Utility used in order to avoid ugly nested ternary statements. (Idea: https://medium.com/fractions/3-more-marvelous-javascript-tips-to-skyrocket-your-productivity-ba75f72b0195)

is.js

const is = (val) => ({
  if: (expr) => {
    if (expr)
      return {
        else: () => val,
        is: function is() {
          return {
            if: () => ({ else: () => val, is }),
          }
        },
      }
    else return { else: (e) => e, is }
  },
})