From: Tom Sawyer <transami@...>
Date: 2002-08-27T15:19:49+09:00
Subject: Re: ANN: RJudy-0.1 - Judy Arrays for Ruby

Lyle,

i don't recall if you ever expressed an opinion on the concept of a
Mixed Hash + Array type class. just to give you the quick idea if you
didn't follow those old threads: (i'll use ( .. ) for the literal
bracket notation of this Array+Hash entity)

  mix = ( 'w', :b => 'x', 'y', :d => 'z' )

from this you can see we have two elements with a specified key and two
without. concievably we could just treat this as an array:

  puts mix[0]  # ==> w
  puts mix[1]  # ==> x

or we could access it as a hash:

  puts mix[:b]  # ==> x
  puts mix[:d]  # ==> z

i did some work on this myself, but i don't have the time right now to
pursue it. but in doing so, i discovered the crux of difficulty that
would need to be addressed: the ambiguity between an integer hash key
and an array index, but if this could be thought through and a solution
arrived at, i belive it would make for a more elegent and powerful type
of sequence class.

anyway, i bring this up simply becasue you're in the process of
implementing this great new hash class, so i thought you might want to
give it some consideration.

~transami

p.s. if i get some time soon, i'll give RJudy a whril. thanks for the
great work!



On Mon, 2002-08-26 at 23:41, Lyle Johnson wrote:
> All,
> 
> I've just uploaded RJudy, an extension module that provides a Ruby 
> interface to the Judy arrays library. This extension exposes four new 
> classes to Ruby (Judy1, JudyL, JudySL and JudyHash). The first three are 
> more-or-less direct wrappers of the current Judy API. The last is a 
> first cut at a more general replacement for Ruby's Hash (i.e. with 
> arbitrary-type keys), based on the approach described in the Judy 
> application note "Scalable Hashing".
> 
> The RDoc documentation for all this stuff is here:
> 
> 	http://www.knology.net/~lyle/rjudy
> 
> and the source tarball (which also includes those docs) is here:
> 
> 	http://www.knology.net/~lyle/rjudy-0.1.tar.gz
> 
> Very interesting stuff indeed (Judy, not my personal work). The 
> "JudyHash" class is still pretty rough by anyone's measure (i.e. 
> probably lots of opportunities for optimization) but it's already 
> consistently beating Ruby's Hash (in my admittedly limited benchmarking 
> tests). If you're interested in playing with this, I could use your help 
> in coming up with more challenging and meaningful benchmarks, as well as 
> examples. Also note that I haven't implemented all of Hash's methods 
> yet, so it's not yet a "drop-in" replacement for Hash.
> 
> Have fun!
> 
> Lyle
> 
> 
-- 
~transami