Convert a Hash into an Array

ruby-talk
1

Lähettäjä: 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? :slight_smile:
>>
>> (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