Lightning Review: LISP 1.5 Programmer’s Manual
The LISP 1.5 Programmer’s manual, published first in 1962 and reprinted with essentially no change through at least 1985, is a pocket-sized volume that runs to just over a hundred pages and which contains almost enough information to recreate the language — and the computer that ran it!
It should settle a lot of arguments. That lisp is complicated, that lisp is bloated, that garbage collection is too slow, and that there are too many parentheses. This last one is the biggest surprise to me. A substantial portion of the book expresses lisp programs in M-expressions, the ‘meta-expressions’ that the authors expected would be actually used to write lisp programs. These can be converted to S-expressions as a pedagogical exercise, of course, but they did not expect users to actually write directly in S-expression. It won’t settle any of these arguments, of course, but it should.
Everything that subsequent generations of students found revelatory about lisp is typeset with nonchalance, which is like sans serif, but excitement is stripped away instead of the curlicues on the ends of letters. (In cryptography, a nonch is basically a nonce that you would just note casually in the spec without making a whole thing out of it.)
In fact, the manual made recursive, functional programming downright approachable. Here is a runtime you might like to sit down and split a pizza and a pitcher of beer with. Nowhere was this more true than in the error listings for Overlord, the system monitor. “Bad input but going on anyhow” is the kind of response you might expect from a friend and rarely from a machine monitor. Maybe LISP had a more advanced artificial intelligence that we recognized at the time.
”LISP 1.5 …” was released first in 1962 and remained relevant for decades after - keypunches, tape drives, and all. It’s easy to forget that the Artificial Intelligence group at MIT that contributed had pressed on to artificial intelligences years before the US had affirmed the natural humanity embodied in Loving v. Virginia. Not like today, when … Never mind, in retrospect the rise of ChatGPT is a completely predictable, recursive response to the state of the world. Whether because it’s more escapist than a binge of West Wing or more algorithmically dehumanizing than race taxonomy on the US Census, AI is something that can appeal to all the angels of our nature.
Anyhow, ”Lisp 1.5” is a fine appeal to the angels of our artifice. Available free online or used for little more than the original retail price. Our Paper Tiger score is 4 paws.
”LISP 1.5 Programmer’s Manual” / 1962 / MIT Press / ISBN 0 262 13011 4