From: Gary Wright <gwtmp01@...>
Date: 2011-01-25T05:26:33+09:00
Subject: Re: The finer points of postfix conditionals.


On Jan 24, 2011, at 1:18 PM, Jon Leighton wrote:

> Thanks for the explanation. FWIW I think it is a shame that postfix 
> conditionals are semantically different to normal ones, but it's good to 
> know why the difference occurs.

I think you are reversing cause and effect. The postfix condition
is not the source of the semantic surprise.

The surprise comes from the way Ruby disambiguates local variables
from argument-less method calls *at parse time*.  You can contrive
other examples of this surprise:

x rescue puts("x isn't a method here")
x = true
puts "x is now a local variable" if x
x rescue puts("this won't fail now because parser thinks x is a local variable")
x() rescue puts ("x still isn't a method")

Gary Wright