Hofstadter on Lisp (1983)

(gist.github.com)

372 points Eric_WVGG | 3 comments | 16 Oct 24 13:44 UTC | HN request time: 0.476s | source

Show context

susam ◴[16 Oct 24 19:39 UTC] No.41862994[source]▶

In case anyone else is confused by what the functions named "oval" and "snot" mean in the following example:

  > (cond ((eq (oval pi) pie) (oval (snot pie pi)))
  (t (eval (snoc (rac pi) pi))))

I realised after a few seconds that they are meant to be "eval" and "snoc" instead. The above code should be written as the following instead:

  (cond ((eq (eval pi) pie)
         (eval (snoc pie pi)))
        (t (eval (snoc (rac pi) pi))))

This article has been a fascinating read, by the way. Kudos to the maintainer of the Gist post. I am also sharing these corrections as comments on the Gist post.

EDIT #1: Downloaded a copy of the original Scientific American article from https://www.jstor.org/stable/24968822 and confirmed that indeed the functions "oval" and "snot" are misspellings of "eval" and "snoc".

EDIT #2: Fixed typo in this comment highlighted by @fuzztester below.

replies(2): >>41863410 #>>41863652 #

1. fuzztester ◴[16 Oct 24 20:42 UTC] No.41863652[source]▶

>>41862994 #

>confirmed that indeed the functions "oval" and "snot" are misspellings of "eval" and "snot".

Correction of your correction:

confirmed that indeed the functions "oval" and "snot" are misspellings of "eval" and "snoc".

And I guess snoc is cons reversed and rac is car reversed.

replies(2): >>41864153 #>>41874145 #

2. susam ◴[16 Oct 24 21:44 UTC] No.41864153[source]▶

>>41863652 (TP) #

> Correction of your correction