Ruby Weekly News 17th - 23rd January 2005

http://www.rubygarden.org/ruby?RubyNews/2005-01-17

NB: This edition includes a "Quote of the Week" section, as suggested by
trans. Send in any interesting quotes you see to [e-mail] for next
week's RubyNews.


                   Ruby Weekly News 17th - 23rd January 2005
		   -----------------------------------------

   A summary of the week's activity on the ruby-talk mailing list / the
   comp.lang.ruby newsgroup, brought to you by [Tim Sutherland].

Articles and Announcements
--------------------------

     * [[Rails] ONLamp article on Rails] [2]

           Curt Hibbs wrote an excellent introduction to the [Rails] web
           application framework: [Rolling with Ruby on Rails]. It goes
           through the basics of installing Rails and then guides the reader
           into creating a simple cooking recipe website. The article was
           [covered on slashdot]; Tom Copland [reported] that the One-Click
           Ruby Installer was downloaded 1500 times that day, up from the
           usual 200-300.

     * [re-writing CD Baby from scratch in Ruby, using Rails]

           In related news, Derek Sivers [wrote an article] announcing that
           [CD Baby] - currently 90,000 lines of PHP and receiving 15,000
           unique visitors per day - will be rewritten to use Rails. "Now,
           with Rails, there are a team of passionate geniuses contributing
           to this web-making framework daily. It's small enough that you can
           stay on top of it, and watch this framework get more and more
           powerful by the week. Improvements that are pragmatic not
           political. People using it to make effective websites,
           contributing to the shared framework around it as they go. Why not
           take advantage of all this brilliant work?"

     * [Ruby Exam - unittest yourself]

           Simon Strandgaard wikified a set of "exam" questions about Ruby
           that were written some time ago by 'Imperator'. Test yourself at
           RubyExam.

     * [[Ruby Forum] Ruby Jobs category]

           Alexey Verkhovsky added a Ruby Jobs category to the [Ruby Forum].
           "Programmers: please brace yourselves for an avalanche of
           lucrative opportunities" "Employers: please create the
           aforementioned avalanche".

     * [Fwd: OSCON Call For Proposals Now Open]

           Chad Fowler forwarded the 2005 O'Reilly Open Source Convention
           call for participation announcement to the list and thought it
           would be great to have an energetic Ruby presence there. David
           Heinemeier Hansson has already submitted a proposal for a 3-hour
           [Rails] tutorial.

Quote of the Week
-----------------

   James Edward Gray II began the [summary] of last week's Ruby Quiz with the
   following...

  "Quiz creator Jim Weirich shared this wonderful little tidbit with me:
   
         True and slightly off topic story:
   
         The first time I wrote a version of this program, it was on a simple
         single board Z80 computer using a FORTH-like language to program it.
         I had seeded the program with a single animal (a mouse) and called my
         wife in to try it out.  I explained the program and she ran the
         program.  It printed out the words "Think of an animal ...", and then
         paused for a few seconds.  Then it asked "Is it a mouse?".  My wife
         turned to me with a look of absolute astonishment and said "HOW did it
         know that?".
   
         Yep, she was thinking of a mouse.
   
  Unfortunately, none of the submitted solutions were quite that all-knowing."

Threads
-------

   Interesting threads this week included:

  [Ruby Calibre Help]
  -------------------

   trans asked for help cleaning up, documenting and testing a project called
   Ruby Carats which will be a large library of additions to Ruby. This is
   half of his [Ruby Calibre] project - the other half being Ruby Facets, a
   collection of extensions to standard classes.

  [RubyScript2Exe and RubyGems]
  -----------------------------

   Erik Veenstra recently added support for RubyGems to RubyScript2Exe (a
   tool that transforms a Ruby program into a single stand-alone executable).
   He's done some testing "but not in "real" situations" and would like to
   know if anyone has successfully used RubyScript2Exe on an application that
   loads some libraries via RubyGems.

