John Carmack on Mutable Variables

Re:John Carmack on Mutable Variables by tmtvl on Friday October 31, 2025 @05:47AM (#45770119)

Lisp syntax is objectively superior because you can write a predicate like thus:

  (< lower-bound x-coordinate upper-bound)

Instead of having to do the awful ampersand dance.

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Re:John Carmack on Mutable Variables by kragen on Friday October 31, 2025 @11:37AM (#45773270)

In Python or Icon (or Unicon) that's

    lower_bound < x_coordinate < upper_bound

except that usually you want

    lower_bound <= x_coordinate < upper_bound

which is also legal.

In Python this is a magical special case, but in Icon/Unicon it falls out somewhat naturally from the language semantics; comparisons don't return Boolean values, but rather fail (returning no value) or succeed (returning a usually unused value which is chosen to be, IIRC, the right-hand operand).

And in SQL you have

    `x-coordinate` between `lower-bound` - 1 and `upper-bound` + 1

which is obviously the best possible syntax.

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