I want to write some data structures pointed to by FOO and BAR to a file, and to read the data structures back into the symbols FOO and BAR when I start a new session of Common Lisp.
It would appear *PRINT-READABLY* allows objects to be printed in a fashion that can be read back in by READ, and I can change how objects are printed using (defmethod print-object ...). Since the objects should be printed in a way acceptable to READ, I shouldn't have to define any further methods for reading the object back in.
But is there a way to tie each written data structure to its corresponding symbol, without having to rely on the order the data structures are written and read in?
If I understand correctly, you could store the values and associated symbols as pairs in the file, so something like this:
(x . (1 2 3 4))
(y . (6 7 8 1))
And when you parse it out, use something like this:
(let ((pair (read))
(set (car pair) (cdr pair)))