A comment or two: Your code actually only encodes/decodes lists and dictionaries, it will completely ignore single values, eg it wont parse "4:spam" at all. You also have the string/integer parsing code in there twice. You can solve both of these in one go by making the main if (substr(${$dictref},0,1) eq "d") { statement also do strings and integers, and recursing when encountering these inside the dictionary/hash, instead of parsing them on the spot.

Ditto the encoding.

Pretty nifty all the same :)

C.