Re: EVAL-WHEN

[NGALL@G.BBN.COM]

    Date: Thu 3 Apr 86 22:52:12-EST
    From: "Rodney A. Brooks" <BROOKS%OZ.AI.MIT.EDU@XX.LCS.MIT.EDU>
    To: Bobrow.pa@XEROX.COM
    Subject: Re: EVAL-WHEN
    In-Reply-To: <860403-181205-2031@Xerox>
    Message-ID: <12196029728.56.BROOKS@OZ.AI.MIT.EDU>
    
	Doesn't 
	(setf (symbol-function 'foo) (COPY '(LAMBDA  ...)))
	guarantee to produce a function definition not compiled by compiling the
	file.  If (setf (symbol-function 'foo) ...) compiles, then all bets are
	off.
    
    There is no requirement in CLtL that it be legal for a symbol function
    cell to contain a lambda expression. In some implementations this
    will cause an error when such a symbol is used in the function
    position of an eval-ed expression. These implementations place a closure
    in symbol function cells for interpreted functions, which all point
    to the same compiled code sequence which takes a literal from the
    closure (the literal is the lambda expression) and does the right
    call into the middle of the interpreter. 
    -------
    
	      --------------------
		
This should definitely be pointed out on page 90.  Also, exactly what objects
may be the value in a setf of (symbol-function <<symbol>>) should be clarified.

	-- Nick