DF-structures is the core information on which DFHack depends.
Originally dfhack used a file called
to describe data structures of the game. It explicitly
listed addresses of known global variables, and offsets
within structures to fields, not unlike the ini files
used by Dwarf Therapist.
However, as the number of known fields and objects grow, maintaining the explicit offset lists quickly becomes difficult, error prone, and inefficient.
This format instead represents data structure layout purely via listing all fields in the correct order, exactly like a structure definition does in the C++ language itself. There is still a file with numeric data, but it only contains absolute addresses of global objects.