class Sass::SCSS::Parser

def for_directive
  tok!(/\$/)
  var = tok! IDENT
  ss
  tok!(/from/)
  from = sass_script(:parse_until, Set["to", "through"])
  ss
  @expected = '"to" or "through"'
  exclusive = (tok(/to/) || tok!(/through/)) == 'to'
  to = sass_script(:parse)
  ss
  block(node(Sass::Tree::ForNode.new(var, from, to, exclusive)), :directive)
end