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Comment by cronjobber | Hacker News Reader

Hacker News is implemented in a dialect of Lisp designed by a guy who wrote multiple books on Lisp. Seems even lispers don't learn:

> The assignment operator is =. I was dubious about this, but decided to try it and see if I got used to it. It turns out to work well, even in prefix. Stripes stand out, which is why they get used on warning signs and poisonous animals.

http://www.paulgraham.com/arcll1.html

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That is quite silly. I briefly contemplated this idea for TXR Lisp, but completely rejected it. The = function is numeric comparison, like in Common Lisp. You don't want to turn that into assignment. People used to Lisp dialects where = is numeric comparison will make the mistake:

  (if (= whatever whatever-else) (you-got-burned))

Arc code written by people used to Lisp dialects where = is a pure comparison function, or Arc code converted from other Lisp dialects, has to be carefully reviewed against this.

If I put this into a Lisp dialect, I would make the code walker issue a warning whenever the value of a (= ...) assignment is used, and provide an alternative assignment operator which doesn't have that warning.

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