WordPress trick: wp_parse_args() is a helpful function for taking configuration arrays passed to a function and combining them intelligently with the default arguments for the function. I needed a recursive version, for use with multi-dimensional arrays of arbitrary depth, so I wrote the little ditty below. As I note in the docs, there are fundamental ambiguities in the process of rectifying multi-d arrays, and the technique I’ve chosen is specific to my implementation. Use at your own risk.