  [Bug#290705: ruby: Ruby is completly vivisected.]
  -------------------------------------------------

   Trevor Wennblom noticed that Ruby 1.8 on Debian GNU/Linux is split up into
   several dozen packages, and [reported this as a bug] to Debian. Two
   examples are the librexml-ruby1.8 and libdrb-ruby1.8 packages which must
   be installed for the 'rexml' and 'drb' libraries to be available, even
   though the latter are part of the standard Ruby 1.8 distribution.

   Austin Ziegler had witnessed the problems this can cause, "the RubyGems
   mailing list has gotten at least three reports of being unable to use
   RubyGems on Debian because libzlib-ruby hasn't been installed".

   leon breedt pointed out that Perl and Python aren't split up nearly as
   aggressively. He also mentioned the idea of having a ruby-core virtual
   package that installs all the packages, however "even this compromise was
   not deemed acceptable by the Debian maintainers...although this is
   complete hearsay as I heard it on IRC, so, take it with a tonne of salt".

  [Comparing two files for equality]
  ----------------------------------

   Edgardo Hames asked for the easiest way to determine if two files contain
   the same data and Joel VanderWerf gave the elegant

  require 'fileutils'
  p FileUtils.cmp(file[0], file[1])

  [[SUMMARY] Animal Quiz (#15)]
  -----------------------------

   Last week's [Ruby Quiz] was by Jim Weirich:

  "It works like this. The program starts by telling the user to think
  of an animal. It then begins asking a series of yes/no questions
  about that animal: does it swim, does it have hair, etc. Eventually,
  it will narrow down the possibilities to a single animal and guess
  that (Is it a mouse?)."

   If it fails to guess correctly, the user is asked to say what the animal
   was and give a new question that can be used to distinguish it from the
   incorrect answers the program gave. In this way the program learns to
   deal with new kinds of animals.

   James Edward Gray II summarised the solutions people posted (with much
   quoting of Jim). "Everybody solved this one using pretty much the same
   technique" which was to represent the problem as a binary tree, where
   nodes are questions and the branches correspond to yes or no. Each leaf is
   a list of possible animals. The summary also included some ideas from Jim
   on problems with this approach and possible improvements.

  [[QUIZ] Paper Rock Scissors (#16)]
  ----------------------------------

   James Edward Gray II introduced this week's [Ruby Quiz]:

  "Your task is to build a strategy for playing the game of Paper Rock Scissors
  against all manner of opponents. The question here is if you can adapt to an
  opponent's strategy and seize the advantage, while he is doing the same to you
  of course."

  [Documenting ruby.h and intern.h]
  ---------------------------------

   Brian Palmer was writing his first C extension for Ruby and was having
   trouble using rb_const_get and related functions (used for looking up
   constants). "The Pickaxe 2.0 has a wonderful section on C extensions, for
   the most part, but it seems to omit mention of rb_const_get completely.
   Took me an hour of searching the ml to even discover its existence."

   E S explained how to use the function and Charles Mills suggested
   rb_path2class which can be used like

  VALUE cGlitVec = rb_path2class("GLIT::Vec");

   Charles also felt that all the functions, macros and so on in ruby.h and
   intern.h should be documented and to this end volunteered to help with
   this. README.EXT has much good information but is incomplete.

   E S also volunteered to help and weighed up putting the documentation on a
   Wiki versus having it included inline in the Ruby source code (to be
   extracted by rdoc).

   James Britt [announced] he'd run the Doxygen tool over the Ruby source
   code to provide [some documentation on ruby-doc.org]. This lists all the
   functions, macros, structures etc. and their arguments, but lacks the
   human touch.

  [My regexp stupidity needs assistance before loose all my hair!]
  ----------------------------------------------------------------

   trans. (T. Onoma) was having trouble with regular expressions. He wanted
   to match text containing tags like [Hello] and extract the 'Hello'.
   Because the regular expression was being "greedy" (which means it matches
   as much text as it can), it was matching past the closing ']' so that for
   example '[Hello] there [World]' would match as 'Hello] there [World'.

   Here are three possible regular expressions. (To simplify the example we
   use <Hello> instead of [Hello] so we don't have to escape the '[' and
   ']'.) The first regexp is incorrect - it is "too greedy" - while the
   second and third produce the desired behaviour.

