Proposal #13: Structure Sharing in Arguments

[John Diamant <hpfcjrd!diamant@hplabs.HP.COM>]

	Subject: #5, #5A, #6, #7, #8, #9, #9A, #9B, #10, #11, #12, #13, #14
	From: Kent M Pitman <hplabs!KMP@SCRC-STONY-BROOK.ARPA>
	
	Proposal #13: Structure Sharing in Arguments
	
	 In the case of &REST in macros, I see no reason to not simply say 
	 that the argument list is -always- shared. Is there an argument for 
	 why this might not always be possible? In the case of &BODY, it may 
	 not be possible to do the sharing, so I'm willing to leave this 
	 undefined and say it "is an error" to modify the list.
	
A language specification has no business specifying implementation details.
Requiring that the list be shared is an efficiency requirement, not a
language specification.  I agree with the warning that the list may be
shared, but I certainly wouldn't require it!

	John