Without being able to call pure functions within pure functions, what use is this beyond the trivial simple examples? Couldn&#x27;t it be possible to pass a &quot;this&quot; argument as the current JSON node and have it traverse the tree or something? For example:<p><pre><code>  {
    &quot;math&quot;: {
      &quot;sin&quot;: function(x) {...}
    },
    &quot;numerics&quot;: {
      &quot;sin2&quot;: function(x) {
        return this.parent.math.sin(x)
      },
      &quot;parent&quot;: [automatically inserted by parser]
    }
  }</code></pre>