module Ruby2JS
  class Converter

    # (block
    #   (send nil :x)
    #   (args
    #     (arg :a))
    #   (lvar :a))

    handle :block do |call, args, block|

      if
        @state == :statement and args.children.length == 1 and
        call.children.first and call.children.first.type == :begin and
        [:irange, :erange].include? call.children.first.children.first.type
      then
        var = args.children.first
        expression = call.children.first.children.first
        comp = (expression.type == :irange ? '<=' : '<')
        "for (var #{parse var} = #{ parse expression.children.first }; " +
          "#{ parse var } #{ comp } #{ parse expression.children.last }; " +
          "#{ parse var } += #{ parse call.children[2] }) " +
          "{#@nl#{ scope block }#@nl}"
      else
        block ||= s(:begin)
        function = s(:def, nil, args, block)
        parse s(:send, *call.children, function)
      end
    end
  end
end