From: Hal Fulton <hal9000@...>
Date: 2005-08-08T02:22:09+09:00
Subject: Re: cartesian product

Randy Kramer wrote:
> On Sunday 07 August 2005 10:51 am, Martin DeMello wrote:
> 
>>if block_given?
>>  yield ae, be
>>else
>>  (c ||= []) << ae, be
>>end
> 
> 
> I'm sure you know what you're talking about, but I wonder how many others 
> will, even with comments.  (Maybe I just need to go back to Pascal?)

Haha... if it's this line you have trouble with

   (c ||= []) << ae, be

it's not that hard.

The ||= is a well-known idiom -- same as c = c || []  here. Basically
"assign c this value, unless it is already non-nil."

So then you have either an existing array or an empty one.
Then you can append (<<) onto it.

If it's the yield that bothers you, just study a bit more
Ruby. Pascal was wonderful in 1980 -- unless you already knew
something better -- but I'm content to let it go now. ;)


Hal