From: Michael Brooks <michael.brooks@...>
Date: 2008-02-18T07:29:57+09:00
Subject: Re: Use of ? in variable names

Michael Brooks wrote:
> Hello everyone:
> 
> Why can't I name boolean variables with a "?" on the end?  The "?" can 
> be used on the end of methods but not variable.  
 >

Thank you everyone for your replies.

I realize that booleans aren't really a type in Ruby and I don't have a 
problem with that.  It's actually very cool that Ruby is designed to 
work that way.  Especially considering that variable being used as a 
boolean in Ruby can also me set to nil to indicate "answer unknown" like 
booleans in databases.

I'm not intending the "?" to control the parser or anything. It's just 
"decoration" to remind me that the variable or method is intended to be 
treated like a boolean when I'm looking at my code.  The "?" suffix is 
simpler than a "is_", "has_" prefix or "_flag" suffix for labeling 
booleans.  I believe one or two Ruby book even recommend that methods 
which act like booleans should end with names that have a "?".

So, its unfortunate that I can't put a "?" on the end of variables that 
do the same thing.  I realize I can wrap a variable in a method but 
that's a lot more code just to have boolean variables named the way I 
want.  And coding that way gets even uglier when I'm only using the 
variable privately within a method in which case putting wrappers around 
it would look weird.

Oh well... I guess the answer is just "you can't do it" and I'll have to 
leave it at that.

Thanks again for your replies.

Michael