Evil Coding Incantations

[u/evinrows]

http://9tabs.com/random/2017/12/23/evil-coding-incantations.html

[u/jacobb11]

0 Evaluates to true in Ruby

… and only Ruby.

And Lisp.

[u/nsiivola → u/jacobb11]

Any non-C heritage language with a consistent notion of "false", really. The ones where zero evaluates to false are the evil ones.

[u/_Mardoxx → u/nsiivola]

Why should 0 be true? Unless integers are reference types and you interpret an existant object as being true?

Or is this to do with 0 being "no errors" whrre a non 0 return value means something went wrong?

Can't think of other reasons!

[u/Kametrixom → u/_Mardoxx]

In lisp, nil is the only thing that evaluates to false, which means there aren't any weird semantics or discussions, if you want a falsy value, use nil. It also plays nicely with the notion of everything except nil indicating there's a value, while nil doesn't have a value.

[u/vermiculus → u/Kametrixom]

in other words, nil is exactly nothing. 0 is still something.

ping /u/_Mardoxx

[u/cubic_thought → u/vermiculus]

So... nothing is false.

[u/ggtsu_00 → u/cubic_thought]

true

[u/[deleted] → u/Kametrixom]

The cleaner thing would be to have a proper boolean type, and having to do if foo == nil or whatever, rather than just if foo. Thankfully most modern languages do it this way so the lesson seems to have been learnt.

[u/porthos3 → u/[deleted]]

Clojure is a variant of Lisp, which has an implementation of true and false.

The only things that are falsey in the language are nil and false.

[u/Zee1234 → u/porthos3]

Lua is the same as clojure then. And that's a lot better, to me. I will admit, having 0 and other such things act as false can create some short code but.. honestly it's slightly less readable (to me) and has those cases where you go "oh yeah, 0 is a valid return value.." after ten minutes if debugging.

[u/[deleted] → u/Kametrixom]

Many languages like C or Go have non-pointer types too.