From: Mauricio Fernandez <mfp@...>
Date: 2006-11-01T07:09:02+09:00
Subject: Re: Puzzling over why ri can open the std ruby/ri .yaml files, but raw yaml can't

On Wed, Nov 01, 2006 at 06:05:12AM +0900, Eric Promislow wrote:
> About to yaml <<c:/ruby/share/ri/1.8/system/Abbrev/cdesc-Abbrev.yaml>>
> I get this error:
> c:/ruby/lib/ruby/1.8/yaml.rb:133:in `transfer': invalid subclass
> (TypeError)
>         from c:/ruby/lib/ruby/1.8/yaml.rb:133:in `load'
>         from get_yaml_info.rb:19:in `get_class_info'
>         from get_yaml_info.rb:19:in `get_class_info'
>         from get_yaml_info.rb:25
> 
> ruby 1.8.4 (2006-04-14) [i386-mswin32]
> 
> It's the same code, and I don't see ri setting any options in the YAML
> namespace telling it to process types like "!ruby/struct:SM::Flow::P"
> differently, although I gather this is the problem.
> 
> Any advice?

$ cat ri-problem.rb 
require 'yaml'
require 'pp'

class RiFinder
  def initialize(sysdir)
    @sysdir = sysdir
  end

  def get_class_info(clsName, info)
    clsFile = "#{@sysdir}/#{clsName}/cdesc-#{clsName}.yaml"
    puts "About to yaml <<#{clsFile}>>"
    clsInfo = File.open(clsFile) { |io| YAML.load(io) }
    pp clsInfo
  end
end

rifinder = RiFinder.new("/usr/share/ri/1.8/system/")
rifinder.get_class_info("Abbrev", nil)

$ ruby ri-problem.rb 
About to yaml <</usr/share/ri/1.8/system//Abbrev/cdesc-Abbrev.yaml>>
/home/batsman/usr//lib/ruby/1.8/yaml.rb:133:in `transfer': invalid subclass (TypeError)
	from /home/batsman/usr//lib/ruby/1.8/yaml.rb:133:in `node_import'
	from /home/batsman/usr//lib/ruby/1.8/yaml.rb:133:in `load'
	from /home/batsman/usr//lib/ruby/1.8/yaml.rb:133:in `load'
	from ri-problem.rb:12:in `get_class_info'
	from ri-problem.rb:12:in `open'
	from ri-problem.rb:12:in `get_class_info'
	from ri-problem.rb:18
$ echo 'require "rdoc/ri/ri_reader"' | cat - ri-problem.rb > ri-no-problem.rb
$ ruby ri-no-problem.rb 
About to yaml <</usr/share/ri/1.8/system//Abbrev/cdesc-Abbrev.yaml>>
#<RI::ClassDescription:0xa7db27f0
 @attributes=[],
 @class_methods=[],
 @comment=
  [#<struct SM::Flow::P
    body=
     "Calculate the set of unique abbreviations for a given set of strings.">,
   #<struct SM::Flow::VERB
    body=
     "  require 'abbrev'\n  require 'pp'\n\n  pp Abbrev::abbrev(['ruby', 'rules']).sort\n">,
   #<struct SM::Flow::P body="<em>Generates:</em>">,
   #<struct SM::Flow::VERB
    body=
     "  [[&quot;rub&quot;, &quot;ruby&quot;],\n   [&quot;ruby&quot;, &quot;ruby&quot;],\n   [&quot;rul&quot;, &quot;rules&quot;],\n   [&quot;rule&quot;, &quot;rules&quot;],\n   [&quot;rules&quot;, &quot;rules&quot;]]\n">,
   #<struct SM::Flow::P
    body="Also adds an <tt>abbrev</tt> method to class <tt>Array</tt>.">],
 @constants=[],
 @full_name="Abbrev",
 @includes=[],
 @instance_methods=[#<RI::MethodSummary:0xa7db3024 @name="abbrev">],
 @name="Abbrev",
 @superclass=nil>

-- 
Mauricio Fernandez  -   http://eigenclass.org   -  singular Ruby