Depth of nested list

[John Keith]

A couple of vague ideas here:

Convert to string, initialize a counter, loop through the string and increment the counter when a left brace is encountered, and decrement when a right brace is encountered. The maximum value is the depth of nesting. Would be slow for large lists.

Unpack the list, check the type of each item, if a list is encountered, unpack it and so on, keeping track of max. depth. Probably faster since one rarely encounters lists with nesting more than three levels deep.