http://www.rubygarden.org/ruby?RubyNews/2004-12-06
Ruby Weekly News 6th - 12th December 2004
···
-----------------------------------------
A summary of the week's activity on the ruby-talk mailing list / the
comp.lang.ruby newsgroup. This summary is brought to you by Tim Sutherland
(TimSuth).
Articles and Announcements
--------------------------
* [Duck Images Weekly News]
[whytheluckystiff] parodied the Ruby Weekly News in response to a
comment from Dave Burt that [last week's RubyNews] failed to
include the [Duck Images thread]. Your editor gets the last
laugh(?) though, the second post in that thread wasn't until the
6th of December, meaning it falls inside this week's summary. See
Threads for more duck news.
* [RMagick pre-requisite changes]
Tim Hunter gave a "heads up" that future versions of the image
library [RMagick] (a Ruby interface to ImageMagick and
GraphicsMagick) will no longer be tested with versions of
ImageMagick earlier than 6.0.0 and may cease to work with them.
* [ruby-dev summary]
SASADA Koichi posted the latest English summary of the Japanese
list ruby-dev, covering messages 24959-25044.
* [RSS, Ruby, and the Web]
Tom Copeland reported that this month's Dr. Dobb's Journal has an
article by Dave Thomas on [RSS, Ruby, and the Web].
(Pay-subscription required to view the article on the web.)
* [Dynamic Java: Sun explores dynamic languages]
James Britt noticed that Sun is [exploring] how to better support
dynamic languages on the Java platform. There was a meeting which
included creators/maintainers from Perl, Python, Jython, Groovy
and Parrot. No Ruby representative, but Ruby will benefit from any
improvements in this area.
* [Want to Write a Book?]
Dave Thomas wants to launch a series of books from the Pragmatic
Bookshelf called "Facets of Ruby". These will be small, focused,
technical books on different aspects of Ruby. He's looking for
writers for them - this is your opportunity to become an author!
"The intent is to create a series of books with a deeply practical
focus. We won't just document APIs. Instead, we want to show how
to get _value_ from those APIs---how to solve real-world problems.
The books will probably be 100-250 pages long, and full of code."
* [A neat article on Rails performance...]
Tom Copeland drew the group's attention to an article [Session
Container Performance in Ruby on Rails] by "Scott Barron of
EliteJournal fame".
* [Development Assistance]
Austin Ziegler asked for volunteers to help enhance some of the
libraries he maintains: MIME::Types, Diff::LCS and PDF::Writer.
Threads
-------
Interesting threads this week included:
[Duck images]
-------------
Dave Burt wrote:
"Phil Tomson recently suggested developing a duck image to represent ruby
instead of the standard red stone thing.
Nikolai Weibull said this has been proposed before, but copyright
encumbrance has been an issue."
The duck, of course, refers to DuckTyping (coined by Dave Thomas), the
notion that the "type" of an object in Ruby should be seen in terms of the
capabilities and methods it supports rather than its class - if it walks
like a duck and quacks like a duck then it's a duck. (This is a well-known
saying in the English language.)
Dave Burt continued, announcing that whytheluckystiff had heard the cries
for help and used his artistic skills to create [The Only Copyrightless
Duck In Recent History].
The thread began with a small ASCII-art version of whytheluckystiff's
duck. Dave also posted a larger version using a short program he wrote
(img2ascii.rb) that used the [ruby-gd] library to automatically convert
the original image to ASCII. T. Onoma gave an alternative that was
constructed with [Jave] (Java ASCII Versatile Editor).
whytheluckystiff:
"I'm amazed at the progress that has been made in just the last 12
hours. If you'd like to start using any of these ducks, in the form of
a one-line signature, here's a DRb line:
ruby -rdrb -e
'DRb.start_service;duck=DRbObject.new(nil,
"druby://whytheluckystiff.net:6503");puts duck.daves'
Several other ducks are available at this service, try "puts duck.toms"
or "puts duck.on_the_water". For a complete list: "puts duck.list".
Think of it. In time, we could amass ducks to use them as currency on
the global markets. I think we can take Switzerland."
