From: Joel VanderWerf <vjoel@...>
Date: 2008-03-30T02:15:14+09:00
Subject: Re: stumped

Joel VanderWerf wrote:
> Jeff Patterson wrote:
>> #run method inherited from Netlist super class
>>    def run()
>>   cmd=''
>>   print "ready>"
>>   while((cmd=gets) !~ /^\.$/)
>>      begin
>>              eval cmd,binding()
>>            rescue Exception=>e
>>        puts e.message
>>      end
>>        print "ready>"
>>      end
>>       end
>> end
> 
> One suggestion: use readline. It's more user friendly.

On second thought, since you're evaling the input, you might want to 
hook your simulation engine up to irb. This uses readline, too, but has 
the advantage of maintaining program state between lines, so that you 
can define local vars, methods, etc. Also, it accepts multiline inputs.

This is the snippet I start from when I want to do that:

require 'irb'
require 'irb/completion'

module IRB
   def IRB.parse_opts
     # Don't touch ARGV, which belongs to the app which called this module.
   end

   def IRB.start_session(*args)
     unless $irb
       IRB.setup nil
       ## maybe set some opts here, as in parse_opts in irb/init.rb?
     end

     workspace = WorkSpace.new(*args)

     if @CONF[:SCRIPT] ## normally, set by parse_opts
       $irb = Irb.new(workspace, @CONF[:SCRIPT])
     else
       $irb = Irb.new(workspace)
     end

     @CONF[:IRB_RC].call($irb.context) if @CONF[:IRB_RC]
     @CONF[:MAIN_CONTEXT] = $irb.context

     trap 'INT' do
       $irb.signal_handle
     end

     custom_configuration if defined?(IRB.custom_configuration)

     catch :IRB_EXIT do
       $irb.eval_input
     end

     ## might want to reset your app's interrupt handler here
   end
end

class Object
   include IRB::ExtendCommandBundle # so that Marshal.dump works
end

if __FILE__ == $0
   x = Object.new
   puts "\nStarted irb shell for x"
   IRB.start_session(x)
   puts "\nStarted irb shell for x with current binding"
   IRB.start_session(binding, x)
   puts "\nRestarted irb shell for x with current binding"
   $irb.eval_input
   puts "\nExited irb shell"
   p x
end

-- 
       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407