... I can't guarantee the availability of any non-core modules on whatever system this ends up running on.

It's also useful to know if some minimal Perl version can be expected or not. Ferinstance, version 5.10 adds a bunch of really neat regex extensions, e.g., the recursive  (?PARNO) pattern family.

It's also good to know if the format of the data is as strict as is suggested by your OPed example data; tybalt89's solution depends on the opening keyword and terminal delimiter of each
    object "identifier" in { ... };
group both desperately hugging the left margin, and any departure from this will sink you.