Ruby Weekly News 13th - 19th February 2006


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http://www.rubyweeklynews.org/20060219.html

Ruby Weekly News 13th - 19th February 2006

Ruby Weekly News is a summary of the week’s activity on the ruby-talk
mailing list / the comp.lang.ruby newsgroup / Ruby forum, brought to
you
by Tim S…

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Articles and Announcements

 * Rubuntu LiveCD I need vim/emacs configs!
 ------------------------------------------

   Ezra Z. is putting together a Linux LiveCD called 

Rubuntu,
that is Ruby and Rails centric.

   | What I really need some help with is killer ruby configs for 

vim,
| emacs and jedit. And anything else you would like to see
included,
| please drop me a note and any pointers you have for
configuration
| that would be best suited for this.

 * russian RUBY forum
 --------------------

   A Russian-language Ruby forum was announced by an anonymous 

person,
and Michael S. noted a Russian mailing list that has been
around
since 2002.

Threads

SAFE levels

During a discussion on tainting, David V. posted output from an
irb
session, including

irb(main):005:0> foo % “bar”
=> “bar\n”
irb(main):006:0> _.tainted?
=> true
irb(main):007:0>

He was asked what the “_” was about, and replied “irb automatically
populates the _ variable with the result of the last line executed.
__ is
two lines past, ___ three lines past.”

You actually need to set an option in ~/.irbrc to enable this, see
Irb/TipsAndTricks on the Rubygarden wiki for the details.

neuroimage software - scientific computing and visualization

Darren L. Weber asked about Matlab vs Ruby for scientific
programming.

I’m looking at Ruby for scripting/programming of scientific
computing
for neuroimaging. This includes time-series plots and analysis,
image
volume segmentation and rendering, surface modeling, visualization
and
morphing, and animating scalar and vector quanities on surfaces.
Also
linear algrebra methods and spatial transformations, almost any
scientific computation you can imagine, especially large scale
statistical analysis (including permutations).

There was a chorus of people saying Matlab is better for this area.
Chris
noted that Matlab is expensive, while Ruby is free, so if you can’t
afford
it, or just want to use open-source software, you should use …
Octave,
“the open source equivalent to Matlab”.

Darren himself listed some useful links for scientific programming in
Ruby; NArray library’s homepage, Ruby/GSL library’s homepage and
SciRuby.

couple quick questions about YARV

Joshua H. said “I know YARV is far from finished,” but what is
the
likely startup cost, and will existing Ruby extensions work?

Matz posted startup times for ruby1.8 and ruby.yarv. 0.009s vs
0.006s.
i.e. no increase in startup cost.

He also said that Ruby extensions can work currently, but “No promise
for
the future.”

stijn asked, as long as we were discussing YARV, how much speedup
could be
expected. “I’ve seen Koichi’s slides and they look impressive but if
I am
not mistaken the optimizations looked to be concerned with basic math
operations and so on.”

Matz: “YARV runs much faster on calls and basic operations. But it
runs
slower on eval()'ing. Ko1 is now working on it, I think.”

David V. wondered if this might just discourage people from
eval("…"), so they use define_method etc. instead.

“Is something like smalltalkish “clean” blocks being pondered to make
calls like define_method less prone to leak memory keeping local
scopes
from being GCed?”

Garbage collection schemes were also mentioned.

OT: Is this worth a try?

gregarican asked how people felt about the Eiffel language. Is it
worth
learning?

Jim W.:

I played around with Eiffel for 3 years before switching to Ruby.
In 6
months I wrote more Ruby code than in the entire 3 years of Eiffel.
Productivity is way higher in Ruby.

However, the concepts learned in Eiffel were valuable for me. No,
you
are probably not going to land your next big job because you know
Eiffel, but learning to use Eiffel well will help you write better
code
in any OO language, IMHO.

There was some discussion of Eiffel’s design-by-constract features by
“twenty closet Eiffel freaks” (wrote Logan C. with a smiley),
and
David V. said that Eiffel is the “prime example of a bondage and
discipline language. Which you might or might not like”.

