Embedded/nested patterns

[pointlessone]

Say, I have a file that embeds a bunch of other known formats. For example, a pack-like format that embeds a bunch of wavs. Let's assume it has a header that specifies sections of the file that contain individual wavs (e.g. offset and length).

• How do I import another pattern/hexpat file?
• How do I specify a container region so that the pattern could use std::mem::eof() and offsets relative to its region?