Ruby Weekly News

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

• Ruby Internship Request (RIR)

Shalev NessAiver is looking for an internship over the summer, preferably doing Ruby web programming. “My primary goal in seeking this internship is to gain more experience. Specifically, I would like to gain more experience in the area of web/interface design.”

• Hamburg.rb meeting...

Stephan Kämper announced that Hamburg (in Germany) now has a Ruby User Group. The first meeting is on April 6, 2005.

• Ruby RDF-Redland

Dominic Sisneros hasn’t had much time lately to work on RDF-Redland (a Ruby binding for the Redland Application Framework – related to the “semantic web” idea). His job has meant he’s travelling around, with a Windows laptop, but he hasn’t been able to build RDF-Redland on a Windows system.

He plans to do more work on it, as soon as he can get it to compile. Help wanted!

• IORCC 2005 entries

Vincent Foley noted that the IORCC 2005 entries have been put online. IORCC is the International Obfuscated Ruby Coding Contest. Check out the madness.

• 2005 IORCC PC Voting is now OPEN!

Todd Nathan announced that the People’s Choice voting for the IORCC was open. Anyone may vote on the entries they think are best (according to the guidelines).

• Translation into spanish of Ruby Quiz

James Edward Gray II shared the news that Imobach González Sosa will be translating each week’s Ruby Quiz into Spanish.

• TRUG 3 April 2005 Meeting

Mike Stok announced that the Toronto Ruby User Group was having a meeting on April 3, 2005. If this is the first you’ve heard of it, sorry but you missed the meeting!

• libxml and libxslt CVS

Trans adopted the libxml2 and libxslt libraries, which appeared to be abandoned by the previous maintainer. They’re now part of the XML:Tools project.

I’m going to be lazy and give it to the entire emerald 0.1 thread.

SOAP Server WSDL generation

Patrick Hurley had successfully set up a Ruby client and server for SOAP. (A protocol for remote procedure calls – web services.)

In both cases he had to tell the SOAP library which methods the interface should provide. “Using ruby soap, can the server “auto discover” the methods in a particular class and expose them?”

A second question was as to whether a Ruby SOAP server could generate a WSDL file.

There was no response to the first question. For the second, Leon Breedt brought up Rail’s ActionWebService. It does WSDL generation but does need annotations to declare the types of method parameters and return values.

ruby-dev summary 25781-25961

Kazuo Saito posted the summary of the Japanese list ruby-dev.

It said that Matz brought up the idea for changing the way method search occurs. David A. Black clarified the comments with an example:

class C
  def process
    util        # will always call C#util, even if overridden
    self.util   # will call subclass's #util, if present
  end

  def util
  end
end 

Currently, util and self.util both do the same thing – they will call the subclass’ method if one exists.

Shiny balls with OpenGL

This thread provides some examples of OpenGL graphics implemented in Ruby.

SNIPPET: YamlToHtml.rb (Or; Yet Another YAML Addict prowls the night..)

Phlip wrote some code to convert YAML lists into HTML tables.

“The goal of the goals is to allow a Wiki-style web site convert YAML into simple tables, essentially the way some Wikis convert |nebulous|specifications| into tables.”

“But is the world ready for “YASTL Ain’t a Structured Transformation Language” yet?”

Best way to get latest ruby on OS X?

Dennis Roberts wanted to know the best way of getting the latest stable Ruby release on MacOS X. Darwinports seemed to be the answer.

Modifying boolean values

Florian Gross explained that in Ruby, nil and false are “false”, and every other object is “true”.

So it’s easy to make an object behave like true (you don’t need to do anything), however it is not possible to have one which behaves like false. Understanding why requires some knowledge of how the Ruby interpreter works.

Every Ruby object is represented by a VALUE, which is an unsigned long. Some VALUEs correspond to addresses, while others (like nil and false) are “immediate” objects.

Boolean truth is evaluated in the interpreter via the RTEST macro, which simply checks if the VALUE is either the nil or false special constant.

