> Lua combines arrays and dicts into "tables", which are usually indexed from 1 but can be indexed by any type as a dict.

I think it's more accurate to just call them hash tables ("dicts") that happen to support some very limited array-like functionality. "Appending" still looks like key insertion if you don't use a named method (https://stackoverflow.com/questions/27434142); `ipairs` misses those non-integer keys but also misses non-contiguous keys, or even a zero key (https://stackoverflow.com/questions/55108794); the `#` operator is not well defined once you add those non-contiguous keys (https://stackoverflow.com/questions/2705793) (so you can't actually cleanly override the choice to "start from 1"); slicing etc. aren't provided as operators (https://stackoverflow.com/questions/24821045); etc.