Function isModifierKey

static/js/codemirror/codemirror.js:3241–3244

(event)

    }
  }
  function isModifierKey(event) {
    var name = keyNames[event.keyCode];
    return name == "Ctrl" || name == "Alt" || name == "Shift" || name == "Mod";
  }
  function keyName(event, noShift) {
    var name = keyNames[event.keyCode];
    if (name == null || event.altGraphKey) return false;