Christoph referred to a patch he wrote three years ago which added a “false flag” to objects, allowing users to define their own boolean values without sacrificing performance.

ruby lib that will receive email

Peña, Botp asked whether there were Ruby libraries for receiving email.

Florian Gross said that Net::POP and Net::IMAP from Ruby’s standard library could be used here, and Shalev NessAiver said that ActionMailer from Rails was recently extended to deal with retrieving mail.

Peña clarified that they wanted e.g. an IMAP server written in Ruby, not a client. Aredridel had previously thought of using the EXIM mail server design in creating a Ruby mail server.

Glenn Parker nodded, “It sounds like a fun project to me, too. It might also be fun to have pure (or mostly pure) Ruby servers for LDAP, DNS, FTP, NIS, SSH, telnet, syslog, crontab, NFS…”

Last Chance 2005 IORCC Entries

Todd Nathan warned that your last chance for entering the 2005 International Obfuscated Ruby Coding Contest (IORCC) was nearing. (You missed it!)

Phil Tomson remarked on the number of sponsors and prizes the IORCC had managed to get, and wondered whether we could run a IERCC (“International Elegant Ruby Code contest”) or BRICC (“Beautiful Ruby International Code Contest”).

Todd said that this is already being worked on.

emerald 0.1

Matz wrote:

I’m pleased to announce you the first public release of emerald at

http://rubyurl.com/b5JtE

Emerald is an object oriented language with constraints and logic features, inspired from prolog, Oz, CSP and Hyper/J.

I started this as an hack since ruby is becoming less fun. It will not be as good as ruby, but please try it out while we wait for Rite.

Hal Fulton responded, “Very nice… but will it scale?”

Tom Copeland:

With this language, Ruby is fin-ished.

Now all we can do is flounder about.

I feel gill-ty for recommending Ruby now.

Emerald will be fast; if anyone can tuna language, it’s Matz.

The puns just got worse from there ;-)

PS: Matz posted his message on April 1st.

attr :<symbol>?

Luke Renn had seen code like attr :foo when using ActiveRecord. He wanted to know what the name for them was, and how he could write his own things like attr. Were they just class methods?

John Wilger confirmed that attr is indeed simply a class method. “In Ruby (unlike many other languages) the code that defines a class is much more than just a “definition”. The code between “class Foo … end” is executed just like any other part of your program.”

James Britt and Florian Gross posted bits of code that define new methods like attr, and there was some discussion of the differences between their implementations. (eval vs define_method.)

Open letter to anyone developing a Ruby IDE

Adelle Hartley had some ideas for adding a heuristic to do “intellisense” or “autocomplete” in Ruby IDEs.

There was discussion around existing solutions used in IDEs. Rob reminded the group of a solution he came up with that has been discussed previously in Ruby Weekly News. It’s still a cool idea, so is worth repeating:

“For completion I infer the possible classes of a variable, based on what methods have already been called on it. Then I provide a popup of the combined set of methods available for those classes, i.e. if it quacks like a duck, it will probably waddle like one two.”

Another technique is to rely on actually executing code before method information is available. One way to achieve this is through running unit tests on the code.

PDF Writer UTF-8 Support

Brian Schröder was having difficulting getting PDF::Writer to work with his UTF-8 text.

The library’s author, Austin Ziegler, explained that this wasn’t an area PDF::Writer had addressed yet, but there is a workaround that involves some effort.

Active Record and different field names

JZ was using ActiveRecord with Rails, but had tables that didn’t use id for their primary keys. How do you tell ActiveRecord which field it should use?

David Heinemeier Hansson said that set_primary_key should be used in this case.

Please tell me what this means? self.<method> in a class

Glenn Smith asked what def self.foo meant in the following code:

class Test
  def foo
  end

  def Test.foo
  end

  def self.foo
  end
end 

David Corbin explained that it was redefining Test.foo.

