[no subject]

[Daniel L. Weinreb <dlw at MIT-AI>]

But if string-right-trim were defined to not necessarily copy, and you
used "copystring" to copy the result, then you would sometimes end up
copying the string twice, which is also undesirable.  In general, the
string functions that return new strings and don't have something about
being destructive in their names are not destructive.  I'd hate to make
the rule more complicated and start introducing bugs because people made
the natural assumption that string-right-trim always creates a new string.