Ruby Weekly News 7th - 13th November 2005


#1

http://www.rubyweeklynews.org/20051113.html

Ruby Weekly News 7th - 13th November 2005

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

[Contribute to the next newsletter.]

Articles and Announcements

 * Why the Lucky Stiff (again!) on Noboto
 ----------------------------------------

   As Raymond B. intoned, the latest Noboto video-blog features
   Why the Lucky Stiff's soundtrack to Chapter 6 of the Poignant 

Guide -
“The Belljar, the Space, and My Daughter’s Organ Instructor”.
This follows the previous week’s interview with Why.

 * RubyForge milestone
 ---------------------

   Tom C. announced that RubyForge had reached 1000 hosted 

projects
with the addition of Joseph Tremblay’s Rolling Gemstone.

   "Here's to the next 1000 projects!"

 * Red: The Ruby Journal, a professional periodical for Ruby 

developers
----------------------------------------------------------------------

   M. Samuel "Flywheel" Streicher announced a commercial journal for 

Ruby
developers.

   | The journal, tentatively titled "Red," will be published 

monthly and
| will be distributed internationally as a stylish, high-quality,
60-
| page PDF. Each month, Red will focus on boosting the skills and
| productivity of all Ruby programmers-from novices to gurus-
| providing pragmatic, practical, insightful, hands-on, and
diverse
| advice and expertise.
|
| Contributors will be paid for material accepted and published
in the
| journal. Like other journals, all material will be vetted by
peers
| and experts prior to publication.

   Those interested in subscribing, writing articles, regular 

columns or
advertising are invited to contact Samuel.

   Bill G.: "Ok, 10 points for the most ambitious 1st post I've 

ever
seen on any mailing list".

   There was some discussion about the name of the journal. Pat 

Eyler
popularly suggested ‘Red Letter’, “for no other reason that every
time
you get your copy, it will be a red letter day”.

 * how the move from pdp-11 assembler to ruby took steve jenkins' 

breath
-----------------------------------------------------------------------
away
------

   This week SciRuby interviews Steve Jenkins, Principal Engineer at 

the
Jet Propulsion Laboratory of the California Institute of
Technology.

   "[SciRuby] What programming accomplishment are you most proud 

of?"

   | I wrote some code back in the early 1990s that ended up being 

used,
| at least as a design concept, in the engineering effort to save
the
| Galileo mission to Jupiter after the spacecraft’s high-gain
antenna
| failed to deploy. It wasn’t particularly advanced programming,
but
| it was in the right place at the right time. Solving that
problem is
| part of the reason the Deep Space Network converted to a TCP/IP
| network infrastructure when they did.

 * Ruby Forum
 ------------

   Andreas S. created web forums mirroring the ruby-talk and 

rails
mailing lists.

   There are now (at least) four ways to read and post: through the
   ruby-talk list, the comp.lang.ruby newsgroup, the
   gmane.comp.lang.ruby.general interface or the Ruby forum.

   See also Andreas' earlier post [Mailing list <-> web forum 

gateway].

 * Permathreads
 --------------

   James B. created the page [RubyTalkPermaThreads] on the 

RubyGarden
wiki to keep track of threads that keep popping up all the time.

   | I encourage folks with knowledge of particular areas to add
   | resources so that at least when certain (very) familiar topics 

rear
| their heads every few months people can avoid rehashing the
same
| basic stuff.

User Group News

 * Refresh Phoenix (AKA Not-quite Phoenix.rb)
 --------------------------------------------

   James B. announced the first "Refresh Phoenix" (Arizona) 

meeting,
“a community of designers and developers working to refresh the
creative, technical, and professional culture of Internet
developers
in the Phoenix metropolitan area” - held November 8th.

   The second meeting is on the 6th of December.

 * Ruby Group Meeting in Montreal
 --------------------------------

   David Vincelli announced a meeting on November 9th in Montreal, 

with a
presentation on Rails, and perhaps more.

 * new_haven.rb Unit Testing Slideshow now online
 ------------------------------------------------

   Gregory B. posted his slides on unit testing from the 

new_haven.rb
meeting (New Haven Ruby Brigade, in Connecticut, U.S.). The
Takahashi
method is here.

   He also said they're planning to start putting up audio 

recordings of
their meetings, and maybe run IRC during them.

 * Typo chat, BBQ dinner (Sunnyvale, CA), 11/10, 7 pm
 ----------------------------------------------------

   Rich M. forwarded a message announcing a meeting with Scott 

Laird,
“a developer for Typo (blog software written in Ruby on Rails)”
at a
BBQ Dinner in the San Francisco Bay Area.

Image of the Week

“Leaf”, by Jeff Kubina

What a pity you aren’t looking at the web view of this newsletter.
http://www.rubyweeklynews.org/20051113.html

(Send your suggestions in for next week’s image.)

