On Sat, Jun 6, 2020 at 12:41 PM João Távora wrote: > On Sat, Jun 6, 2020 at 2:43 AM Paul Eggert wrote: > >> On 6/5/20 4:19 PM, João Távora wrote: >> > I totally agree it is >> > undefined behaviour to change structure of literals (quoted or >> > self-evaluating objects), also in Common Lisp, because compilers are >> > probably allowed to reuse parts of the internal structure of such >> > objects. But that's a far cry from having two different manifestations >> > of `equal` such objects _be_ the same object, but only for compiled >> > code. >> >> I don't understand this remark, as the idea that "compilers are allowed >> to reuse >> parts" necessarily implies that (eq "a" "a") can be t if the compiler >> decides to >> reuse the string. > > > Depending on the implementation of sequences, it could reuse only the > later parts of the sequences to maintain uniqueness and still have > I forgot to finish the sentence: "and still have some some reuse". João