Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!SUMEX-AIM.STANFORD.EDU!rice From: rice@SUMEX-AIM.STANFORD.EDU (James Rice) Newsgroups: comp.sys.ti.explorer Subject: re: defstruct copy Message-ID: Date: 20 Mar 90 19:46:17 GMT Sender: daemon@ucbvax.BERKELEY.EDU Distribution: inet Organization: The Internet Lines: 25 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.