layer(): passing through modifier keys about karabiner.ts HOT 2 CLOSED

  layer('f', 'f-arrow-mode').manipulators([
    map('i', undefined, 'any').to('↑'),
    map('j', undefined, 'any').to('←'),
    map('l', undefined, 'any').to('→'),
    map('k', undefined, 'any').to('↓'),
  ]),

  layer('f', 'f-arrow-mode').manipulators([
    withMapper<FromKeyParam, ToKeyParam>({
      i: '↑',
      j: '←',
      l: '→',
      k: '↓',
    })((k, v) => map(k, undefined, 'any').to(v)),
  ]),

  rule('Letter to Modifiers').manipulators([
    map('d').to('left_shift').toIfAlone('d'),
    map('s').to('left_option').toIfAlone('s'),
  ]),