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.

• Internet Problem Solving Contest

James Edward Gray II conferred, “As the resident programming challenge junkie, I feel the need to point out all the cool contests when they come up.”

The Internet Problem Solving Contest has opened registrations for their event on May 13th.

“The contest generally involves around eight problems most of which will have easy and hard variations. The format is that they describe the problem and provide the input. All they want back is the output, so you can use any tools you like.”

• Seeing Metaclasses Clearly

why the lucky stiff wrote an article on metaclasses “(aka virtual classes or metaobjects), since they still lurk under a shroud of fear and enigma.”

A great many replies ensued, some arguing about the use of the word “metaclass”. Lyndon Samson pointed to a post by Matz from a couple of years ago that says Ruby does not have meta-classes (maybe the only one is Class), however every object has a hidden “meta-object” which is revealed by “singleton class notation”, i.e. class << foo; ...; end

Regardless of which word you use, _why’s article is very interesting.

• Formal presentation proposals now being accepted for RubyConf 2005

On behalf of Ruby Central, Inc., David A. Black announced that formal presentation proposals for RubyConf 2005 are now being accepted.

“*** PLEASE NOTE *** that you must submit a formal proposal, even if you submitted a preliminary proposal when you preregistered.”

Submissions are open until May 27, 2005.

• Conference Hotel/Venue info for RubyConf 2005

David also announced venue information for RubyConf 2005. The conference Hotel is Lafayette Hotel & Suites in San Diego. A block of rooms has been reserved for $79.99 (+tax) per night for October 13, 14 and 15.

“Pre-registration has been pretty massive compared to previous years. We’ve set aside an accordingly large number of rooms, but would still advise you to make reservations early.”

• boulder_denver.rb

Ara.T.Howard: “you know the drill – this is a call for boulder/denver rubyists to get together and talk shop. drop me a note if you’re interested and i’ll put together a list and plan a meeting over coffee, beers, or both ;-)”

Lee Marlow recalled a thread about this in February on the Rails list. Someone had volunteered office space for the meetings too.

David Heinemeier Hansson announcing a new feature of Rails 0.12.0:

The time had come to butcher the piggy-back query and introduce real association loading through outer joins. Behold, the glorious eager loading of associations that makes it silly easy to fetch not 1, 2, but unlimited associations alongside any record in a single query. Turning 50 database queries into 1 never felt this good.

apache /fcgi: prevent starting of multiple fcgi processes

benny was using ruby-fcgi under Apache 1.3x. Under heavy load, Apache would create extra fcgi processes. This was a problem since benny was caching some data in the main process that he wanted to share between all requests.

FastCgiServer -processes 1
FastCgiConfig -minProcesses 1 -maxProcesses 1 

Saynatkari added “In general, I would have to waggle my finger in warning against such practice :)”

ruby-dev summary 25962-26010

Masayoshi Takahashi posted the summary of the Japanese mailing list ruby-dev.

Matz will be releasing Ruby 1.8.3 shortly, so contributors “who want to update their libraries should commit their patches ASAP.”

uninstalling earlier versions

Lionel Thiry asked if there was a way to uninstall all RubyGems on his system, apart from the latest versions and their dependencies.

Chad Fowler explained that it’s as easy as gem cleanup.

RUBY port to HPUX 64-bit PA-RISC 11.11

Jon Miller was looking for a binary distribution of Ruby for the HPUX operating system.

Jamis Buck said that he used HPUX at his previous job. As far as he knew, there was no pre-built binary. Furthermore, he could not enable Ruby’s pthread support on that platform – attempting to do so resulted in the build process crashing.

Alexey Verkhovsky tried the latest stable snapshot, and found that it does now work with --enable-pthread.

