From: Robert Klemme <shortcutter@...>
Date: 2007-01-03T02:05:06+09:00
Subject: Re: operator precedence of assignment

On 02.01.2007 17:56, Yukihiro Matsumoto wrote:
> Hi,
> 
> In message "Re: operator precedence of assignment"
>     on Tue, 2 Jan 2007 22:26:53 +0900, Daniel DeLorme <dan-ml@dan42.com> writes:
> |
> |How do you think ruby parses this expression?
> |   a = 1 + b = 2 + c = 4 + d = 8
> |
> |Originally I thought that operator precedence would result in
> |   a = (1 + b) = (2 + c) = (4 + d) = 8
> |and since an assignment requires a variable, that would result in a SyntaxError. 
> |But instead it seems that everything on the right side of the assignment 
> |operator is evaluated first:
> |   a = (1 + (b = (2 + (c = (4 + (d = 8))))))
> |
> |That had me really puzzled at first but I guess the behavior makes a certain 
> |sense, and it's more useful than a syntax error. Ruby's tolerant parser wins again!
> 
> Ah, for your information, that surprised me as well.  Perhaps bison
> generated parser is smarter and eagerer than I expected.  I have no
> idea what to do.

I think Daniel did not want you to do anything - in fact he seems rather 
positively amazed. :-)

(The only thing that comes to mind is thank him for the praise. :-))

Kind regards

	robert