From: RLMuller <RLMuller@...>
Date: 2003-05-15T04:06:43+09:00
Subject: Re: ruby_run() w/o exit?

Hi,

I'm a Ruby newbie,  so I was interested in the techniques used in this
thread.  At the risk a appearing impertinent,  below is the program I
synthesized from the various posts on about this:  If nothing else,
it works nicely according to my taste :-)


dummy = <<"PURPOSE"
 call a ruby function in a safe way.
 translate ruby errors into c++ exceptions.
PURPOSE

class MyTest
 class TooPainFulError < StandardError; end

 def initialize
  @langs = %w(ruby c perl java idl bash sh zsh tcsh csh fortran c++)
 end

 def rank lang
  l = lang.downcase
  raise NotImplementedError, lang unless i = @langs.index(l)
  case i
   when 0
    raise TooPainFulError, lang
   else
    puts "#{lang} is my ##{i+1} ranked language"
  end
 end
end

MyTest.new.rank "C"
MyTest.new.rank "NoLang"




----- Original Message ----- 
From: <dblack@superlink.net>
To: "ruby-talk ML" <ruby-talk@ruby-lang.org>
Sent: Wednesday, May 14, 2003 1:30 PM
Subject: Re: ruby_run() w/o exit?


> Hi --
>
> On Thu, 15 May 2003, Simon Strandgaard wrote:
>
> > BTW: I fixed your class so that it works correctly now.
>
> Almost :-)
>
> > class Howard
> >   class TooPainFulError < StandardError; end
> >
> >   def initialize
> >     @langs = %w(ruby c perl java idl bash sh zsh tcsh csh fortran c++)
> >   end
> >
> >   def rank lang
> >     raise NotImplementedError, lang unless @langs.index lang
>
> You've eliminated the assignment to i, which means that this:
>
> >     case lang
> >   when /[^+]$/
> >     puts "#{lang} is my ##{i} ranked language"
>
> raises an exception.  The original line:
>
>       raise NotImplementedError, lang unless i = @langs.index lang
>
> didn't parse.  Ara, in cases like this you might have to compromise on
> the boycotting of parentheses :-)
>
>    raise NotImplementedError, lang unless i = @langs.index(lang)
>
>
> David
>
> -- 
> David Alan Black
> home: dblack@superlink.net
> work: blackdav@shu.edu
> Web:  http://pirate.shu.edu/~blackdav
>
>