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Re: Special Form Question
- To: masinter.pa@Xerox.ARPA
- Subject: Re: Special Form Question
- From: mips!escargot.earl@glacier (Earl Killian)
- Date: Mon, 16 Dec 85 16:29:10 pst
- Cc: common-lisp@SU-AI.ARPA
- In-reply-to: glacier!masinter.pa@Xerox.ARPA's message of 16 Dec 85 13:03 PST
Date: 16 Dec 85 13:03 PST
It would be more consistent and portable to define
(symbol-function 'quote) => nil.
under the theory that "symbol-function" really means to return a
function rather than "what this symbol means when seen as car of
something to be EVAL'd."
Similarly, it would be more consistent and portable to require that
after (defmacro foo --) that (symbol-function 'foo) also return nil.
This would mean that values returned by symbol-function could be assumed
to be functions, in the "funcall-able" sense.
It is likely that implementations will want to have some internal
"really give me what this symbol means when you see it as the CAR of a
form about to be EVALd" for use by the interpreter, but its not clear to
me why that primitive has to be "symbol-function".
Alternatively, you could leave symbol-function as the thing that
accesses a symbol's "function cell", and provide a new function that
is the same as FUNCTION, except that its argument is evaluated. It
could be applied to things other than symbols (e.g. lists with CAR =
LAMBDA). Call it FEVAL?? Then you could eliminate lambda
expressions as functions (the only argument for them was that you
needed to be able to construct functions on the fly -- now you can
construct lambda expressions and use FEVAL to turn them into