From: Steven Arnold <stevena@...>
Date: 2005-09-18T01:06:49+09:00
Subject: macros/little languages?

Hi,

I have just recently learned Ruby and I really enjoy it.  One thing I  
have not found that would be nice is a facility for easily developing  
little languages based on Ruby, sometimes referred to as a macro  
facility.

I say "based on Ruby" because I would like to be able to specify that  
a certain block is to be interpreted as standard Ruby.  For example,  
it might be nice if I could do something like:

defworkflow MyAction
     conditions
         <std-ruby-expr>
     end
     action
         <std-ruby-expr>
     end
     cleanup
         <std-ruby-expr>
     end
end

This might be the beginning of a general workflow system.  A workflow  
action has certain conditions that must hold before its action can be  
invoked; an action that then can take place; and cleanup to take care  
of any loose ends.

So my questions:

(1) Are there any tools out there that do something like this now?
(2) Is there any way to get Ruby to compile a block of code  
programmatically without executing it?  I.e. compile the code and  
return me the bytecodes.
(3) Given a set of bytecodes, is there a programmatic way to cause  
Ruby to execute them?

Thanks in advance,
steve