From: Joe Van Dyk <joevandyk@...>
Date: 2005-12-23T09:55:51+09:00
Subject: Re: String > Integer Conversion Problem

On 12/22/05, Matthew Feadler <matthew@feadler.com> wrote:
> Jacob Fugal wrote:
> > def read_arguments
> >   arg0, arg1 = ARGV.map{ |n| Integer(n) }
> >   raise ArgumentError if arg0.nil? or arg0 < 0
> >   raise ArgumentError if arg1.nil? or arg1 < 0
> >   raise ArgumentError if arg0 > arg1
> >   return arg0, arg1
> > rescue ArgumentError
> >   print <<-USAGE
> > Usage
> > USAGE
> >   exit
> > end
> >
> > a, b = read_arguments
>
> Very nice.  I like this construction.  However, I believe the above will
> throw the exception when I have only one valid arg, which is not what I
> want (1 or 2 args is  correct; no more, no less).
>
> So, it should look like this, yes?
>
> def read_arguments
>   arg0, arg1 = ARGV.map{ |n| Integer(n) }
>   raise ArgumentError if (ARGV.length == 0) or (ARGV.length > 2)
>   raise ArgumentError if (arg0 < 0) or (!arg1.nil? and (arg1 < 0))
>   raise ArgumentError if !arg1.nil? and (arg0 > arg1)
>   return arg0, arg1
> rescue ArgumentError
>   print <<-USAGE
> Usage
> USAGE
>   exit
> end
>
> a, b = read_arguments

Write the damn tests, man!  :-)

If it passes the tests, it should work, unless you have faulty tests,
in which case you need more/better tests.