  /<(.*)>/
  /<(.*?)>/
  /<([^>]*)>/

   By using the ? modifier, the second regular expression makes the match
   non-greedy. The third regexp works by matching a '<' followed by any
   number of characters apart from '>' until finally a '>' is reached.

   In response to trans' frustration with regular expressions, John Carter
   gave some hints for dealing with them.

     * "Always use the %r{}x form of regexs. This neatly avoids the leaning
       toothpick syndrome when\/matching\/paths" For example, %r{.*} can be
       used instead of /.*/. Any characters can be used to bound the regular
       expression - the editor of this RubyNews is fond of %r|.*|.

     * "The x modifier allows you to use white space and even comments within
       the regex to make it readable. (Larry Wall of perl fame regrets he
       didn't make it the default...)"

     * "Pull the development of the regex outside the development of your
       app. Unit tests are good for that, or even if you just make a wee
       small script or do it on the command line or in irb."

     * "If you are doing it on the command line beware of nasty interactions
       between the string and quoting conventions of the shell and ruby."

     * "Grow the regex slowly. Start with the smallest thing, make it match.
       If you immediately write down a large regex, odds on it will match
       nothing."

  [[suby-ruby] Your all time desired fundemental Ruby mod]
  --------------------------------------------------------

   trans asked "Let say you're Matz, but without any of the pressures of
   keeping up with a previous version of Ruby. What one thing above all
   others would you like to see differ about Ruby?" There were almost 100
   responses.

   Glenn Parker suggested support for operating-system threads and several
   people concurred. John Carter and Austin Ziegler disagreed and preferred
   Ruby's existing threading model, however Austin also wrote "[r]ight now,
   Ruby can't be safely used with multithreaded applications or libraries;
   that should change if at all possible. This probably means that we need
   OS-level threading, but I'd love to keep Ruby's green threads as it's all
   that I've ever needed."

   Many said a "truly cross-platform GUI" would be great (to quote James
   Edward Gray II as an example).

   There was a big discussion on changes to the way class variables work, and
   Matz also said "[i]nitializing module instance variables are one of the
   things I want to fix", but he isn't sure how.

  [ruby-dev summary 25373-25479]
  ------------------------------

   Masayoshi Takahashi posted a summary of the Japanese mailing list
   ruby-dev. In it, Akr had suggested making the next Ruby 1.8 version warn
   when IO#read or IO#readpartial were called with an IO object that had been
   set to non-blocking mode. Back on ruby-talk, Florian Gross asked what the
   problem was with non-blocking IO.

   Tim Sutherland pointed out a post by Tanaka Akira from March 2004 giving
   [some reasons why non-blocking IO can be problematic] and Tanaka replied,
   this time explaining why non-blocking IO can be useful.

  [Best ways to accelerate Ruby's popularity]
  -------------------------------------------

   Back at the end of 2004, Thursday began a thread thinking about what the
   Ruby community can do to make Ruby more popular. The thread has been a
   popular one, gathering over 170 responses so far (not counting several
   sub-threads that were created).

   Ben Giddings reopened the thread this week by suggesting some problems
   with current Ruby websites:

     * "inconsistent look and feel between the various ruby-related domains
       ruby-lang.org vs. rubyforge vs. ruby-doc.org vs. rubygarden vs. RAA"

     * "Duplicated information on every site. RubyForge has a link to report
       a bug in Ruby itself, ruby-doc.org has a link to download Ruby
       directly, etc."

     * "Most ruby sites home pages are geared towards long-time Ruby users,
       and not newbies."

     * "Finally, there's the issue of news and discussion. Easily 90% of the
       screen space on www.ruby-lang.org is dedicated to news, but the last
       bit of news was on Christmas."

   He later added

  "Yeah, as I wrote that, I realized how many important ruby sites there
  are out there. Even I know that I'll find Python at python.org, Perl at
  perl.org, but ruby...
   
  Ruby's most central site is "ruby-lang.org".
  Documentation is at "ruby-doc.org"
  Some applications are hosted at "rubyforge.org"
  Other applications are listed at "raa.ruby-lang.org"
  The old pickaxe, and some documentation is at "rubycentral.com"
  The wiki is at "rubygarden.org"
  The mailing list archives are at "ruby-talk.org" (and blade.nagaokaut.ac.jp)
   
  That's a whole lot of URLS, all of which are fairly important.
   