Threads

Function Variable and Return Value References

Eric Hofreiter was confused about the semantics of variable passing
and
return values in Ruby, wondering in which case those were done by
reference or by value.

| At first, I thought variables were always pointers, and things such
as
| a = b meant that if you change a, you change b. It seems now that
this
| is in fact never the case.

Hal F. explained that Eric had a few misunderstandings concerning
variables, which except in cases of “immediate” objects do hold
references
to objects, and with assignment, which only binds a variable to an
object.

| So any operation that actually changes the object will behave as
you
| expect.

a = "Hello"
a = b
b << " there!"
puts a   # "Hello there!"
puts b   # "Hello there!"

| However, any operation that binds a variable to a new/different
object
| won’t show that effect.

a = "Hello"
a = b
b += " there!"
puts a   # "Hello"
puts b   # "Hello there!"

| You might think at first glance that x << y and x += y do the same
thing
| for strings. And indeed they result in the same value.
|
| But x += y is just syntax sugar for x = x + y (i.e., they mean
exactly
| the same thing). So += is actually an assignment, and thus doesn’t
| change an object-it just binds a variable to a new or different
object.

Eric M. added a line-by-line comparison between Hal’s example
and the
equivalent in C++, to illustrate the semantics of assignment, and
indicated that variables in Ruby are lightweight, which makes it easy
to
optimise them but difficult to get a reference to the variables
themselves.

Index and Query (#54)

This week’s Ruby Q. (by Lyndon S.) challenges you to build a
simple
indexer/query system for finding words in text documents.

As usual, anyone can take part and post their solution after the
48-hour
“no-spoiler” period, which is followed by discussions around the
different
approaches.

Numeric <=>

ChrisH asked why Numeric implements <=> so it returns 0 or nil,
rather
than the usual -1, 0 and 1, while it also includes Comparable. Eric
Hodel
replied that Numeric being an abstract class, its subclasses just
need to
override the spaceship operator appropriately, but the question
remained
why it should be implemented at all. As Robert K. said:

| Including Comparable is not a reason IMHO because that will break
either
| way (i.e. with missing <=> and with incomplete implemented <=>).

This was followed by a discussion about whether having the safety net
of a
partially implemented <=> was better than simply raising an
“undefined
method” error when performing a comparison (or a sort). The opinions
on
the subject were divided and no clear conclusion came out.

Rubyholic

“What’s rubyholic?”, asked Joe Van D…

JB Eriksson explained that it’s someone who consumes large quantities
of
rubyhol.

If you experience three or more of the following in the same 12-month
period, then you may be a rubyholic:

 * You write larger amounts of Ruby code, or over a longer period 

than
intended.
* Your Ruby coding interferes with family, friends, or job.
* You develop tolerance, meaning that over time it takes [more
concise
code] to satisfy you than it used to.
* You experience withdrawal, meaning that you have unpleasant
symptoms
if you stop coding Ruby.

If you’re ready to ask for help, then start by seeing if there is a
[rubyholics group] in your area. There you can share your experiences
with
others who are going through the same challenges.

Better way to build string

Marcus asked for a better way to write the following code:

def build_query_string(properties, prop_type)
result = “”

properties.each do |item|
if prop_type == “tag”
result += " #{item.name}=#{item.value}"
else
if result == “”
result = “?”
else
result += “&”
end
result += “#{item.name}=#{item.value}”
end
end

result
end

Peter E. gave a nice solution using map and join:

def build_query_string(properties, prop_type)
query = properties.map {|p| “#{p.name}=#{p.value}”}
case prop_type
when “tag”: (" " + query.join(" “))
else (”?" + query.join("&"))
end
end

In general, it’s clearer to use declarative methods like map and join
rather than each-with-side-effects.

RFC: Audio

Hans F. noticed a lot of people asking audio questions about Ruby,
and
felt that this was an area where Ruby still needs a lot of work.

To this end, he began working on wrapping “libsndfile, libsamplerate,
and
possibly portaudio. Combined with ladspar, midilib, and other ruby
audio
libs that exist, this should get us well on the way.”

He is likely to run the project under the SciRuby site. “About me:
I’m a
PhD student in Computer Science who finally gets to say that music
and
audio stuff is on-topic, as my research area is Computer Music.”

Hugh S. noted that Python has for some time included audio
libraries in
its standard library, and suggested these could be used for
inspiration.

ruby-dev summary 27542-27662

Kazuo Saito summarised the latest discussions from the Japanese list
ruby-dev.

Among the issues discussed was a request for people to test the 1.8.4
preview1 build and unit tests on a variety of platforms.

New Releases

setuidruby-1.0.0

Ara.T.Howard posted a program for running Ruby as a selectable user
on
unix systems, with e.g. setuidruby ahoward ./a.rb.