Jamis: “Wow, yes, this is fantastic news.”

accessor for Class Variable

Leonardo Francalanci had some code similar to the following

class Outing < ActiveRecord::Base
  @@planningList = [ "YES", "NO", "YES/NO"] 
end

Nicholas Seckar said that Rails provides a cattr_reader for this purpose.

class Outing < ActiveRecord::Base
  @@planningList = [ "YES", "NO", "YES/NO"] 

  cattr_reader :planningList
end

As an alternative, Robert Klemme suggested using a class instance variable.

class Outing < ActiveRecord::Base
  @planningList = [ "YES", "NO", "YES/NO"]

  class << self
    attr_reader :planningList
  end
end

Idea for Ruby Quiz - Su Doku solver

Lyndon Samson had an idea for a future Ruby Quiz. Su Doku is a logic puzzle, made up of a 9×9 grid, which is then organised into 9 boxes (each of which contains 9 squares).

Some of the squares contain numbers. To solve the puzzle, you must fill in the rest of the squares so “every row, every column, and every box contains the digits one to nine”.

Douglas Livingstone suggested making the quiz problem about writing a program to generate new puzzles, rather than solving them.

Bill Guindon found a quote from the creator of the game, Wayne Gould, who indicated that his program that creates new So Doku puzzles was written over 6 years. “If somebody does this in 3 days with Ruby, it’s probably gonna make this guy cry.”

accessing a ms exchange server

Peña, Botp was looking for advice on how to write Ruby code that accesses/edits the directory of a Microsoft Exchange server.

Ira Burton has managed this via LDAP; “It works like a champ!”

HighLine (#29)

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

“When you stop and think about it, methods like gets(), while handy, are still pretty low level.”

age = ask("What is your age?", Integer, :within => 0..105)

Francis Hwang cast eyes towards his EasyPrompt library, which does this, more or less. No matter! As Dave Burt said, “I think it’s a good one for any newbies out there to have a shot at. Reinventing wheels is a good thing to do for the purpose of learning to program.”

James later added “I myself am eternally grateful to all the people who work the quizzes and submit ideas to me. Without all the wonderful help, I would be sunk. Thanks so much!”

“The Ruby Quiz site has become a killer resource for just reading interesting code, if I do say so myself. There are some really great idioms in the solutions all over that site.”

Obtaining Hal's "The Ruby Way" in the UK

Glenn Smith tried ordering “The Ruby Way” from Amazon. After 6 weeks they told him they were unable to get a copy.

Help!

There were some suggestions of places to find second hand copies, plus a post from the book’s author, Hal Fulton.

He noted that the book is available online if you buy a subscription at O’Reilly’s Safari.

translation of ruby/tk?

Tom Nakamura couldn’t find English documentation for Ruby/Tk. Does it exist, or is there only Japanese documentation?

Benjamin Peterson said he’d posted a rough translation of the Japanese docs.

Question: Time efficiency of Array <<

Peter Suk wanted to know the time complexity of the Array#<< method. (In its simplest form, it adds an object to the end of the Array.)

Eric Hodel pointed out the method’s implementation at rb_ary_store in array.c, which showed that the underlying capacity of the Array is increased by 50% (multiplied by 1.5) when the size reaches its capacity.

3Cheers4David

Trans exclaimed “Three cheers for David A. Black. For all that he’s given to the Ruby community, from creating RCRchive.net to answering all those silly nube questions. We love you David :-)”

Ryan Leavengood added “Don’t forget all the work he has done over the years setting up the RubyConf, along with the other RubyConf organizers. We all appreciate your effort guys.”

Chris Pine: “Hey, while we’re at it, there’s always ts! (What does the ‘ts’ mean, Guy?) He’s also been a huge help over the years. And there are others: why, DHH, and pragdave have all made huge waves in our little (but growing!) pool.”

the Ruby Programming Shop

pat eyler announced the “Ruby Programming Shop”.

It’s no secret that there is a lot of Ruby code out there that needs to be cleaned up (it’s old, untested, undocumented, and maybe even abandoned). The RPS povides a way to ‘rescue’ that code and make it shine. We’ll limit ourselves to free software, and will contact the original author (when possible) to get his/her blessing.

