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- To: GJC at MIT-MC
- From: Robert W. Kerns <RWK at MIT-MC>
- Date: Mon, 20 Jul 81 20:15:00 GMT
- Cc: BUG-LISP at MIT-MC
- In-reply-to: The message of 20 Jul 81 14:06-EDT from George J. Carrette <GJC at MIT-MC>
- Original-date: Monday, 20 July 1981, 16:15-EDT
George, let me help you out. Don't scream about there being too many
optimizations. The problem here is the lack of one. Don't scream about
correctness... I think that's why = and EQ were being used, the reasoning
being along the lines of simple translation with an exception for them
nasty fixnums. Remember when you were flaming about defining a new
predicate to do this kind of comparison? I could be wrong, but I think
this was probably what JONL was thinking...it certainly was when I saw
what he did.
So anyway, I now perceive that you are (currently at least) perceiving
the situation correctly. I apologize for all my flaming back at you.
I admit I didn't get much sleep last night and am probably overreacting
to the flaming tone and content of your notes with flaming of my own.
Rather than try to show you on a point by point basis why I was mislead
by your notes, let me just show you how easily you could have said what
I now think you meant.
What you really wanted to tell us:
1) You have a bug (unquoted symbol). Please check before installing.
2) You can optimize out the (AND (NOT <fixnump>) ...) check
3) You can optimize for codesize (typically a 30% savings, for my guess
of "typical" code) at mere order-of-magnitude cost in speed, and GJC
believes it's worth it in MacLisp. Use EQ on clauses with single symbols,
otherwise use MEMBER or EQUAL.