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@kentpitman@climatejustice.social
Post #1819353
2026-04-30 09:43 UTC
I couldn't find a copy of the memo named "Loop Iteration Macro" by Glenn Burke and David Moon, January 1981 (MIT/LCS/TM-169) at MIT's dSpace site, or anywhere else. So I scanned in my copy and have uploaded it to my web site.
NOTE WELL: This document was written prior to CLTL and describes a facility that was available in MACLISP and the Lisp Machine's Zetalisp. Common Lisp drew design ideas from this, but the syntax, semantics, and associated functions/macros described in this are NOT the same as what Common Lisp offers.
For example, my recollection from long ago (which I did not re-check before making this post) is that there are other differences in syntax because this earlier version of Loop was underconstrained in the ordering of the keywords in a way that let you write some expressions that the committee felt might confuse people with their results.
But also, for reasons that slip my mind, Common Lisp did not adopt the define-loop-path macro that is described starting on page 19.
http://nhplace.com/kent/History/maclisp/MIT-LCS-TM-169-Loop-Iteration-Macro.pdf
#lisp #maclisp #loop #iteration #ComputerHistory #KentsHistoryProject #lisp #LispM #Zetalisp #CommonLisp
cc @screwlisp
Replies (1)
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A primary source is a beautiful thing.
*
In my not so humble opinion, the finest uses of the Loop facility are those without `do' clauses.
Once I realized those are best viewed as if expressed in declarative style, I was no longer bothered by the "lack of parentheses".
Note that three years later Common Lisp specified `loop' while reserving forms with atoms in them, so it did specify enough for a REPL "in four".
(In REverse PoLish, of course;
WHOIS says that re.pl was created on 2000-03-14.)
#Alchemy
#CommonLisp
#DeclarativeProgramming
#DeclarativeProgrammingStyle
#Lisp
#Loop
#LoopFacility
@kentpitman@climatejustice.social @screwlisp@gamerplus.org
Open ##2369169