Guido Kollerie noted that the Arachno Ruby IDE is written in Eiffel.

Adam S. suggested learning Io instead.

From the website, “Io is a small, prototype-based programming
language.
The ideas in Io are mostly inspired by Smalltalk (all values are
objects),
Self (prototype-based), NewtonScript (differential inheritance), Act1
(actors and futures for concurrency), LISP (code is a runtime
inspectable/modifiable tree) and Lua (small, embeddable).”

Adam:

It took me a few hits on their site before I really looked at it,
and
then a little longer to appreciate it, but once I did, wow.

Each language allows a different framework for solving a problem,
and
will enrich your understanding of all other languages through the
similarities and differences.

Writing Secure Web Services

Scott asked about creating a secure (encrypted / authenticated) web
service in Ruby.

Roland S.:

[an] idea is using wss4r with ActiveWebService. You can then
encrypt
and/or sign the requests/responses from both client and server.
WSS4R
uses certificates for signing and encryption. Another advantage is
that
it is conform to some web service specs, so you can use other
clients
like java or .NET.

(wss4r is a Ruby implementation of the WS-Security standards, and
built on
top of soap4r. Roland created wss4r.)

ActiveRecord or OG?

“Avid lurker” jansenh asked for advice on which ORM
(object-relational
mapper) to use: ActiveRecord (as used in Rails), or Og (as used with
Nitro).

The application was a web service that deals with data coming in,
stores
it in a database, applies business rules etc.

One obvious answer might be: “Try both…”, but I dont have the
capacity
to do that.

James B.: “Well, you probably do. They are both pretty
straightforward
to use.”

Wilson B. gave a great rule-of-thumb:

One way to decide is by choosing which of these two statements
seems
more `right’ to you.

  1. Ruby objects are wrappers around rows in my database.
  2. The database is where my Ruby objects go when they are sleepy.

#1 is ActiveRecord, #2 is ObjectGraph.

New Releases

Ruby GUI Debugger

mitchell created Mr. Guid, a GUI front-end to Ruby’s built-in
debugger,
using Ruby/Gtk2.

It already supports all the features of the underlying debug library,
and
looks very nice and usable.

FYI, “Mr. Guid” is a pseudo-acronym for Mitchell’s Ruby GUI Debugger.

Weft QDA 1.0.0 released

Alex F. announced the 1.0.0 release of Weft QDA, an “open-source
tool
for analysis of textual qualitative data”, for social anthropology,
sociology, etc.

“It can and has been used successfully for a wide variety of
real-life
research projects. it’s particularly suitable for teaching and
learning
CAQDAS (Computer-Assisted Qualitative Data Analysis)”.

lazy.rb 0.9.5 – transparent futures!

MenTaLguY introduced a new version of lazy.rb, featuring thread
safety and
“transparent futures”.

As well as the usual delayed evaluation:

x = promise { 3 + 5 } # in practice, some slow algorithm
p x # => #<Lazy::Promise computation=#Proc:...>
p x * 3 # => 24
p x # => 8

there are now `futures’, which are “blocks of code that are evaluated
immediately, but in a background thread.”

x = future { 3 + 5 }

all the while the block is being run in the background

do_something_else()

below will wait for the value to be ready

p x * 3 # => 24

“Again, silly for 3 + 5 perhaps, but I’m sure you can see how this
might
come in handy for more involved computations.”

Ruby/DBI 0.1.0: Not Dead Yet

Francis H.: “After a long, deep slumber of more than 18 months,
Ruby/DBI awakens and lumbers forward into the countryside. Rise,
Ruby/DBI,
rise! Strike terror deep in the hearts of Rubyists everywhere! Ahem.”

Michael N. has handed off the reins to Daniel B., Kirk
Haines,
Patrick M., and myself. This first release is fairly modest,
cleaning
up a few small bugs and doing lots of behind-the-scenese
reorganization.

SwitchTower 1.0.0

Jamis B. announced SwitchTower 1.0.0, “a utility that can execute
commands in parallel on multiple servers.”

An example use is for deploying a Rails application, especially if it
is
split over multiple servers.