>>45,48
JSON is good precisely BECAUSE it doesn't have a metric shit ton of useless types. Look at how short and simple a JSON parser is to write:
http://planet.plt-scheme.org/package-source/dherman/json.plt/1/1/json.ss
If you really want your data to be 'fully parsed', you can just wrap your json parser with a thin layer that converts your user defined types based on a table of keys and types. In other words you just tell it 'expiry_date' and 'creation_date' are both dates, and have it convert them for you. You can write this in ten lines of scheme.
One thing I absolutely do not want to do is litter my code with json_date_to_real_date(account.expiry_date)
Really? You can't do that conversion in the one place where you read the date, in the actual place it belongs? Instead you want to write a gigantic extensible XML parser than you can program your types into? Ah, you must be the J2EE programmer that makes my day job a living hell.