From: Brian Marick <marick@...>
Date: 2008-08-25T02:02:42+09:00
Subject: Re: Why 'if 0' succeeds in Ruby


On Aug 23, 2008, at 8:35 PM, M. Edward (Ed) Borasky wrote:

> Exactly! To make matters worse, Lisp "traditionally" treated nil as
> false, but Scheme has "true", "false" and "nil" and nil is treated as
> true in Scheme.
>
> So I don't have a problem with 0 not being false, but I do have a
> problem with nil being false in Lisp and Ruby and true in Scheme. 0 is
> 0, nil is nil, true is true and false is false and that is that!


Back in my Common Lisp days, some Lisper (George Carrette, I think)  
wrote about a dream he'd had. In it, he'd just written a fairly simple  
piece of Lisp code when he realized Scheme's strictness was right. The  
rest of the post was of the form:

	... and then I realized that Scheme was right about X and my code
	had been taking advantage of Lisp's sloppiness. So I fixed that...

The punch line was that every "fix" made the code longer and more  
complicated. It was brilliantly done, and I'm sad I've never been able  
to find it.

One of the simplifications/complexifications was separating nil and  
false.

-----
Brian Marick, independent consultant
Mostly on agile methods with a testing slant
www.exampler.com, www.exampler.com/blog, www.twitter.com/marick

-----
Brian Marick, independent consultant
Mostly on agile methods with a testing slant
www.exampler.com, www.exampler.com/blog, www.twitter.com/marick