From: David Alan Black <dblack@...>
Date: 2000-12-13T05:36:02+09:00
Subject: [ruby-talk:7108] "map_with_indices" and related musings

Hello --

So many recent discussions here of Array (and/or Enumerable) methods seem to
involve arrays knowing how to do things with other arrays, generally in exact
alternation: interleaving, hashing themselves against their own indices,
getting iterated over at the same time....

Well, here's another.  I reproduce it here because I've found it useful, am
curious whether other people have invented something similar, and wonder
whether there's a more streamlined way to do it.  Also...  well, here it is,
first:

  class Array

    def map_with_indices
      res = []
      each_with_index do |e,i|
	res.push yield e,i
      end
      res
    end

  end

...to continue, re: Array enhancements:  I wonder whether there's some
unifying, underlying Thing that all these problems we're solving are mutually
doing.  If so, what exactly is that Thing (interleaving with self's indices?) and
can the cluster of methods we've been talking about (interleaving, to_hashing,
etc.) be factored and constructed, as a group, to reflect that unity?


David

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