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a few questions
- Subject: a few questions
- From: kab (Kim Barrett)
- Date: Sat, 15 May 93 14:50:40
> 3. It appears that MCL interprets the symbol "-f1" as a floating point
> number. For instance, the expression:
> (let ((-f1 10)) -f1)
> results in the error:
> > Error: While compiling an anonymous function :
> > -0.0 is not a symbol.
> Is this a bug in MCL?
While the token "-f1" does not match the syntax of any actual kind of number
defined by Common Lisp, it is still a potential number (or "potnum"). See table
22-2 and the description of potential numbers, both on p.517 of CLtL2. Page 516
says "Any token that is a potential number but does not fit the actual number
syntax defined below is a \it{reserved token} and has an
implementation-dependent interpretation; an implementation may signal an error,
quietly treat the token as a symbol, or take some other action." Apparently,
MCL is "taking some other action" and interpreting it as -0.0.