Code Golf: Numeric Ranges

Answer 1

Ruby, 165 characters

a=[]
def o(a)print "#{@s}#{a[0]}#{"#{a.size<3?',':' -'} #{a[-1]}"if a.size>1}";@s=', 'end
ARGV[0].split(', ').each{|n|if a[0]&&a[-1].succ!=n;o(a);a=[]end;a<