Robert Klemme
1/2/2007 5:02:00 PM
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