RE: can s-exprs represent a graph without eval?

["Anton van Straaten" <address@hidden>]

Guy Steele wrote:
> Sometimes an circular structure can be used to "advantage".
> Consider this bit of code:
>
>   (mapcar #'+ x '#1=(1 -1 . #1#))    [corrected]
>
> If x is (1 4 7 10), the result will be (2 3 8 9).
>
> Does this puzzle you?  You get 1 point.
> Does this delight you?  You get 5 points.
> Does this nauseate you?  You get 10 points.

I can see nauseating aspects, but related more to cryptic syntax than
anything else.  Should the following Haskell also be considered nauseating,
and if so, why?

  x = [1, 4, 7, 10]
  altlist = 1 : -1 : altlist
  zipWith (+) x altlist
=>
  [2,3,8,9]

Not sure if the infinite list can be defined inline, but if not, it's
probably a good thing which reduces the nausea factor.

My delight with this version is only moderated by the typing rules, which
require that a different function be used with a different number of input
lists (map vs. zipWith).

Anton