From: David Alan Black <dblack@...>
Date: 2000-12-15T05:32:41+09:00
Subject: [ruby-talk:7251] Re: Why isn't Perl highly orthogonal?

Hello --

On Fri, 15 Dec 2000, Ben Tilly wrote:

              (map & grep)
> In Ruby the two concepts are orthogonal.  I don't yet know
> if you can have a function that returns different numbers
> of elements different times.  Certainly the first thing I
> tried to do with map was return 2 elements for 1.  (Looking
> at a case where I know current production versions of Perl
> doesn't scale.)  I couldn't see how to do it.  And grep
> itself cannot be used with arbitrary blocks.  (Therefore
> it is truer to the actual name of the function!)

(I remember being relieved when I discovered find_all, after trying
to get grep to act like Perl's grep.)

As for map mapping two(or more)-for-one, I've done it, when needed,
along these lines:

[1,2,3,4,5].map do |e| [e,-e] end .flatten 
  => [1, -1, 2, -2, 3, -3, 4, -4, 5, -5]


David

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