[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Purity and DISPLACE
- To: ALAN at MIT-MC
- Subject: Purity and DISPLACE
- From: RWK at MIT-MC (Robert W. Kerns)
- Date: Tue, 30 Dec 80 01:16:00 GMT
- Cc: (BUG LISP) at MIT-MC
- Original-date: 29 DEC 1980 2016-EST
In actual fact, I got disgusted enough to do something about it already.
MACROMEMO checks before clobbering, and does a hash-style memoizing instead
of a displace-style memoizing instead if the arg is pure. For this purpose
this is superior to DISPLACE doing the checking and punting, since the macro
doesn't get re-expanded. However, I agree that DISPLACE would be more
useful if it checked. KMP, as you recall, would disagree.