  So right now "ruby.org" is held by "netidentity.com", who brag about
  owning over 15,000 popular surname-based domain names."

   There was interest in trying to get this domain for Ruby ([Possible
   proposal for ruby.org domain]), and some RubyCentral folk are working on
   the case.

   Improvements to the layout of sites like [ruby-doc.org] were discussed at
   length, with several mockups posted.

  [Xpath like syntax]
  -------------------

   Luke Galea was interested in navigating Ruby objects using a similar
   syntax to XPath for XML. This would let you write code similar to
   Countries/Provinces/Cities[ @name = "London" ].

   Several different syntaxes and implementations were proposed.

New Releases
------------

     * [ruby-oci8 0.1.9]

           KUBO Takehiro made some API improvements to [ruby-oci8], a library
           for connecting to Oracle 8 and later. Support for Oracle Instant
           Installer was also added allowing the library to be used without
           having to manually install Oracle client libraries first.

     * [solaris-kstat 0.2.0]

           Daniel Berger was happy to announce the release of [solaris-kstat]
           0.2.0, a wrapper for the kstat library which provides kernel
           performance statistics under the Solaris operating system.

     * [Tar2RubyScript 0.4.4]

           Erik Veenstra released [Tar2RubyScript] 0.4.4, fixing a bug to do
           with read-only files. Tar2RubyScript transforms a directory of
           code into a single Ruby script, simplifying deployment of the
           application.

     * [RubyScript2Exe 0.3.2]

           Erik Veenstra also released [RubyScript2Exe] 0.3.2, fixing some
           bugs including one which occured when the path to ruby.exe had a
           space in it. This is a tool that collects your Ruby program along
           with the Ruby interpreter and libraries into a single compressed
           executable for Windows or Linux.

     * [WWW::Mechanize alike in Ruby]

           Michael Neumann ported the Perl WWW::Mechanize library to Ruby
           after reading about the web-testing thread in the Previous
           RubyNews. It makes it easier to simulate a web browser client by
           handling cookies, automatic redirection, forms and links.

     * [Rails 0.9.4: Caching, filters, SQLite3...]

           David Heinemeier Hansson announced "[a]nother incredibly strong
           release" of the [Rails] web application framework, including a new
           caching module, SQLite3 database support, plus the ability to
           write code like "45.minutes + 2.hours + 1.fortnight" (the latter
           idea was presented by Richard Kilmer at RubyConf 2004).

     * [RedCloth 3.0.1 -- Humane Text for Ruby]

           [whytheluckystiff] fixed some bugs in [RedCloth] 3, a library for
           writing stylised text which can be converted into HTML. It has
           support for Textile markup and also limited Markdown support.

     * [IHelp 0.2.0]

           Ilmari Heikkinen passed out [IHelp] 0.2.0, a library which
           provides context-dependent documentation on objects and methods in
           irb.

     * [Text::Reform 0.2]

           Kaspar Schiess was proud to announce the first release of
           [Text::Reform], a port of the Perl library Text/Reform. It is used
           to wrap text in a flexible manner.

     * [Lafcadio 0.7.0, 0.6.1: Excessively Clever Query Caching]

           Francis Hwang released both a new development version and new
           stable version of [Lafcadio], an object-relational mapping library
           for use with MySQL. Caching of selects has been added so if a
           query is to be performed that is a subset of an earlier query,
           results cached in memory will be used.

     * [Ruby/ManageSieve 0.2.0]

           Andre Nathan improved [Ruby/ManageSieve], a pure-Ruby library that
           implements the MANAGESIEVE protocol, allowing one to manage Sieve
           scripts. The sievectl tool now supports multiple accounts.

     * [Logtails 0.3: integration with KDE]

           Bauduin Raphael announced KDE integration for [Logtails], a GUI
           tool used to monitor several logfiles at the same time. This
           support was contributed by Richard Dale.

     * [aeditor-2.1 (megacorp release)]

           Simon Strandgaard added folding and bookmarks to [AEditor], a
           console editor for programmers.