proposal: map method for getoptlong

usually, when using getoptlong, one wants to test if an option was set,
and (if it requires an argument) to which value. To make that test easier,
I propose that getoptlong be extended with a map method. The following
script makes that extension and then tests it; try it first with the -h
option:

#!/usr/bin/ruby

require 'getoptlong';

class GetoptLong

   # map getoptlong options to global variables named after their
   # (optionally prefixed) main name. 
   # Usage example:: link:../getoptlong_example

   def map(*prefix)
      loop do
        option_name, option_argument = get_option
        break if option_name == nil
        eval "$#{prefix||''}#{option_name.tr('-','')} = " + 
             "#{option_argument=='' ? 'true' : 'option_argument'}"
      end
   end
end

opt = GetoptLong.new(
   [ '--help',   '-h', GetoptLong::NO_ARGUMENT ],
   [ '--short',  '-s', GetoptLong::OPTIONAL_ARGUMENT ],
   [ '--offset', '-o', GetoptLong::REQUIRED_ARGUMENT ]
).map('opt_')

if $opt_help 
   puts <<-EOF
   You can run #{$0.sub(/.*\//,'')} with the following options:
       --help   or -h (no argument) prints this help
       --short  or -s (no argument) prints option information
       --offset or -o (requires an argument) prints option information
   EOF
   exit
end

puts "$opt_short  was #{$opt_short ? 'set' : 'unset'}, "+
     "it's class is #{$opt_short.class} and "+
     ( $opt_short ? "it contains #{$opt_short}" : "is empty" )

puts "$opt_offset was #{$opt_offset ? 'set' : 'unset'}, "+
     "it's class is #{$opt_offset.class} and "+
     ( $opt_offset ? "it contains #{$opt_offset}" : "is empty" )


-- 
Wybo Dekker