Combining duck images with the idea of Ruby code in signatures for email
and newsgroups (see the Previous RubyNews), Florian Frank gave three lines
of Ruby that produce an animated duck swimming on water and quacking. Many
people began going back and forth making it shorter. Jannis Harder posted
one in 108 characters:
i=1;loop{puts"\e[2J\e[;11H_\n%9s(*)____,\n%9s(` =~~/
#{'~^~'[i%=2,2]*9}"%[i>0?'<':'Quack! >',''];i+=sleep 1}
[Ruby (quiz?) simulation idea]
------------------------------
Hal Fulton had an idea for a future Ruby Quiz: write a program that models
a population of living creatures (similar to Conway's Life) as a grid of
squares with moving critters who can mate and produce offspring with
different genes. The program would determine when (if ever?) the genotype
frequencies of the population stabilised, using two different methods - by
running the simulation and also by using mathematics to predict the time
when equilibrium occurs. James Edward Gray II (the Ruby Quiz organiser)
thought that coming up with the mathematics could be left for
"extra-credit", saying "Some of us are easily pleased and would be content
watching little dots move around and multiply."
Brian Schröder had heard of an example of evolution using bats:
"I'd like to propose something a bit different that stresses the fact that
evolution is _not_ survival of the _strongest_ but survival of the _fittest
population_.
...
A bat may share the blood it has gathered through the night with another bat
that had no success. But why should it? If it shares, it needs to gather
successfully the next night, otherwise it will starve. So it diminusishes its
strength and helps a rival, whose genes will have a better chance to spread.
Wouldn't it be better off being egoistic and increasing its survival
possibility?
In practice, the bats developed some kind of "tit for tat" algorithm. So it is
_for the population with this trait_ an evolutionary positive trait to be
altruistic."
Ducks, bats, [foxes]! What other animals will be co-opted for nefarious
Ruby uses next?
[[SUMMARY] Crosswords (#10)]
----------------------------
James Edward Gray II summarised the solutions to last week's Ruby
Quiz (turning a crossword layout description into an ASCII-art
format). One interesting solution was Pit Capitain's, whose code
includes a method String#gsub2! which uses two-dimensional regular
expressions!
[[QUIZ] Learning Tic-Tac-Toe (#11)]
-----------------------------------
The latest installment in the adventures of [Ruby Quiz] began with our
narrator (James Edward Gray II)...
"This week's Ruby Quiz is to implement an AI for playing Tic-Tac-Toe, with a
catch: You're not allowed to embed any knowledge of the game into your
creation beyond how to make legal moves and recognizing that it has won or
lost.
Your program is expected to "learn" from the games it plays, until it masters
the game and can play flawlessly."
Jannis Harder posted a special signature for the occasion. You'll have to
run it to see what it does!
"bp6siZmijp5CiZlCiW5CgAAChpbiiZYiiZZCi5aCZ2bs".unpack("m")[0].
unpack("C*").map{|x|x.chr}.join.unpack("B*")[0].scan(/.{24}/){i=7
$&.scan(/..../){print"\e[3#{i-=1};1;40m ";$&.each_byte{|z|
print" #"[z-?0,1]*2}};puts"\e[0m"}
People posted their solutions under the same thread.
[IOWA book ideas]
-----------------
Stefan Schmiedl received positive feedback on his idea of writing a book
on the [IOWA] web application framework. He invited more comments on what
chapters people want in the book, listing some ideas he had.
[Wiki Spam Report]
------------------
Jim Weirich reported on the status of efforts to free the RubyGarden Wiki
from spam.
"Spammers are automatically routed to a wiki tarpit. The tarpit is an
(almost) exact copy of the real RubyGarden wiki. Making changes to
the tarpit looks as if you are making changes to the real wiki. And
since spammers get their pages from the wiki, it looks like (to them)
that they have successfully spammed our site."
This technique appears to be working very well.
