From: Martin DeMello <martindemello@...>
Date: 2003-08-10T14:33:40+09:00
Subject: Re: Ruby and OOP-design (question of an old "procedural person" ;)

Hal E. Fulton <hal9000@hypermetrics.com> wrote:
> 
>> Well and good, but they don't document the fact that the return value
>> can be used as anything other than a boolean. Duck typing or no, I find
>> it conceptually messy to have a method called nonzero? return self
>> rather than true - compare nil? and zero?. Using the value of self feels
>> like relying on an undocumented side effect. 
> 
> But as long as it isn't false or nil, it *is* true in effect.
> And it's far from undocumented.

I just said it *felt* like using an undocumented side effect, since it
embraces-and-extends what I've been thinking of as the implicit contract
of a ? method.

> Yet in a way I sympathize... where I *would* feel funny is if
> I made use of the numeric value returned rather than just
> checking its truth... but I could probably get over even that.

And likewise it feels funny when I see it in someone else's code. It may
be useful, but so are a lot of other things that didn't make it into
ruby because the semantics conflicted with the name.

martin