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- To: LISP
- Subject: VALUEOF
- From: TEITELMAN
- Date: Sun, 29 Oct 1978 22:12:07 -8000
- Date: 29 OCT 1978 2212-PST
the problem with valueof is how to decide whethe or
not the event that caused the call to valueof is to be considered
when handling negative event specifications. it used
to be the case that valueof siplemindedly always backed
up the history list one, i.e. always ignored the current
event. thus your show comand worked. hwever,
if the user typed to the editor (I : (VALUEOF-1)), this
was incorrectly handled, since in this case, the event
causing the call to VALUEOF was not on the history list.
e.g. if user typed E -- and then (I : (VALUEOF -1))
the last event on lispxhistry was the -- from the E.
i changed VALUEOF therefore to check and see whethe
VALUEOF itself appeared in the type in. obviously this
is too strong a check for your case
where the user types in an expression which causes
a call to valueof via the SHOW command. the best i can do
for you i think is to separate out VALUEOF into two functions
and let you call a lower function with the event spec and
a flag which indictes whether or not to backup.
i am open to other suggestions.