[Hash freezes String keys are returns copy]
-------------------------------------------
Michael Neumann noticed that Hashes seem to behave differently with keys
that are Strings compared to other objects. If you try to get back the
String (e.g. with Hash#each or Hash#keys) a frozen-copy of the original
String is returned.
ts explained:
"this is made volontary for efficienty : otherwise each time that you
modify an object, used as a key, ruby will need to re-hash the hash if you
don't want to have strange result like the example that I've given
In reality when you write
a = "test"
hash[a] = "test"
the key and `a' share the same string, but `a' is marked copy-on-write"
Robert Klemme added:
"Yes, it's a special optimization for string keys. You can get your original
out if you freeze it before putting it into the hash. 
In fact, that
might be a performance optimization if you put *a lot* string keys into the
hash.
Because copying an instance is relatively expensive this pattern was not
adopted generally, i.e. you have to take care of Array and other keys
yourself. Note also, that you need to rehash if you change your array
instance after using it as Hash key."
New Releases
------------
* [RubyGems 0.8.3]
Jim Weirich announced the latest version of the [RubyGems] package
management system, fixing some annoying bugs, including a
workaround for the "string contains null byte" error several
people have reported seeing. Over 150 Ruby libraries or
applications are now available as gems.
* [ParseTree 1.3.0]
Ryan Davis wrote "[ParseTree] is a C extension (using RubyInline)
that extracts the parse tree for an entire class or a specific
method and returns it as a s-expression (aka sexp) using ruby's
arrays, strings, symbols, and integers." This release features
improved debugging messages and more nodes.
* [RubyScript2Exe 0.2.0]
Erik Veenstra updated [RubyScript2Exe]. This is a tool that
transforms a Ruby program into a single executable that includes
it along with the Ruby interpreter and necessary libraries,
simplifying deployment. It works in Windows and Linux. There was
some discussion on how to make this work with libraries that are
loaded with RubyGems.
* [Ruby/Extensions v0.6.0]
Gavin Sinclair was pleased to announce a new version of
[Ruby/Extensions], a set of additional methods for Ruby's standard
classes. New methods in this release include Array#rand for
selecting a random item from an Array, Array#one? and Array#none?.
require_relative was also added.
* [RPA completion for bash: 12/08/04]
Brian Schröder issued an improved [RPA Completion], a tool that
allows the bash shell to do tab-completion for RPA packages.
Within an hour of the announcement, Mauricio Fernández had
included the new version in RPA. An interesting feature of the
[RPA Completion homepage] is an animated image at the top which
demonstrates the use of RPA Completion. This is something that
other developers may find useful for their sites.
* [Jabber-RPC] [Jabber-RPC 0.1.0]
Massimiliano Mirra created a new library called [Jabber-RPC]. This
makes it easy to do RPC (remote-procedure-calls) over the Jabber
instant-messaging system. An update was later [announced], fixing
the example code and removing the dependency on expat.
Subsequently, version 0.1.0 was released with further changes.
* [ruby-sphere-0.1.0]
Daigo Tomono announced the first release of [ruby-sphere], a set
of libraries and tools for calculating the apparent position of
stars. This can be used for planning astronomical observations.
* [TeX::Hyphen 0.4.0]
Austin Ziegler had great pleasure in announcing a new version of
[TeX::Hyphen]. This is the last planned release of the library - a
replacement will be created to enable support of non-US
hyphenation definitions.
* [Nitro 0.6.0]
George Moschovitis announced a preview of the next version of the
[Nitro] web application framework. George invited people to email
him concerning the new logo (see the top of the [Nitro homepage]).
* [DBus/Ruby 0.1.7] [DBus/Ruby 0.1.8]
Leon Breedt fixed some bugs that could result in crashes in
[DBus/Ruby], a Ruby interface to the D-BUS message bus system.
* [FreeRIDE 0.9.2]
Laurent Julliard announced version 0.9.2 of the Free Ruby IDE
[FreeRIDE]. A number of bugs have been fixed. In the thread Curt
Hibbs lists possible enhancements that the community could
contribute to FreeRIDE.
* [ruby-growl]
Eric Hodel created [ruby-growl], a platform-independent system for
generating [Growl] messages. Growl is a notification system for
MacOS X. Applications use it to display messages on the screen.
* [vflow 0.2 beta]
jm wrote "[Vflow] is a netflow processing library for ruby similar
to Cflow (perl) and pyflowtool (python) for use with flow-tools".
Stability problems have been fixed in this release.