Robert Klemme noted that the reason why it’s better to write self.foo instead of Test.foo is that it allows you to change the name of the class in the future without having to modify the method declarations.

Code Cleaning (#26)

James Edward Gray II posted this week’s Ruby Quiz.

I’m always very vocal about how Ruby Quiz isn’t interested in golf and obfuscation. It’s my own private fight for clean code.

To be fair though, you can really learn a lot from practices like golf and obfuscation. It’ll teach you a surprising number of details about the inner workings of your language of choice. Still principals are principals and if I bend, word will quickly get out that I’ve given up the fight. Can’t allow that!

Here’s my compromise.

This week’s challenge is to utterly clean some famous examples of compressed Ruby code. Refactor the code until it’s as readable as possible, whatever that means to you.

Poor efficency of Ruby...

JZ ran a Rails application as a CGI and found performance was poor. David Heinemeier Hansson explained that he should use FastCGI instead.

The reason why PHP performs reasonably under CGI and Rails does not is that Rails does quite a bit of initialisation – for example reflecting over database tables to set up the ORM (Object-Relational Mapper). If you use CGI, Rails has to perform this initialisation for every single request.

With FastCGI, it is done just once.

Getting Ruby approved

Joe Van Dyk was “trying to get Ruby added to one of the “supported” OSS tools at Boeing”. Jim Freeze posted what he’d learnt from his (successful) attempt to introduce Ruby to a company he was working at.

There were almost 50 articles in the thread, with many people contributing their ideas.

zip a directory, unzip a zip file

itsme213 wanted to write Ruby code that zips up a directory, and can then unzip it.

Stefan Lang suggested the archive-tar-minitar library, and Thomas Sondergaard mentioned his own library, rubyzip.

An example of zipping up some directories using rubyzip:

Zip::ZipFile::open("all.zip", true) { |zf|
  Dir['{test,lib}/**/*'].each { |f| zf.add(f, f) }
} 

MySQL under latest one-click installer

R. Mark Volkmann was finding it difficult to getting Ruby on Windows to work with MySQL. Lothar Scholz suggested he use the pure-Ruby MySQL client library, rather than trying to install the one that wraps the C library.

James Britt posted instructions for how to do this, and the original poster managed to get everything working.

Ruby performance question

Jaypee benchmarked the following code on a 1GHz G4 and on dual 2GHz G5s, both with the same version of Ruby and 1GB RAM.

class Integer
  def factorial
    (1..self).inject(1) { |f, n| f * n }
  end
end

puts 100000.factorial

It was only 33% faster in the dual G5 system.

James Edward Gray II pointed out that Ruby was only using one CPU in the dual system. Even if the code was changed to use Threads, Ruby would still only use one CPU because Ruby uses its own user-land thread system.

Even so, with one 2GHz G5, the second system should be over twice as fast as the first. (Shalev NessAiver reported that the G5 has a much faster bus and memory speed than the G4.)

No further explanation was forthcoming.

ActiveState Ruby 1.8.2

Thursday asked if anyone knew whether ActiveState were interested in doing work on Ruby. They currently have “distributions” and support for Perl, Python and Tcl.

Pat Eyler spoke to them at OSCON last year. They would like their Komodo IDE to support debugging in Ruby, but don’t currently have in-house Ruby expertise.

Ruby Weekly News 21st - 27th March 2005

Yes, a thread starting with last week’s Ruby Weekly News. Be thankful that it isn’t this week’s! (A time machine written in Ruby?)

Last week’s Quote of the Week was Matz announcing that the YARV virtual machine would be merged into the main Ruby implementation this year.

After a few days with no comment, Tim Sutherland tried to stir up a reaction with “I’m surprised no-one has commented on this yet… I was expecting a chorus of “wow!”s.”

Nikolai Weibull said “wow! ”, and also questioned how YARV relates to Rite and Ruby 1.9. (Rite was intended to be “Ruby done Right”, a complete rewrite of the Ruby interpreter to get a faster implementation. The language would also change with Rite. The language changes are being implemented in Ruby 1.9, without the better implementation.)

