From: E S <eero.saynatkari@...>
Date: 2005-01-29T10:42:33+09:00
Subject: Re: Convert a Hash into an Array

> L�hett�j�: gabriele renzi <rff_rff@remove-yahoo.it>
> Aihe: Re: Convert a Hash into an Array
> 
> linus sellberg ha scritto:
> > georgesawyer wrote:
> > 
> >>> did I mention that I love #inject? :-)
> >>
> >> (Wistfully) Even though 'inject' is the name in Smalltalk, I feel it were
> >> better named, 'consolidate'.
> > 
> > 
> > I don't have anything against #inject, but I could see the case for an 
> > alias #accumulate, much like SICP's accumulate which afaik is the same 
> > thing.
> > 
> > (I wouldn't mind #reduce as well, though that would be slightly incorrect)
> 
> #fold would be better imho (even if slightly incorrect)

Well, since #foldr and #foldl are not offered, it may be better to 
call it #accum. On the other hand...

# ...if memory serves...
module Enumerable
  def foldl(accum, sym)
    self.each do |item| accum = accum.send(sym, item) end
  end
  def foldr(accum, sym)
    self.reverse.each do |item| accum = item.send(sym, accum) end
  end
end

>> [1,2,3,4,5].foldl 0, :-
=> -15          # (((((0 - 1) - 2) - 3) - 4) - 5)
>> [1,2,3,4,5].foldr 0, :-
=> 3            # (1 - (2 - (3 - (4 - (5 - 0)))))
>> [true, true, false, true].foldl true, :&
=> false        # ((((true & true) & true) & false) & true)

E