From the Examples:

    fart => [ :fart, [] ]
    fart 1 => [ :fart, 1 ]
    fart 1, 2 => [ :fart, [ 1, 2 ] ]

Why isn't the single argument call:

    fart 1 => [ :fart, [ 1 ] ]

?

ps. this is also fun: http://parsetree.rubyforge.org/ruby_parser/