[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
OR and Multiple Values
- To: common-lisp@SAIL.STANFORD.EDU
- Subject: OR and Multiple Values
- From: MURRAY%cs.umass.edu@RELAY.CS.NET
- Date: Fri, 17 Apr 87 18:27 EDT
> Is it reasonable to expect SOME to return multiple values?
> What if the predicate returns multiple values?
>>No, for the same reason that OR returns only a single value for clauses
>>other than the last one. That is, the implicit NULL test "consumes" the
>>values returned from the predicate, discarding all but the last one.
I've always been a little disturbed by this fact. I suppose the
extra effort to always insure multiple values are dealt with "properly"
is probably not worth it in general. However, I'll take this opportuntiy
to again ask for a MULTIPLE-VALUE-OR special form, since it cannot be
defined without consing in Common-Lisp (I guess it COULD be a macro that
expands into consing code, but the compiler would know about, but that is