2]!, 16),
      b: parseInt(hex[3]!, 16),
    }
  }
  const rgb = spec.match(
    /^rgb:([0-9a-f]{1,4})\/([0-9a-f]{1,4})\/([0-9a-f]{1,4})$/i,
  )
  if (rgb) {
    // XParseColor: N hex digits → value / (16^N - 1), scale to 0-255
    const scale = (s: string) =>
      Math.round((parseInt(s, 16) / (16 ** s.length - 1)) * 255)
    return {
      type: 'rgb',
      r: scale(rgb[1]!),
      g: scale(rgb[2]!),
      b: scale(rgb[3]!),
    }
  }
  return null
}

/**
 * Parse OSC 21337 payload: `key=value;key=value;...` with `\;` and `\\`