From: ptkwt@...1.aracnet.com (Phil Tomson)
Date: 2001-10-04T07:46:14+09:00
Subject: [ruby-talk:22034] Re: Marshal won't dump a Proc

In article <20011004.063633.2113903881.13076@zipworld.com.au>,
HarryO <harryo@zipworld.com.au> wrote:
>In article <1002126975.600438.16806.nullmailer@ev.netlab.jp>, "Yukihiro
>Matsumoto" <matz@ruby-lang.org> wrote:
>
>
>> Procs, Bindings and Continuations contain references to C stack
>> information which is not portable.  Methods have references to C
>> function.  All of above information is not portable.
>

This seems reasonable, but it also means that I can't use Proc's with 
dRuby since dRuby uses Marshalling. :-(  I was thinking of sending Proc's 
over to objects running on different machines (using dRuby).

>
>What I might be able to do is provide two means of constructing the
>object, one by attaching a block and the other by passing a string that's
>eval-ed into a Proc for run-time use and dumped/restored  for persistence.
>

I'm not sure I totally understand what you are doing, but it seems like 
you're having the user supply a function to your class (a Proc) that is 
used to supply a sequence of numbers (am I right?).  What if you had a 
module called UserSupplied (for example) that got included into your 
class?  The user would have to define a function in the UserSupplied 
module.

Something like:
#file: UserSupplied.rb
module UserSupplied

  def myUserFunction
     puts "In myUserFunction"
  end
  #user can edit this file to add or change functions in this
  #namespace.
end

#file: YourClass.rb
class YourClass
   include UserSupplied

   def initialize
      load "UserSupplied.rb"  #this would ensure that if the user changes
                           #UserSupplied.rb after the program began to
                           #run that the new or changed functions in 
                           #the UserSupplied module would get mixed in.
                           #(at least I think it should work, I haven't
                           #tried it :)
   end
end


Would this work for you?  I guess the drawback is that your users would 
have to know Ruby, but even with your other method where they supply a 
string with Ruby code they would have to know Ruby, so I guess it doesn't 
matter.

Phil