🚀 go-pugleaf

In my experience this problem will only become manifest when
you compile this stuff into a file and load the file, not
c-sh-c in Zmacs.  Whenever you have quoted constants in
your source code these are loaded into read-only memory
when you compile file.  I have also seen this behavior
with defstructs, though not this particular instance.  I'm
not at my Exp right now so I can't check it.  When it has
happened to me I've always been able to copy the data structures
out of read-only memory fairly simply.

Note: you cannot do what I thought you should be able to
do in this case, i.e. backquote your constants and not
quote them.  For example, you cannot say:

(defvar *my-mutable-thing* `(a b c))

because CLtL (and the TI implementation) states that
backquote can be optimized into quote for constant
structures and that quoted structures are intrinsically
read-only.  This is really a bug in CL, which really needs
a simple syntax for denoting a mutable literal.



Rice.