RubyCocoa 0.4.2

Kimura Wataru released RubyCocoa 0.4.2, the bindings to Mac OS X’s
Cocoa
framework.

It now works with Mac OS X 10.4 and 10.3, and continues to work on
10.2.
“Core Data” support was added.

Ruby Web Bench 0.0.0 (RWB)

Pat Eyler created a new web performance / load testing tool as an
alternative to Apache’s ab, featuring the ability to thrash a
weighted
list of URLs.

Bob H.: “This looks really quite handy-I think I’ve had the
same
issues as you have had with ab.”

0.0.1 and 0.0.2 were later released. The latter added warmup support.

Stomp Client Release

Brian McCallister released 1.0.0 of a client for “Stomp” (a
text-oriented
messaging protocol, “Message Oriented Middleware” if you will).

Jim F. asked how it was different to DRb, and Brian explained
“DRb is
a synchronous RPC style system whereas stomp is asynchronous message
passing (though you can ask for a reply).”

Net::DICT 0.9.0

Nikolai W. announced a client-side implementation of the
Dictionary
Server Protocol (RFC2229).

Ruby/ZOOM 0.2.2

Laurent S.'s Ruby/ZOOM was updated, fixing a couple of bugs
in
ZOOM::Query.

| Ruby/ZOOM provides a Ruby binding to the Z39.50 Object-Orientation
Model
| (ZOOM), an abstract object-oriented programming interface to a
subset of
| the services specified by the Z39.50 standard, also known as the
| international standard ISO 23950.

CommandLine-0.7.9 Update

Jim F.'s CommandLine library now features a lower-case gem name,
new
documentation and a refined API.

lockfile-1.4.0

Ara.T.Howard added a gem, and a method for atomically creating and
opening
a file, to lockfile, “a ruby library for creating NFS safe
lockfiles”.

TeSLa 0.2.0 is out

Obscured by code announced the release of TeSLa version 0.2.0. Among
many
changes, TeSLa is now able to handle Test-Driven Development by
failing
gracefully when a tested method doesn’t exist yet. A full release
article
can be found here.

TeSLa is a DSL devoted to unit testing.

eric3 3.8.0 released

Detlev Offenbach released eric3 version 3.8.0. eric3 is a Python and
Ruby
IDE written in Python.

KirbyBase 2.4

Jamey C. set out KirbyBase 2.4, a pure-Ruby database management
system
that uses plain-text files.

Memos and Blobs are now writable, many-many associations can be
defined,
the manual was extensively revised, and more.

Ezra Z.: “I really love kirbybase as a lightweight pure
ruby db.
Keep up the great work Jamie!”

Net::SSH 1.0.3

A Windows-specific maintenance release of Net::SSH fixes a problem
with
connections failing when the PuTTy pageant was not running.

Jamis B.'s Net::SSH is “a pure-Ruby implementation of the SSH2
client
protocol, allowing Ruby scripts to interact with remote processes via
SSH.”

Ruport 0.2.0

Gregory B. introduced the second version of Ruport, “the release
that
was just supposed to be minor bug fixes but exploded into a whole lot
more” (the API was completely redesigned).

This release was followed three days later by minor update 0.2.2.
This
update is a bug fix and clean up of the codebase.

Ruport is a pure-Ruby report generation framework.

SMC - State Machine Compiler v. 4.3.0

Charles Rapp announced the latest version of the State Machine
Compiler
(SMC) which takes a file describing a state machine and outputs code
to
implement it in a variety of languages, including Ruby.

Rails 1.0 RC4 (0.14.3): It’s the final countdown!

David Heinemeier H. announced the (hopefully) final preview of
Rails
before version 1.0.

[ TEST ME | TEST ME | TEST ME | TEST ME | TEST ME | TEST ME | TEST ME
]

| Comrades, we are so close to the goal that the relieve should be
| tastable. The mythical 1.0 release is now penned to be the very
next
| release once we rattle out the heinous bugs from this one. So we
need
| every man, woman, and child at work testing the living daylights
out of
| this final release candidate. Upgrade your apps, start new ones,
kick
| the tires, rev the engine, do it all!

Many additions were made, despite the last-preview status. They
include
the use of lighttpd in development mode if it is available
(automatically
run through script/server), script/plugin to help manage plugins,
more
ActiveRecord dynamic finder goodness, “extensions for association
collections” (so you can do e.g. account.people.my_method),
redirect_to
:back, and more.

Oh yeah, and upgrading is easier, so there are no excuses.

Now how about getting ready for some Rails Release Parties?


#2

In article removed_email_address@domain.invalid, Tim S. wrote:

http://www.rubyweeklynews.org/20051113.html
[…]
Function Variable and Return Value References

[…]

The two examples having “a = b” should be “b = a” instead.

Thanks to Derek Mahar for catching the error.