Function decodeModifier

src/ink/parse-keypress.ts:465–478

* Decode XTerm-style modifier value to individual flags. * Modifier encoding: 1 + (shift ? 1 : 0) + (alt ? 2 : 0) + (ctrl ? 4 : 0) + (super ? 8 : 0) * * Note: `meta` here means Alt/Option (bit 2). `super` is a distinct * modifier (bit 8, i.e. Cmd on macOS / Win key). Most legacy terminal * sequ

(modifier: number)

 * protocol (CSI u) or xterm modifyOtherKeys.
 */
function decodeModifier(modifier: number): {
  shift: boolean
  meta: boolean
  ctrl: boolean
  super: boolean
} {
  const m = modifier - 1
  return {
    shift: !!(m & 1),
    meta: !!(m & 2),
    ctrl: !!(m & 4),
    super: !!(m & 8),
  }
}

/**
 * Map keycode to key name for modifyOtherKeys/CSI u sequences.