Matz explained, “Since YARV engine would achieve what I wanted by complete rewrite, I’d call YARV merged 1.9 as Rite.”

There were comments on the possible benefits and disadvantages of merging YARV.

Getting process status

Joe Van Dyk had a process id, and wanted to get a Process::Status object for it. The goal was to be able to check whether the process was still running.

Leon Breedt said that you can check this via Process#kill(0, pid).

look-behind regexp ?

Shajith asked if there were plans to support “look-behind” in Ruby’s regular expression engine.

Matz said that the engine used in Ruby 1.9 (Oniguruma) already supports this.

Production Log Analyzer 1.1.0

Eric Hodel made the first public release of the Production Log Analyzer. It is used to analyse the logs of a web application, to determine which pages are taking up a lot of resources.

MuraveyWeb 0.2 -- tons of new stuff (Ruby on Rails CMS with a live demo)

Dmitry V. Sabanin added many new features to MuraveyWeb, a CMS (Content Management System) written with Ruby on Rails. New features include document revision management and a staging area for files.

color-tools 1.0.0

Austin Ziegler was pleased to announce the first release of color-tools. It provides support for the RGB and CMYK colour models, with “148 named RGB colours that are commonly supported and used in HTML, colour manipulation operations, and a monochromatic contrasting palette generator.”

It will be used in future PDF::Writer releases.

RubyGems 0.8.10

Jim Weirich announced a bug-fix release of RubyGems. An issue where it could become confused between different versions of the same library has been addressed.

MiniRubyWiki 1.0.0

Phlip announced an important milestone in MiniRubyWiki development: version 1.0.0. This is a Wiki implementation with “the most advanced emergent features available in wikidom. You can import raw text or html into wiki pages, execute commands to populate wiki pages, and you ran run, organize, and annotate thousands of pages of test resources.”

QtRuby 1.0.8/Korundum 3.4.0/KDevelop 3.2.0

Richard Dale let it be known that there were new QtRuby, Korundum and KDevelop releases. The first two are Ruby bindings for the Qt and KDE APIs, while the latter is an IDE. Bugs were fixed in the bindings. KDevelop includes Ruby support for features like creating GUIs graphically, debugging and a class browser.

KirbyBase 2.0

Jamey Cribbs released a new major version of KirbyBase, a small database management system that stores its data in plain-text files. The API has been changed to be more “Rubyish”. (For example, using blocks.) Jamey also thanked Hal Fulton for feedback on the previous release.

SimpleXML for you

Aleksi ported the PHP SimpleXML library to Ruby. James Britt suggested looking at the XmlSimple library, which is based on Perl’s XML::Simple.

FireRuby 0.2.1

Peter Wood fixed some bugs in FireRuby, a binding for the FireBird RDBMS.

Ruby-GetText-Package-0.8.1

Masao Mutoh updated the Ruby-GetText library. This provides Native Language Support (text in multiple languages etc.) and is based on GNU gettext. Bugs have been fixed and a new translation, pt_BR, has been added by Joao Pedrosa.

Amrita 1.0.2 + XML + amrita_id fix

Aredridel posted a patch to allow Amrita 1.0.2 to work with REXML. (New users should use Amrita2 instead.)

FastCST 0.6.5 (Mergerific Indexer Release)

Zed A. Shaw added a “whole whack” of features to his FastCST version control tool. There is now better safety and security, as well as merge features. The repository layout format has been changed, meaning that this release cannot be used with repositories created in earlier versions. Zed believes this will be the last such change for a while.

RMagick 1.7.4 released

Timothy Hunter released a new version of RMagick to enable it to work with the latest ImageMagick release (6.2.1). “RMagick is an interface to the ImageMagick and GraphicsMagick image processing libraries. Supports more than 80 image formats, including GIF, JPEG, PNG. Includes 2D drawing API.”