From: 7stud -- <bbxx789_05ss@...>
Date: 2009-08-27T01:15:05+09:00
Subject: Re: ||= with 1.8 and 1.9 ?

Brian Candler wrote:
> Aldric Giacomoni wrote:
>> It works as indicated. Is this -normal- behavior ?
> 
> FWIW, I get identical results to you using
> 
> ruby 1.8.6 (2007-09-24 patchlevel 111) [i486-linux]
> ruby 1.9.2dev (2009-07-18 trunk 24186) [i686-linux]
> 

$ r -v
ruby 1.8.6 (2007-03-13 patchlevel 0) [i686-darwin8.11.1]
$ r9 -v
ruby 1.9.1p243 (2009-07-16 revision 24175) [i386-darwin8.11.1]

$ r r1test.rb
"test"
"test"

$ r9 r1test.rb
"test"
"not test"


> In ruby 1.8, an attribute writer method (:foo=) always(*) returns the 
> value of its argument, rather than the last value calculated in the 
> method, so that you can tell by inspection that
> 
>    a = foo.bar = 123
> 
> will set a to 123. Perhaps it has been decided to change that for 1.9.
> 

If so, then David Black didn't know about it:

-------
WARNING   Setter methods don't return what you might think.  When you 
use the syntactic sugar that lets you make calls to = methods look like 
assignments, Ruby takes the assignment semantics seriously.  Assignments 
(like x = 1) evaluate to whatever's on their right-hand side.  [On the 
other hand,] [m]ethods usually return the value of the last expression 
evaluated during execution.  But = method calls behave like assignments: 
the value of the expression ticket.price = 63.00 is 63.00, even if the 
ticket= method returns the string "Ha ha!"  The idea is to keep the 
semantics consistent.  Under the hood, it's a method call; but it looks 
like an assignment and behaves like an assignment with respect to its 
value as an expression.
------
p. 72, The Well Grounded Rubyist


------
A word on Ruby versions

The Well Grounded Rubyist is about version 1.9.1 of the Ruby language, 
the most recent version.
------
p xxvii, The Well Grounded Rubyist




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