From: David Alan Black <dblack@...>
Date: 2001-12-01T02:38:12+09:00
Subject: [ruby-talk:27095] Re: Using Enumerable

Hi --

On Sat, 1 Dec 2001, Matt Armstrong wrote:

> David Alan Black <dblack@candle.superlink.net> writes:
>
> > Or even:
> >
> >         def each
> >           yield *@pointer + 1 .. @end
> >         end
>
> What is going on with this code?  I can't figure it out.

Whoops, I guess I crossed the line :-)

Here's what's going on:

   @pointer + 1 .. @end

is a range.

If you yield a range:

   yield @pointer + 1 .. @end

the result is that you've only yielded one thing -- namely, a range.
So instead of yielding 1, then 2, then 3.... you'd just yield (0..10).

However, the asterisk breaks the range out into its elements.  Compare:

p 1..5

 # prints:  1..5

p *1..5

  # prints: 1
            2
            3
            4
            5


So... yield *(some range) is shorthand for yielding each element of
the range separately.


David

-- 
David Alan Black
home: dblack@candle.superlink.net
work: blackdav@shu.edu
Web:  http://pirate.shu.edu/~blackdav