> For simplicity's sake I haven't > implemented a type declaration right now, just an is_list() function, > but it could easily be extended to one
This is a crucial question – should is_list function like is_numeric($some_string), where is_list just tells you about the keys in the array at a given point in the program, or should it function like is_int, where it tells you about the type. I lean towards the latter (which would make the implementation of is_list simpler, but would complicate everything else.
