From: Marnen Laibow-Koser <marnen@...>
Date: 2009-11-25T02:19:35+09:00
Subject: Re: Difference between << and += for Strings and Arrays. Bug

Pieter Hugo wrote:
> Hi Guys
> 
> Thanks for the quick responses and insights. While I understand the 
> issue now I must confess that it perturbs my 'least surprise' 
> expectation.

According to Matz, POLS is only meant to apply within Ruby, not with 
respect to other languages.

> Why was it decided that '<<' should reference the original 
> object but '+' should create a new object. 

That's the way those two operators work in most classes where they're 
both defined.  It's not that surprising.

> When one works with a 
> variable one shouldn't need to worry about what other stuff is being 
> modified due to a unintentional reference?

Actually, keeping this straight is a fundamental part of programming in 
Ruby.  You can always use dup or clone to be safe.

> What other operators are 
> doing this?

Ask the code, not us.

Best,
--
Marnen Laibow-Koser
http://www.marnen.org
marnen@marnen.org
-- 
Posted via http://www.ruby-forum.com/.