Function C

resources/vega-lite.min.js:133–136

(e)

    return !0 === e || !1 === e;
  }
  function C(e) {
    const t = e.replace(/\W/g, "_");
    return (e.match(/^\d+/) ? "_" : "") + t;
  }
  function _(e, t) {
    return o(e)
      ? `!(${_(e.not, t)})`