“Right now, we need to flesh out our list of libraries to work on, and select a library for May/June. Come on in, sit down, and help make Ruby shine!”

RubyInline 3.3.0 Released - now with packaging support

Ryan Davis slipped out the latest RubyInline release. It allows you to embed C and C++ code directly within Ruby source files.

Support for RubyGems and Rake was added.

ParseTree 1.3.5

Ryan Davis intoned, “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.”

Dynamic exception handling was added, as was an option to help with core classes. A bug in the gemspec was also fixed.

webgen 0.3.3

Thomas Leitner introduced webgen 0.3.3, a tool that generates web pages from page description and template files.

Major changes include improved logging, a better command-line interface and bug fixes.

RubyLexer 0.6.0

vikkous was pleased to announce RubyLexer 0.6.0, a “standalone lexer of ruby in ruby”. It can tokenize almost all Ruby source code that works with Ruby 1.8. There was some discussion, and vikkous said that the advantage of RubyLexer over the lexer in irb was that the former was more complete.

iTunesTagger.rb 0.1

Scott Parkerson posted a script that lets you treat the “grouping” field in iTunes as a comma-separated list of tags.

“This can aid in creating smart playlists. Trust me.”

Stemmer 1.0.1 - Porter Stemmer Gem

Matt Mower released a RubyGem containing an implementation of the Porter word stemming algorithm. (To turn e.g. “testing” into “test”.)

He thanked Ray Pereda for porting the original code from Perl to Ruby.

Reg 0.4.0

vikkous announced the first version of Reg, “Ruby Extended Grammar”. It is a library providing regexp-like pattern matching for a variety of data structures, particularly Array, Hash and Object structures – not just Strings.

For example, +[Array, Integer] matches an Array containing exactly two elements, the first of which is another Array, the second an Integer.

Ruby/Odeum 0.2.1 (RubyGems Enabled)

Zed A. Shaw released a RubyGem for Ruby/Odeum, a binding to the QDBM Odeum inverted index library. (To efficiently search documents for words.)

A bug was also fixed.

Thanks to Jeremy Hinegardner for helping with the gemification.

Ruby-FLTK 0.9.1

Jeremy Henty posted his first release as the new maintainer of Ruby-FLTK – the bindings to the FLTK GUI library.

Thanks to Jeremy for volunteering to take over this project!

Rails 0.12.0: Eager associations, new Base.find API, assertions revisited, more Ajax!

David Heinemeier Hansson let another major Rails release out of the bag.

Rails now has “real association loading through outer joins.”

This means that a single query can fetch any number of associations alongside a record.

The following example was given,

# Turning N+1 queries into 1
for post in Post.find(:all, :include => [ :author, :comments ])
   puts "Post:            " + post.title
   puts "Written by:      " + post.author.name
   puts "Last comment on: " + post.comments.first.created_on
end 

The API for Base.find has been enhanced to match. For example,

Person.find(:all, :conditions => [ "category IN (?)", categories],
    :limit => 50)

Another major feature of the release was better Ajax support. It’s now easier to develop sites which provide a rich interface to Javascript-enabled browsers while still working when Javascript is not available.

This release of Rails is also fully backwards compatible with the previous version (0.11.1). Nice one!

Typo 2.0

Tobias Luetke was proud to announce version 2.0 of his web log software.

“What started as a toy project while I was waiting for a client at starbucks now became a prestige open source project with tons of modern features a dedicated dev team and even its own hosting service!”

New features include a web administrative interface, spam protection (thanks to Patrick Lenz), “Ajax galore”, permalinks, and more.

Rails 0.12.1: No major update without a bit of pain

David Heinemeier Hansson: “There’s nothing like pushing a new major update in order to find bugs in the code when its exposed to a couple of hundred working applications.”

That meant the release of Rails 0.12.1 to fix bugs that were found in the 0.12.0 version.

gem install rails --include-dependencies

(Easy, isn’t it?)